Checking the operation of the mechanism for lifting the load of the crane in the mode of unsteady movement. Lubrication of crane gearboxes depending on the load capacity and operating modes of the crane Drums installed in the load lifting mechanism

1. GENERAL INSTRUCTIONS

2. SELECTION OF THE MULTIPLICITY OF THE POLYSPAST

3. SELECTION OF ROPE DIAMETER

n1.doc

Introduction

1.Steel rope

2. Hook suspension

3. Drum

4. Electric motor

5.Reducer

6.Elastic clutch with brake pulley

7. Shoe brake

Literature

Appendix

Cargo drum device

Winding the rope of the cargo drum

EXERCISE

04.11.2020

Ministry of Education of the Russian Federation

St. Petersburg Institute of Mechanical Engineering

(VTUZ-LMZ)

Department "Theory of mechanisms and machine parts"

BRIDGE CRANE

LIFTING MECHANISM

Saint Petersburg

Load lifting mechanism. Guidelines for course work for students of PIMash mixed and evening education of all specialties. The procedure for calculating the elements of the mechanism, the method for calculating the lifting mechanism are outlined, reference data on the choice of elements of the lifting mechanism are given.

Revision 1987 Compiled by: ass. .

Scientific editor: Ph.D. tech. sciences, associate professor.

Edition 2000 Compiled by: Art. teacher .

Scientific editor: dr. tech. sciences, prof. Yu.A. Derzhavets.

Purpose of the guidelines- practical assimilation of the course "Hoisting and transport machines" section: "Machines of periodic action", "Cranes".

The volume of course work- an explanatory note on sheets of A4 format (up to 20 pages) and a drawing of the unit on a sheet of A2 format, which are carried out in accordance with the requirements of ESKD. All calculations are done in the SI system.

Design object- lifting mechanism, drum, suspension.

Schematic diagram of the mechanism- components of the mechanism, Fig. 1:

1 - electric motor;

2 - brake with brake clutch;

4 - drum and suspension (not shown in the figure).

Operating loads- Figure 2 shows the force (load capacity) applied to the suspension hook 3.

Exercise- placed in the Appendices, the initial data for design are given:

load capacity ;

The speed of the mechanism for lifting the load;

Lifting height;

Mode of operation of the mechanism: L - light, C - medium, T - heavy, BT - very heavy.

Task execution sequence:

1) The choice of multiplicity of the chain hoist.

2) choice of rope diameter.

3) Determining the block diameter.

4) Determining the dimensions of the drum and its rotational speed.

5) Motor selection.

6) Gear selection.

7) Choice of brake clutch.

8) Brake selection.

9) Verification calculation of the electric motor according to the start time of the lifting mechanism.

10) Verification calculation of the brake according to the braking time of the lifting mechanism.

GENERAL INFORMATION

In overhead (gantry, etc.) cranes, the mechanism for lifting the load is placed on the crane trolley. The scheme of the lifting mechanism for cranes for general and special purposes depends on many factors: the type of lifting device, the mass of the load being lifted, the lifting height, etc. The general schematic diagram of the lifting mechanism, typical for cranes with a lifting capacity of 5 ... 50 tons, is shown in Fig. 1 .

Fig.1. Kinematic diagram of the mechanism for lifting the load.

The scheme of the load lifting mechanism allows block assembly of units using standard elements: an electric motor 1, a brake with a brake clutch 2, a gearbox 3, a drum 4 and a suspension (not shown in the diagram). This layout of the load lifting mechanism is most common in mass production, it is widely used and is typical for cranes of small and medium capacity.

In addition to the considered scheme, other layouts of the load lifting mechanism are possible, such as schemes with a torsion shaft, with an open gear, etc.

To gain in tractive effort in the lifting mechanisms, a poly and spa t is used, which is a system of movable (in a hook suspension) and fixed (bypass) blocks.

For the adopted scheme of the lifting mechanism, one should choose the type of chain hoist, determined by the scheme of winding the rope onto the drum and pressing the rope , , .

When directly winding the rope onto the drum (bridge, gantry, jib cranes), in order to avoid displacement of the load during its ascent and descent and to uniformly load the drum support, double chain hoists are used

Fig.2. Scheme of a double chain hoist. 1 - drum; 2 - equalizing block (bypass); 3 - suspension; 4 - rope (flexible traction body).

When using double chain hoists, two branches of the rope are simultaneously wound on the drum. Depending on the lifting capacity of the crane, the multiplicity of the chain hoist is chosen. An increase in the multiplicity per unit is achieved by replacing the equalizing block with the opposite side of the chain hoist; the process can be repeated until any multiplicity is reached.

The required multiplicity of the chain hoist for the lifting mechanism is given in Table 1.

Table 1

MULTIPLICITY OF THE LOAD LIFTING MECHANISM 0 " style="border-collapse:collapse">

The nature of the winding on the drum

Pulley type

Lifting capacity, T

Directly on the drum (overhead, gantry, jib crane)

double

Through the guide block (shooting cranes)

https://pandia.ru/text/78/240/images/image010_27.gif" width="33" height="24">

where: https://pandia.ru/text/78/240/images/image011_21.gif" width="15" height="19 src="> - safety margin of the rope from the mode of operation (L - 5; C - 5 .5; T and BT - 6);

https://pandia.ru/text/78/240/images/image013_18.gif" width="131" height="49"> The maximum tension, KN, of the rope is determined

where: - lifting capacity of the crane, t, Appendix 1;

https://pandia.ru/text/78/240/images/image014_21.gif" width="24" height="20 src=">

The diameter of the steel rope is selected according to Table 3 according to the condition (1). The most widely used ropes are double lay of marked groups =1600...1800 MPa. At lower values of marking groups, the diameter of the rope, and, consequently, the drum and blocks, is irrationally increased, and at higher values, the rope has increased rigidity, which reduces its service life.

Table 3

CHARACTERISTICS OF DOUBLE LAY ROPES

	Cross-sectional area,	Weight of 1000 m rope,	Breaking strength of the rope by marking groups, kN


Type LK-R construction 6x19 1+6+6/6 + I o. With. (GOST 2688-80)





















Type TLC-0 design 6x37 1+6+15+15 + I o. With. (GOST 3079-80)

LUBRICATION OF LIFT AND TRANSPORT EQUIPMENT

The most common electric bridge, slewing, cantilever, metallurgical and other cranes have much in common in the lubrication system, but, depending on various operating conditions, they also have their own characteristics.
Lubrication of crane gearboxes of the mechanism for lifting loads and the mechanisms of movement of the bridge and trolley is usually carried out by means of an oil bath. Since the gears in crane gearboxes operate under severe conditions, with impact loads, frequent switching on and off, then they use more viscous and oily oils compared to conventional machine tool gearboxes. When filling crane gearboxes with oil, it is recommended to use the instructions given in Table 21.

Table 21
Lubrication of crane gearboxes depending on the load capacity and operating modes of the crane

Changing the oil and flushing the gearboxes is done once every 4-6 months and is usually timed to a scheduled repair or inspection of the crane. For metallurgical cranes, the oil life is reduced to 2-3 months. Before opening gearboxes, remove dust from their covers to prevent it from getting into the oil. The oil level in the gearbox must not be lower than the control mark of the oil indicator; in its absence, it is recommended to fill the oil no higher than the level reaching 3-5 cm to the bottom of the lower shaft, but not lower than the level that ensures the full height of the teeth of the lower gear wheel is immersed in the oil. Gearboxes must not have oil leaks. It is especially unacceptable to hit trolleys, crane bridge flooring and rails, as well as brake pulleys, pads and tapes. If leaks are found, they are repaired immediately.
Lubrication of the bearings of crane gearboxes of old designs, where the bearings of the high-speed first shaft of the gearbox have ring lubrication, when operating under normal temperature conditions, is done by filling them once every 3 months with industrial oil 20, topping up once every 3-5 days. In conditions of elevated temperatures and dustiness, these bearings are filled monthly with industrial oil 50, topping up is done 2-3 times a week.
Plain bearings in gearboxes with cap oilers are lubricated at normal temperature with US-2 or USs-2 grease by turning the oiler cover 1-2 turns 1-2 times per shift. At elevated temperatures, they are lubricated with UT-1 or UTs-1 constantin by turning the oiler cap 1-2 turns up to 2-3 times per shift.
In crane gearboxes of modern designs, rolling bearings are usually installed, which at normal temperatures should be filled with US-2 grease once every 4-6 months, and for metallurgical cranes with grease 1-13 or UT-1 constantin at each repair. Lubrication is added monthly through cap or grease fittings connected to these bearings. If there are grease-lubricated rolling bearings in the gearboxes, special attention should be paid to the serviceability of the seals and to prevent the grease from leaking out of the bearing housing or being washed out by leaking oil from the gearbox bath.
On some cranes, a pump is installed in the gearboxes to supply oil to the bearings. In this case, caring for them comes down to monitoring the presence and quality of the oil and the proper operation of the pump.

Bridge travel mechanisms of heavy-duty electric cranes, especially metallurgical ones, are currently produced with centralized lubrication systems from automatic or manual lubrication stations. In this case, lubrication is carried out in accordance with the operating instructions for these systems. The automatic centralized lubrication system provides a reliable supply of lubricant to all lubrication points, including remote and hard-to-reach ones. At the same time, maintenance time is saved, which is especially important for continuously operating cranes, and consumption is also significantly reduced. lubricants.
In cranes of old designs, lubrication of the bushings of the running wheels of the transmission shaft plain bearings is usually carried out through cap greasers, grease fittings or from central lubrication units. Lubrication of cranes operating at normal temperatures, for example, in mechanical assembly shops, is carried out with US-2 or USs-2 grease by turning the grease fitting caps 1-2 turns or filling the grease fittings with a syringe 1-2 times per shift. Lubrication of forging, foundry, muldo-filling and other metallurgical valves is carried out with UT-1 or UTs-1 contaline by turning the covers of the grease fittings by 2 turns or filling the grease fittings 2-3 times per shift. Particular care must be taken when lubricating remote points, bushings of the road wheels and parts and assemblies that are directly exposed to high temperatures. The rolling bearings of the bridge travel mechanisms are lubricated in the same way as the rolling bearings of crane gearboxes.
Low-temperature lubricants TsIATIM-201, NK-30, No. 21, GOI-54, etc. are used as greases for cranes operating outdoors in winter. Lubrication points for outdoor cranes must be protected from snow water entering them.
In the trolley travel mechanism, gears and gear bearings, travel wheel bearings are lubricated in the same way as the corresponding components of the axle travel mechanism. Since the bogie is constantly moving along the bridge, it is especially important here to prevent oil from leaking from the gearboxes onto the deck and rails.
In the load lifting mechanism, the gearboxes and bearings of the load drum are lubricated in the same way as the same units of the bridge and bogie movement mechanism. Since the lifting mechanism works harder than other crane mechanisms, it is recommended to lubricate its components more often. Lubrication of rolling and sliding bearings, axes of hook cages is carried out with grease US-2, at high temperatures with constantin by stuffing through oilers or plugs located at the ends of the axles of the blocks. For cranes operating at normal temperature, lubrication is applied 2-3 times a week, and for metallurgical cranes, at least 1 time per shift. Cage hook ball bearings are filled at normal temperatures with US-2 grease once every 3-6 months, in metallurgical cranes - with Konstaline or grease 1-13 once a month.
To avoid rapid wear, open gears are lubricated: in light-duty cranes with light duty and at normal temperatures - with semi-tar 1 time in 5 days, medium-duty and medium duty at elevated temperatures - with graphite ointment 1 time in 5 days and heavy metallurgical cranes 2 times a week - graphite ointment, prepared by mixing 90% konstaline and 10% graphite powder, when heated not higher than 110 °. Before applying the grease, the old one should be removed.
The lubrication of electric motors is shown below. Drum controller bearings are lubricated with US-2 or US-3 grease, crackers, segments and ratchet wheels - with a thin layer of US-2 grease or technical vaseline. The swivel joints of the contactors are lubricated with industrial oil 30. The parts of the limit switches are systematically lubricated, at least once every 10 days, with the same oil or US-2 grease, depending on design features node. Lubrication of the fingers of current-collecting rollers is carried out with de-energized trolley wires once a week with US-2 grease, and at high temperatures with UT-1 constantin.
In order to avoid accidents, lubrication of cranes should be carried out only in a de-energized state of all crane mechanisms on its landing site. A daily supply of lubricants in clean containers (separate for each grade) should be stored in a closed box on the crane bridge. In view of the danger for crane operators, as well as the presence of a large number of hard-to-reach lubrication points on cranes, it is especially urgent to transfer all units to centralized and automatic lubrication.

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(EPI MISiS)
Faculty: _______________________________

Department: __________________________________

Speciality: ____________________________

Group: ___________________________________

Settlement and graphic work

at the rate of _________________________________

Subject: Lifting mechanism
Done by: ___________________

Checked by: Associate Professor Maltsev A.A.

Protection rated ________________________________________________

"_______" _____________________2008

Elektrostal 2008

Electrostal Polytechnic Institute

Moscow State Institute of Steel and Alloys

(technological university)

(EPI MISiS)

Department of TPM
EXERCISE

For the implementation of the RGR

Group student _____________________________________________

1. Project theme: Load lifting mechanism

2
1 - electric motor

2 - clutch with brake

3 - reducer

4 - drum

5 - hook suspension
. Initial data: Kinematic diagram of the lifting mechanism (Fig. 1)

Load capacity Q = 10 t

Lifting height H = 20 m

Lifting speed V = 0.1 m/s

Operation mode group 6M

Fig.1. Scheme of the lifting mechanism
3. List of questions to be developed:

Learn about the design of an electric winch. Calculate the lifting mechanism: choose a rope; choose a hook suspension; calculate the drum; choose an electric motor; choose a reducer; choose a clutch with a brake pulley; select brake.

Page

Introduction 5

1. Steel rope 6

2. Hook suspension 7

3. Drum 8

4. Electric motor 9

5. Reducer 10

6. Flexible coupling with brake pulley 11

7. Shoe brake 12

Literature 13

Annex 14

In a lifting electroreversible winch (Fig. 2), the engine 9 rotates the drum 2 through the elastic coupling 4 and the gears of the cylindrical gearbox. It is characterized by a rigid kinematic connection of the drum with the engine, in which the direction of rotation of the drum is controlled by changing the direction of rotation (reversing) of the engine.

Fig.2. Winch
The rigid connection of the drum with the engine is carried out by the gear transmission of the gearbox 3.

Starting and reversing the engine is carried out by electric starting equipment: drum controller 7, magnetic starters 8, shoe contactors, etc. This equipment is installed on frame 1 or in a place remote from the winch.

Lifting weight

, (1)

where g\u003d 9.81 m / s 2 - free fall acceleration.

For chain hoists with multiplicity not higher than four, it is permissible to determine the efficiency by the formula

, (2)

where ? bl= 0.98 - block efficiency, ? \u003d 2 - multiplicity of the chain hoist.

The maximum tension of the rope branch when lifting the load is determined by the formula

, (3)

where ? \u003d 1 - coefficient for a single chain hoist.

Rope breaking force

, (4)

where K = 6.0 - safety factor:

Operation mode group ………………….. 2M 3M 4M 5M 6M

Safety factor K …….... 5.0 5.0 5.5 6.0 6.0

We select according to GOST 2688-80 (Table 1) a steel wire rope with a diameter of d k \u003d 22.5 mm (Fig. 3) of a double cross lay LK-R 6Ch19 (1 + 6 + 6/6) + 1o.s. Explanation: LK - linear touch of the wires between the layers in the strands; P - different diameters of the wires in the outer layer of the strand; 6 - six-strand rope; 19 - the number of wires in one strand; 1o.s. - one organic core.

Fig.3. Rope

The hook suspension (Fig. 4) consists of a hook 1, a traverse 2, a support bearing 3, a special nut 4 for attaching the hook to the traverse, clip cheeks 5, movable blocks of the chain hoist 6 and an axle for attaching blocks 7.

Fig.4. hook suspension
We choose a hook suspension with a lifting capacity of 10 tons (Table 2).

Crane hooks with a cylindrical shank are manufactured by hot stamping followed by machining of the shank. Hooks are divided into numbers from 1 to 26 according to the maximum load capacity, and according to the length of the shank - into types A and B: A - with a short shank, B - with a long shank.

The drum diameter is determined by the formula

, (5)

where e \u003d 30 is the coefficient:

Operation mode group …………………………… 2M 3M 4M 5M 6M

Coefficient e …………………………………. 20 20 25 30 30

The winding on the drum will be carried out in one layer.

Let the working length of the drum L 0 = 600 mm, then the number of working turns on a smooth drum

. (6)

Drum rope capacity

The length of the rope wound on the drum at a given lifting height

, ( 8)

which is less than the rope capacity of the drum.

The drum is made from a cast billet or from a pipe. Flanges are welded to the pipe, to which the bottom with hubs with a shaft pressed into them is screwed (Fig. 5).

Fig.5. Drum

Efficiency of the lifting mechanism

, (9)

where? m = 0.98 - coupling efficiency; ? ed \u003d 0.97 - efficiency of the gearbox; ? bar \u003d 0.99 - efficiency of drum bearings; ? floor \u003d 0.96 - efficiency of the chain hoist.

Required motor power when lifting a load

. (10)

We select the MTKF 312-8 crane motor (Fig. 6) with the following technical characteristics (Table 3) and dimensions (Table 4):

power N dv, kW ………………………………………………………………… 11.0

speed n dv, rpm………………………………….………………….. 700

output shaft diameter, mm …………………………………………………… 50

Fig.6. Crane motor
Bearing elements - a body with horizontal ribs and bearing shields are cast from high-strength cast iron. The connection of the cable with the winding of phase rotors is carried out through the holes in the end shields, and the terminal box is located on top, which provides power supply from any side of the motor. The fan is made of aluminum alloy, steel casing.

Drum speed

. (11)
Required gear ratio

. (12)

Estimated torque on the low-speed gearbox shaft

. (13)

We select a two-stage gearbox Ts2-500 (Fig. 7) with the following technical characteristics (Table 5) and dimensions (Table 6):

torque on the low-speed shaft, N m ………….……………. 18000

ratio u ed ……………………………..………………. 100

Fig.7. Reducer

Estimated torque on the high-speed gearbox shaft

. (14)

The elastic sleeve-finger coupling softens shocks and shocks in the drive and prevents dangerous vibrations. It consists of two coupling halves mounted on the shafts, interconnected by fingers with rubber rings or bushings put on them (Fig. 8).

Fig.8. Flexible coupling
We choose an elastic sleeve-finger coupling MUVP-7 (GOST 21424-75) (Table? 7). The clutch is made with a brake pulley.

The calculated braking torque is determined by the formula

, (15)

where TO T= 2, 5 - braking safety factor:

Operation mode group …………… 1M 2M 3M 4M 5M 6M

Braking ratio ……….. 1.5 1.5 1.5 1.75 2.0 2.5

According to the value of the braking torque, taking into account the diameter and width of the brake pulley, the shoe brake TKG-160 is selected (Table 8).

The shoe brake (Fig. 9) consists of a frame 1, two racks 3 and 6 hinged on it with shoes 2 and 7, the working surfaces of which are lined with a friction tape, a rod with a clamp 5 and an opening device with an electro-hydraulic pusher 8.

Fig.9. Shoe brake

Lifting machines: A textbook for universities in the specialty "Hoisting and transport machines and equipment" / M.P. Aleksandrov, L.N. Kolobov, N.A. Lobov and others - M .: Mashinostroenie, 1986. - 400s.
Volkov D.P., Krikun V.Ya. construction machines and means of small-scale mechanization - M .: Mastery, 2002. - 480s.
Fidelev A.S. Hoisting and transport machines - Publishing Association "Vishcha Shkola", 1975. - 220s.
Lifting and transport machines. Atlas of structures, ed. M.P. Alexandrova, D.N. Reshetova, M.: Mashinostroenie, 1987 - 122p.3.
Methodological recommendations for course design / Torshin V.T., Zaitsev E.D., Grinshpun M.I., Kozlov V.A., Kishkin I.V. - MISiS, 2001. - 29s.
Lectures by Associate Professor A.A. Maltsev.

table 1

Steel ropes LK-R 6Ch19 (1+6+6/6)+1 o.s. (GOST 2688-80)

diameter Rope, mm	discontinuous Force, N	diameter Rope, mm	discontinuous Force, N	diameter Rope, mm	discontinuous Force, N
3,6	8780	11,0	83200	28,0	525000
3,8	9930	12,0	95000	30,5	629000
4,1	11550	13,0	107500	32,0	654500
4,5	13300	14,0	131000	33,5	718000
4,8	15200	15,0	152000	37,0	854000
5,1	17200	16,5	184500	39,5	977000
5,6	20950	18,0	220000	42,0	1110000
6,2	25500	19,5	253000	44,5	1225000
6,9	31800	21,0	294500	47,5	1435000
7,6	38000	22,5	333000	51,0	1625000
8,3	46100	24,0	380000	56,0	1980000
9,1	55000	25,5	430000
9,6	64650	27,0	483500

table 2

Hook suspensions

Carrying capacity, t	Number of blocks	Block diameter, mm	Hook number
3,2	1	320	12A
5	2	400	14A
10	3	360	17A
12,5	3	500	18A
16	3	400	19B
20	4	500	20A
25	3	400	21B
32	3	400	22B
32	4	610	22A
50	5	700	24B

table 3

Technical characteristics of crane motors

engine's type	power, kWt	Rotation frequency, rpm
DMTKF 011-6	1,4	875
DMTKF 012-6	2,2	880
DMTKF 111-6	3,5	900
DMTKF 112-6	5,0	910
MTKI 160 L8	7,0	680
MTCF 311-8	7,5	690
MTKI 160 L6	10,0	915
MTCF 312-8	11,0	700
MTCF 411-8	15,0	695
MTCF 412-8	22,0	700
MTKN 511-8	30,0	700
MTKN 512-8	37,0	700
MTKN 512-6	55,0	925

table 4

Dimensions of crane motors

engine's type	l1	l10	l31	l33	b10	b11	H	H31	d	b	h
DMTKF 011-6	60	140	70	407	140	188	112	320	28	8	31
DMTKF 012-6	60	159	70	442	159	210	112	320	28	8	31
DMTKF 111-6	80	190	140	713	220	290	132	342	35	10	38
DMTKF 112-6	80	235	135	574	220	290	132	342	35	10	38
MTKI 160 L	140	254	108	910	254	320	160	410	60	12	45
MTCF 311	110	260	155	637	280	350	180	444	50	14	53,5
MTCF 312	110	320	170	712	280	350	180	444	50	14	53,5
MTCF 411	140	335	175	749	330	440	225	527	65	18	66,4
MTCF 412	140	420	165	824	330	440	225	527	65	18	66,4
MTKN 511	140	310	251	945	380	500	250	570	70	18	71,4
MTKN 512	140	390	271	1054	380	500	250	570	70	18	71,4

table 5

Gearbox Specifications

Gear unit size	Ratio	Torque on the low-speed shaft, Nm
Ts2-250	8, 10,	2500
Ts2-300		3400
Ts2-350		5800
Ts2-400		8000
Ts2-500		18000
Ts2-650		33500
Ts2-750		47500
Ts2-1000		128000

The load drum is one of the most important components of a crane. It is intended for winding and uniform distribution of the rope, which is responsible for lifting or lowering the load. The design of the cargo drum is carefully thought out, because even a slight violation can lead to a strong bend in the rope and interruptions in the operation of the crane itself. To understand how to avoid this, you should carefully understand the drum device.

Drawing of the device of the cargo drum

One piece pipe- the main part of the drum. It is on it that the rope is wound during the operation of the crane. The pipe may have notches on its outer surface, or it may be completely smooth. Below we will consider this point in more detail.
flanges- welded to the ends of the pipe. And to the rim of the flanges, in turn, hubs are attached.
It should be noted that the pressing of the central shaft occurs with the help of the inner surface of the pipe, which has a cylindrical shape.
Gear- located on the central shaft. Its main task is to connect the drum to the gearbox drive so that the structure starts to move.

This process should be considered separately, since the quality of work, as well as the specifics of the cargo drum device, directly depend on it. In order for the rope to be laid evenly on the drum during winding, special grooves are provided on the outer side of the pipe. They prevent rope tangling.

The diameter of the grooves is slightly larger than the diameter of the rope itself, which allows the rope to be easily placed and not come into contact with the sides of the drum. At the same time, on one part of the mechanism, the grooves are directed to the left side, and on the other - to the right. This interesting feature it is necessary that the load move in a vertical plane without horizontal displacements relative to the drum itself.

Advantages such a device of the cargo drum: the load between the cable and the drum pipe is reduced, which allows to increase the service life of the mechanism itself.

Between the grooves themselves is smooth surface. Most often, the ends of the cable are attached to the edges of the drum itself. The rope descending from the drum is connected to the outer blocks of the hook suspension. Therefore, during the winding of the cable, it winds from the edge to the middle part.

Particular attention should be paid to cranes with a large lifting capacity. and multiplicity of the chain hoist. On the drum of such cranes, long sections without winding grooves must be provided. This is necessary for stable operation, however, it leads to an increase in the length of the drum itself and the dimensions of the lifting mechanism.

To eliminate this significant drawback, a different scheme for connecting the cable to the drum is used. The ends of the rope are connected to the edges of the middle part without cutting and then fed to the internal elements of the suspension. Then, during the movement of the load upwards, the rope winds already from the middle to the edges.

GRADUATION PROJECT

Improving the maintenance of the mechanism for lifting the load of the railway crane KZhDE-161

Working conditions

equalizing efficiency

Polyspast multiplicity

rare lubricant

Normal lubrication at normal temperatures

Theme of the project: Improving the maintenance of the mechanism for lifting the load of the railway crane KZhDE-161

Initial data for the project (special instructions for the project)

a) Technical and economic indicators of the enterprise and analysis of existing structures

b) Reference information on railway cranes

c) Reference literature for design calculations

1. Analysis of the existing structure

2. Design calculations of mechanisms

3. Strength calculations of mechanism units

4. Maintenance and crane repair

5. Labor protection

6. Economic part

5 List of graphic material (with precise indication of required drawings)

1. Railway crane (general view).

2. Kinematic schemes of crane mechanisms

3. Load lifting mechanism

4. Boom lifting mechanism

5. Cargo drum

6. Technical and economic indicators of equipment operation

INTRODUCTION

The universal full-revolving self-propelled jib crane on the railway track KZhDE-161 is used in the freight facilities of the UGZhT and is a means of mechanizing loading and unloading operations with various cargoes. This crane is manufactured with a diesel-electric drive.

Diesel-electric crane KZhDE-161 is equipped with a main 15-meter boom with a hook and, on special order, can have additional equipment: a 5-meter insert for extending the boom up to 20 m, a forest grab or grab with a set of ropes, a cargo electromagnet with a motor-generator power station. Crane nodes are maximally unified with crane nodes KZhDE - 251, up to 80% of parts are the same.

The power source of the crane is diesel, which rotates the generator set, which feeds the individual electric motors of all actuators with alternating current of 380 V. It is possible to operate the crane with power from an external network via a flexible cable.

The purpose of the diploma project is to modernize the mechanism for lifting the load and improve its maintenance. Modernization consists in changing the scheme of the mechanism from a single-drum to a two-drum scheme. The double-drum scheme provides lifting or lowering of the load with one drum or two at the same time, since the gearbox is paired. When working with two drums, the lifting speed is doubled, since the chain hoist will work as a double one and its multiplicity will not be six, but three. When working with a double-rope grab, one drum is used as a lifting drum, and the other as a closing one.

1. ANALYSIS OF THE EXISTING DESIGN

The technical characteristics of the crane in question are given below:

Carrying capacity, t

With the smallest overhang 25

At the highest reach 4.9

Boom length, m 15

Speed, m/min

Load lifting 8.8:17.5

Movement 175

Turning part rotation frequency, rpm 2

Boom full lift time, min 0.62

Crane weight in working order 52.5

The KZhDE-161 crane has a running platform, a turntable with a body and mechanisms installed on it, a turntable, an arrow and a hook clip.

The running platform is the base of the crane and consists of a welded frame, the pockets of which are filled with ballast, and standard two-axle bogies on rolling bearings. Under the running frame there are two movement mechanisms, including electric motors and gearboxes, the driven shafts of which are the axles of the running wheels (wheel sets). Brackets of outriggers - outriggers - are welded to the outer bars of the frame. Outriggers increase the stability of the crane by increasing the support base. The outriggers are brought into the transport position by turning them about the axis by 90 0 along the turntable. The outriggers are screwed.

The rotary frame of the KZhDE-161 crane is a welded structure of longitudinal and transverse beams with decking welded to them. Two pairs of inclined posts are pivotally attached to the longitudinal beams, forming the portal supports; boom supports are fixed in front of the frame. A diesel engine and a generator are installed in the tail section of the swing frame on a special cast-iron plate, which simultaneously serves as a counterweight. The fuel tank and radiator are located nearby. It also houses the mechanisms for lifting the load, changing the reach of the boom, turning and the driver's cab with a control panel.

When operating a crane with an electromagnet D.C. gives a motor - a generating station mounted on top of the body. A control panel and a magnetic controller are mounted inside the body.

The slewing bearing of the crane has a ball two-row slewing circle, consisting of three rings. The outer cage consists of two rings: the upper one, which is bolted to the swivel frame, and the lower one, connected by bolts to the upper one. The inner cage is also a rotation ring gear, the cage is fastened with bolts to the frame of the undercarriage. The outer and inner cage has treadmills for two rows of balls. The rolling surfaces are hardened by currents of the high part. The slewing device perceives the load from the mass of the rotary part with the mechanisms located on it, as well as the overturning moment during the lifting of the load.

The mechanism for lifting the load is located in the central part of the turntable.

The kinematic diagram of the load lifting mechanism is shown in Figure 1.

It is planned to place two electric motors 1, a double two-stage gearbox 4, two brakes 3 and two drums 5 on a special welded frame.

Two gearboxes are located in one housing, separated by a partition, which serves as a support for the ball bearings of the shafts.

Through bearing caps are equipped with lip seals that prevent dirt and dust from entering the gearbox and oil leakage from the gearbox. On the plane of the connector, the cover is placed on the body for oil varnish. The gearbox has inspection windows for checking the oil level and a drain hole with a plug.

a) kinematic diagram: 1 - electric motor, 2 - coupling, 3 - brake, 4 - gearbox, 5 - drum; b) cargo rope reeving scheme

Picture 1 - The mechanism for lifting the load of the crane KZhDE -161

The driven shafts of the gearbox end in gear rims, which are half-couplings of gear couplings connecting the shafts to the drums. The second coupling halves are made in the form of plug-in hubs with internal gearing mounted on the axes of the drums and engaging with the gear rims of the driven shafts.

The axis of the drum at one end rests on a spherical ball bearing mounted in the rack, and the other end on the same bearing mounted in the bore of the driven shaft of the gearbox.

The drums are cut for laying ropes. The ends of the ropes are fastened with wedges. The double-drum scheme of the lifting mechanism ensures the lifting or lowering of the load by one drum or two at the same time. In this case, the lifting speed is doubled, since the chain hoist (Figure 1b) will work as a double one and its multiplicity will not be six, but three. When working with a grab, one drum is used as a closing drum.

The boom lift mechanism is distinctive features, namely: the presence of a worm gearbox, as well as an open gear between the gearbox and the drum. The electric motor of the mechanism of communication with the gearbox by means of a connecting elastic sleeve-pin coupling, which is at the same time the brake pulley of the brake with an electrohydraulic pusher. The drums rotate on an axle fixed in brackets. An open gear is installed on the output shaft of the gearbox, and the gear wheel is also the crown of the drum. The drum is made of threaded with side flanges, the rope is attached to the drum with a steel wedge.

The open gear of the drum is protected by a casing. The boom chain hoist is made sixfold and consists of a movable and a fixed clip. The fixed clip is connected to the axis of the bipedal rack of the portal. The movable clip is suspended from the boom head with the help of cable braces. A deflecting block is installed on the axis of the portal.

The turning mechanism has a bevel-cylindrical gearbox. At the lower end of the vertical output shaft of the gearbox, an open gear is mounted, which engages with the ring gear of the slewing ring. To stop the mechanism, a shoe brake is installed on the drive shaft.

The movement mechanism is made with a separate drive. There are two movement mechanisms installed on the crane, so one of the axles of the undercarriages is the leading one. The movement mechanism is made according to the traditional scheme with a horizontal gearbox.

2. DESIGN CALCULATION OF MECHANISMS

2.1 Calculation of the lifting mechanism

2.1.1 Single drum case

Initial data.

m - maximum carrying capacity, t 25;

H - lifting height, m 14.2;

V - speed of lifting the load, m / min 8.8 (one drum);

(two reels) 17.6;

Operation mode group 4M

The initial data correspond to the operation of a crane with a 15 m long boom with a hook or an electromagnet with plates and blanks. The choice of the scheme of the mechanism for lifting the load and the scheme of the cargo chain hoist has already been made earlier. We accept the installation of the drum with a gear clutch built into it as the most compact and reliable design.

A steel wire rope is taken as a flexible lift of the organ. According to the "Rules for the Construction and Safety of Operation of Hoisting Cranes", the steel rope is selected according to the breaking force:

where S is the maximum tension of the ropes, H;

Z P - safety factor of the rope; Z P \u003d 5.6 5, table 2

The maximum rope tension is determined by formula 2:

where m - load capacity in kt; m \u003d 25t \u003d 25000kt;

block efficiency; \u003d 0.98 - for blocks on rolling bearings;

a is the number of ropes wound on the drum; a=1;

i n - polyspast multiplicity; i n =6 (according to the accepted scheme);

n is the number of guide blocks, n=1.

F = 43904.45.6 = 245864.65 H = 245.864 kN.

Taking into account the possible multilayer winding of ropes on a drum from 1, Table 5.2.3, we select a steel wire rope of a double lay LK-RO 6Ch36 + 1 o.s GOST 7668-80. Rope diameter d = 22.5 mm, breaking force F times = 251 kN with a marking group of 1568 MPa.

We make a geometric calculation of the cargo drum. The drum is carried out as a rifled one with two flanges.

Drum diameter along the center line of the rope coil:

where h 1 - empirical coefficient, is taken depending on the mode group and type of crane; h1=20 5, table 5

D122,520=450 mm.

To reduce the length of the drum, we take its diameter large. The diameter of the drum along the bottom of the groove will be assigned from the normal range of values, i.e. D1o = 630mm. Estimated drum diameter:

D1 \u003d D1o + d k \u003d 630 + 22.5 \u003d 625.5 mm.

The length of the cutting drum when working with a single chain hoist

L b \u003d L 1 + L 2 + L 3, (4)

where L 1 - the length of the threaded part of the drum, mm;

L 2 L 3 - distance from the ends of the drum to the start of cutting, mm.

where n in - the number of turns of the rope laid on the drum;

t - cutting step, mm;

t=dk +23mm=22.5+3=25.5mm;

The coefficient of uneven laying of ropes, = 1.05.

where Z is the number of layers of rope winding on the drum; Z=2 is set.

We accept n in \u003d 20.

L 1 \u003d 2025.51.05 \u003d 535.5 mm

Plot lengths:

L 2 \u003d L 3 \u003d (23) t \u003d 225.5 \u003d 51mm

Full drum length:

L b \u003d 535.5 + 51 + 51 \u003d 637.5 mm

The required engine power of the lifting mechanism is found by formula 2:

where is the overall efficiency of the mechanism, defined as

where m = - efficiency of the transmission mechanism for a two-stage gearbox;

b \u003d 0.96 - efficiency of the drum, for a drum on rolling bearings;

n is the efficiency of the chain hoist.

The overall efficiency of the mechanism: \u003d 0.960.960.933 \u003d 0.86

We select from 1, table 2.1.11 an AC crane motor with a phase rotor MTF 412-6.

Engine power N dv \u003d 43 kW at PV 25%,

shaft speed n engine = 955 rpm

maximum torque T max = 638 Nm,

moment of inertia of the rotor J p \u003d 0.5 kgm 2,

motor shaft end diameter d dv = 65mm.

Gear ratio of the mechanism

where n b - drum rotation frequency, rpm

As a gearbox, we choose a cylindrical two-stage coupled gearbox for the possibility of working with a grab. The gearbox has two input and two output ends of the shaft and is used in KDE-251 railway cranes. The output end of the shaft is made in the form of a gear half-coupling.

To connect the end of the motor shaft and the high-speed shaft of the reducer, an elastic sleeve-pin coupling is used, one of the coupling halves of which is a brake pulley and is installed from the side of the reducer.

By the size of the ends of the connected shafts (mm) from 1, table. 5.2.41 we select a coupling according to OST 24.848.03-79 with a rated torque T k \u003d 2000 Nm, which ensures the connection of the shafts 65h75mm, the diameter of the brake pulley D t \u003d 400mm, the moment of inertia of the clutch, J m \u003d 4.8kgm 2

The selected coupling must satisfy condition 2

T calc T to

where T calc is the calculated value of the moment, Nm.

Torque on motor shaft:

T calc \u003d K 1 T s, (11)

where K 1 \u003d 1.2 - coefficient of the operating mode; for medium duty 2

T calc \u003d 1.2419.1 \u003d 503 Nm

T calc \u003d 503 NmT to \u003d 2000 Nm

The brake is selected according to the braking torque:

T t \u003d T with t, (12)

where \u003d 1.75 braking margin factor; adopted for medium duty 2;

T with t - torque on the motor shaft during braking, Nm

T t \u003d 1.75310 \u003d 542 Nm

According to the diameter of the brake pulley Dт=400mm and the value Тт=542 Nm from 1, Table 5.2.23, we select a two-shoe brake driven by an electro-hydraulic pusher. Brake type: TKG-400, braking torque Tm=1400Nm

We check the electric motor according to the starting conditions:

a) The engine power must be sufficient to ensure the acceleration of the load with a given acceleration that does not exceed the allowable values;

b) During intermittent operation, the engine must not overheat.

The first test condition is written: j j

where j is the calculated acceleration of the load during the start-up period, m/s 2 ;

j \u003d 0.20.6 m / s 2 - permissible value, for general purpose cranes.

where t n is the start time of the load lifting mechanism, s.

where T p.sr is the average starting torque of the electric motor, Nm;

J 1 - the total moment of inertia of the parts installed on the drive shaft of the mechanism, km 2.

J 1 \u003d J p + J m \u003d 0.5 + 4.8 \u003d 5.3 ktm 2;

k=1,11,2 - coefficient taking into account the influence of other rotating parts of the mechanism.

For an AC motor with a phase rotor, the average starting torque

T p.sr \u003d T nom (16)

where T com is the rated torque of the engine, Nm;

The multiplicity of the maximum moment.

T nom \u003d 9550,

Start time:

Launch acceleration:

The test condition is met.

We do not check the electric motor for heating, since the motor power is greater than the calculated value.

2.1.2 Two-drum case

The double-drum scheme of the lifting mechanism provides lifting and lowering of the load not only with one drum, but also with two at the same time. At the same time, each drum is driven from its electric motor with the brake released. The speed of lifting the load when working with two drums simultaneously increases by 2 times, since the chain hoist will now work as a double one and its multiplicity is equal to: j n =.

Lifting speed: V=8.82=17.6m/min.

The calculation of the mechanism consists in checking the suitability of the previously selected elements for the case of working with two drums at the same time, the maximum rope tension from the condition of uniform load distribution between the two drives is found by the formula (2)

In fact, the safety factor of the rope according to the formula (1):

Z P f =6 Z P =5.6 means that the previously selected rope is suitable.

The power required to lift the load by two drives according to the formula (7):

Required power of each of the two engines:

N 1 \u003d N 2 \u003d 0.5N \u003d 0.583.6 \u003d 41.8 kW.

The power of the selected engine: N dv \u003d 43 kW N 1 \u003d N 2 \u003d 41.8 kW.

Since the lifting speed has increased by 2 times, and the multiplicity of the chain hoist has decreased by 2 times, respectively, the value of the required gear ratio of the mechanism, torque and braking torque has not changed.

Therefore, the gearbox, coupling and brake remain the same.

The start time of the mechanism according to the formula (15) at:

Acceleration of the load during the launch period:

The previously selected motor satisfies the start condition.

2.1.3 Grab case

We take the initial data from the technical characteristics of the crane:

grapple weight, t - 1.9;

bulk density of the material, t/m 3 - 1.1;

grab lifting speed, m/min - 53;

grab capacity, m 3 - 1.5

Mass of material in the grab:

m m \u003d V \u003d 1.5 1.1 \u003d 1.65t \u003d 1650 kg.

Total weight of grab with material

m \u003d m gr + m m \u003d 1.9 + 1.65 \u003d 3.55t \u003d 3550 kg.

The ropes are calculated for the case of lifting a loaded grab on the assumption of a uniform distribution of the weight of the grab on the closing and lifting ropes with a safety factor Z P =6.

Estimated force in one rope of two rope grabs:

S = 0.5 mg (17)

S = 0.535509.81 = 17413 H = 17.413 kN.

In fact, the safety factor:

The lifting and closing ropes are taken to be the same in design and diameter.

The total installed capacity of a winch with independent drums when working with a grapple is:

Each of the two engines is selected by power:

N 1 \u003d N 2 \u003d 0.6N \u003d 0.642.898 \u003d 25.74 kW

The power of the previously selected engine: N dv \u003d 43 kWN 1 \u003d N 2 \u003d 25.74 kW, therefore, the engine is suitable.

2.2 Departure change mechanism calculation

The existing scheme of the boom winch is shown in Figure 2.

In the existing design of the winch, a cylindrical gear is mounted on the output shaft of the gearbox, which is in constant engagement with the ring gear 5, which is attached to the drum.

The proposed modernization aims to get rid of the open gear, which in itself is a disadvantage, since it requires constant inspection and control; lubrication of such a transmission by adding grease serves as a constant source of contamination and dusting of the turntable frame. In addition, to improve the performance of the crane, we will reduce the departure change time from 0.62 min to 0.5 min, focusing on similar designs. At the same time, the multiplicity of the boom chain hoist does not change and remains equal to 6.

1-electric motor; 2-coupling connecting; 3-brake; 4 - worm gear; 5-open gear; 6 - rope drum.

Figure 2 - Kinematic diagram of the boom winch:

Since the lifting characteristics of the crane do not change, that is, the lifting capacity is 25 tons at a minimum reach of 4.8 meters, the jib rope remains the same. According to the operating manual, the type of boom rope is the same as that of the cargo winch, that is, LK-RO 6Ch36+1 o.s GOST 7688-80, rope diameter 22.5 mm, breaking force 251 kN, marking group 1568 MPa, mode group work 4M (medium).

We check the suitability of the engine installed in the boom winch at a new speed of change in departure, determined by the formula:

where DL is the change in crane reach when the boom is raised, m;

t=0.5 s - departure change time.

Required engine power, kW:

where z=0.96 - mechanism efficiency;

S MAX - maximum rope tension, N.

For the average operating mode at Z P =5.5 we have according to the formula (1) at F TIME =251 kN:

From 1, table. II.1.11 we select a crane motor MTF 411-6 with a power of 15 kW at a duty cycle of 25%, a shaft speed of 935 rpm, a rotor moment of inertia of 0.225 kg m 2 , a shaft end diameter of 70 mm, and a maximum motor torque of 314 Nm.

The gear ratio of the mechanism is found by the formula (9).

The number of revolutions of the boom drum:

where D B is the diameter of the boom drum, m, we take it equal to 0.5 m.

We choose a cylindrical two-stage gearbox Ts5-500 with a gear ratio of 16, a torque on the low-speed shaft of 17.5 kN m, a diameter of the end of the high-speed shaft of the gearbox is 60 mm, with the execution of the end of the low-speed shaft - a ring gear.

To connect the gearbox shaft with the motor shaft, we provide for the installation of an elastic pin-sleeve coupling with a brake pulley. Torque on the motor shaft, Nm:

The calculated moment of the coupling, with a safety factor K 1 = 1.2, will be equal to:

T R \u003d 1.2 969.32 \u003d 1163.18 Nm.

From we choose with a rated torque of 1000 Nm, which ensures the connection of shafts with a diameter of 50x60 mm, the moment of inertia of the coupling is 1.5 kg m 2, the diameter of the brake pulley is 300 mm.

The calculated braking torque is found by formula (12) with a braking safety factor of 1.5.

Torque on the brake shaft during braking, Nm:

We select the TKG-300 brake with a braking torque of 900 N m, the diameter of the brake pulley is 300 mm.

3. STRENGTH CALCULATIONS

3.1 Calculation of the drum assembly of the load lifting mechanism

We draw up a design diagram of the drum assembly (Figure 3).

Figure 3 - Scheme for calculating the axis of the drum

When the drum is operated with a single chain hoist, the position of the rope is considered alternately under each hub, since when winding onto the drum, the rope moves along the length of the drum.

1 POSITION. The rope is located under the left hub of the drum. The lengths of the sections are taken constructively, focusing on the length of the drum.

Bending moment in the section under the left hub:

2 POSITION. The rope is located above the right hub of the drum.

Bending moment under right hub:

The calculation of the drum axis is reduced to determining the diameters of the trunnions d c and hubs d c from the condition of the axis working for bending in a symmetrical cycle:

where M And - bending moment in the calculated section, Nm;

W And - the moment of resistance of the calculated section in bending, m 3;

Permissible bending stress, MPa, with a symmetrical cycle.

Since the moment of resistance of the section of the axle under the hub is W И = 0.1d c 3, then substituting this expression into formula (19), we first find the diameter of the axle under the hub:

The allowable bending stress in a symmetrical cycle is determined by the formula:

where -1 - endurance limit of the axle material, MPa;

k 0 - coefficient taking into account the design of the part, for shafts and axles is taken 22.8;

n is the allowable safety factor; for the mechanism operation mode group 3m, n = 1.4 is assumed.

Steel 45 s is chosen as the axle material,

We accept k 0 \u003d 2.8.

Axle diameter under the hub:

From the condition of placing the axle bearing inside the bore of the output end of the gearbox, we take d c \u003d 0.115 m. The diameter of the axle pins for the bearing is d c \u003d 90 mm.

Let's make a refined calculation of the axis of the drum. With a dangerous section, the middle section of the axis (between the hubs), the diameter of which is taken:

d \u003d d with -15 mm \u003d 115 - 15 \u003d 100 mm.

Margin of safety in terms of fatigue resistance in the considered section:

where -1 - endurance limit of the axle material for symmetrical bending cycles, MPa;

K b - effective stress concentration factor in bending;

Coefficient taking into account the effect of surface roughness;

Scale factor of normal stresses;

a - amplitude of normal stress cycles, MPa.

The material of the drum axis was previously steel 45, which has β = 600 MPa.

For carbon steel endurance limit:

The value of K = 2.13 for steel shafts with fillets 6, Table 11.2; scale factor E = 0.7 6, Table 11.6 for carbon steel and shaft diameter d = 100 mm.

Amplitude of normal stress cycles according to formula (19)

The strength in the section under consideration is ensured, since the smallest allowable margin of safety for the S axis is 1.6.

To connect the gear half-coupling, made in the form of a flange, we use a pin connection to the drum itself. The material of the bolts is steel 45, with a yield strength of t = 353 MPa.

We install the pins on a circle D env = 300 mm = 0.3 m.

Circumferential shear force acting on the pins:

Permissible pin shear stress:

where t is the yield strength of the pin material;

k 1 =1.3 - safety factor for the lifting mechanism;

k 2 \u003d 1.1 - load factor for the operating mode group 4M 4.

The pin diameter is determined by formula 4:

where R okr - the force acting on the circumference of the installation of pins, N;

m / =0.75m is the estimated number of pins, here m is the number of installed pins (m=68);

Permissible shear stress, Pa.

We accept the number of pins m=6, then m 1 = 0.756 = 4.5.

We select 6 pins 16GCh50 GOST 3128-80.

We carry out the calculation of the drum wall for strength. The main design analysis is the compression analysis, bending and torsion analysis are optional.

As the material of the drum, we take gray cast iron SCH18, the allowable compressive stress of which is compressive = 88.3 MPa.

The wall thickness of the cast iron drum for working with rope 4:

0.02D1+(610mm), (28)

where - D1 is substituted in mm

0.02652.5 + (610mm) = 19.05 23.05 mm

We finally accept = 20mm.

Compressive stresses

compress = 86.087 MPa compressive = 88.3 MPa.

The strength condition is met.

We do not check the drum wall for bending and torsion, since the ratio of the drum length to its diameter L / D1< 34.

We do not calculate the fastening of the end of the rope on the drum, since a steel wedge is used as a clamping device, which is installed in the socket, performed when the drum is cast.

3.2 Selection of bearings

We choose as support bearings ball radial spherical double row 5 according to GOST 5721-75. The number of bearings is 2. Bearing number 3618, inner diameter d = 90 mm, outer diameter D = 140 mm, ring width B = 64 mm. Dynamic load capacity C \u003d 400000 N \u003d 400 kN, static load capacity C 0 \u003d 300000 N \u003d 300 kN. The selected bearing is checked for durability according to 6. Nominal life in hours:

where n is the rotational speed of the bearing ring, rpm;

n \u003d n b \u003d 25.95 rpm;

C - dynamic load capacity, kN;

p - exponent (for roller bearings p = 10/3).

where F r = 194148N = 19.415kN - radial load on the bearing, kN;

V=1 - coefficient of rotation, during the rotation of the inner ring;

K b \u003d 1.31.5 - coefficient of working conditions for cranes 6, table 12.27;

K T \u003d 1.05 - temperature coefficient for the operating temperature of the bearing 125 0 С.

4. ELECTRICAL PART

The cargo winch drum is driven by M13 and M15 engines. Motor control - separate, with the help of controllers S1 and S2, which, with their contacts, turn on the stator and rotor contactors KM9-KM17.

Command controllers have seven fixed positions: three - "Rise"; three - "Descent" and one - neutral.

On the "Rise" stator contactors KM13 and KM14 are switched on, and on the "Descent" - contactors KM110 and KM15. When the load is lowered by the left drum in the dynamic braking mode, the KM9 contactor is turned on.

The rotor circuits of the M13 and M15 engines include ballasts R18 and R19. At the first positions of the controllers, all resistances are introduced into the rotor winding of each motor. When working with loads of more than 3-4 tons and a grab, these positions correspond to the minimum speed for ascent and the maximum for descent. At the third positions of the controllers, resistance is completely removed from the rotor circuits of the electric motors, which corresponds to the maximum speed for ascent and the minimum for descent.

The output from the rotor circuits of the electric motors of the resistance stages is carried out by the acceleration contactors KM11, KM12, KM16 and KM17.

The engine of the left drum M13 has two modes of operation for lowering the load:

Power descent;

Descent in dynamic braking mode.

Switching of modes of operation is made by the package switch SA21 located on the control panel. Switch SA21 must always be in the "Normal descent" position, and only when lowering the load at low speed is required, it is switched to the "Dynamic braking" position.

In this case, the stator winding of the M13 motor is disconnected from the 380V AC network by contactors KM10 and KM13. The contactor KM9 is turned on, and a direct current is supplied to the two phases of the stator winding of the M13 motor through the transformer T4 and the rectifier block of diodes VD18.

The minimum current relay KA8 monitors the presence of current in the stator circuit and, in the event of a sharp decrease in current due to the failure of the fuses FU5 or FU6, turns off the power from the KM8 starter coil, turns off the M12 electro-hydraulic pusher motor, i.e. the drum pulley is braked.

Resistors R20, R21, R22 and switch SA24 are designed for stepwise regulation of the current in the stator winding. Depending on the magnitude of the current, the braking torque of the motor and the speed of lowering the load change.

The electro-hydraulic pusher M1 of the brake is powered through the contacts of the KM8 starter. The KM8 coil is powered through the closing auxiliary contacts of the KM10 or KM13 contactors in the power mode of operation, or through the KM9 and the KA8 relay in the operation mode, or through the KM9 and the KA8 relay in the dynamic braking mode.

In the clamshell mode of operation of the crane, to improve the scooping of bulk cargo, the inclusion of the KM8 starter when the M13 engine is not running is provided by the SA19 pedal.

In the hook mode of operation, the KM8 starter will not turn on from the SA19 pedal, since the contact of the SQ6 limit switch is connected in series with the SA19 pedal, the opening contact of which will be opened when the rope is hooked.

Electrohydraulic pusher M14 of the right drum is connected directly to the stator of the M15 engine and does not have a separate control.

Protection of motors against overcurrent is carried out by relays KA6 and KA7, which turn off the line contactor.

Limit switches SQ7 and SQ11 are introduced to turn off the motors of the cargo winch at the moment when two turns of the rope remain on the drum.

The SQ8 limit switch is designed to limit the lifting height of the lifting device.

In clamshell operation of the crane, when the grab is lowered, in order to avoid loosening of the cables, limit switches SQ6 and SQ124 are installed in hook mode; they are shunted by the package switch SА22. The SA22 switch is installed on the console and has two positions: "Grapple" and "Hook".

Protection of the crane from overloads in terms of load moment is carried out by load moment limiters, the circuit of which includes coils of contactors KM13 and KM14. When the load moment limiters are activated, the cargo winch motors can only work for lowering, and the lifting circuit will be open.

Limit switches SQ9 and SQ10 limit the winding of the rope onto the drum and turn off the motors when the third layer of rope starts to wind onto the drum.

5. SPECIAL PART

5.1 Organization of maintenance

During the operation of the crane, there is a loss of its performance and the destruction of its individual parts. In order to maintain the quality indicators provided for by the regulatory documentation at the appropriate level, and to ensure the crane's trouble-free operation, a set of interrelated provisions, norms and preventive measures is provided, which are included in the system of maintenance and repair of equipment.

The essence of the system is that after the crane has worked a certain number of hours, maintenance and repairs are carried out.

Crane maintenance includes the following types of work: shift maintenance, maintenance No. 1 (TO-1), maintenance No. 2 (TO-2), and maintenance No. 3 (TO-3). Maintenance is carried out at the intervals and to the extent specified in this manual, regardless of the technical condition of the crane at the time of maintenance.

daily maintenance;

maintenance No. 1 - after 100 hours of work;

maintenance No. 2 - after 600 hours. work;

maintenance No. 3 - after 3000 hours. work;

When carrying out maintenance and repairs of cranes, it is necessary to strictly comply with the basic requirements of safety, labor protection and fire safety.

All maintenance work is assigned to the drivers: cleaning, lubricating, fixing, adjusting, and eliminating minor malfunctions.

The admission of machinists to the maintenance and repair of the electrical equipment of the crane can be carried out only with the permission of the chief power engineer of the enterprise in the manner prescribed by the “Rules technical operation electrical installations of consumers”;

Some limited maintenance work is assigned to the machinists: cleaning part of the lubrication. The rest of the work - on changing the lubricant in gearboxes, fastening, adjusting and troubleshooting mechanisms - is assigned to locksmiths and electricians;

The machinists are not responsible for maintenance, and all maintenance is carried out by locksmiths and electricians.

The possibility of using each of the above schemes is determined by the operating conditions of the crane and, in particular, its loading in time.

For the correct maintenance of cranes, the administration of the enterprise is obliged to provide the maintenance personnel with instructions that define their rights and obligations.

Before starting work, the crane operator must perform daily maintenance of the crane, for which the administration of the enterprise must allocate appropriate time.

Maintenance of cranes should be based on a planned preventive system, i.e. after a certain number of hours, the crane without fail, regardless of its technical condition, must be inspected, tested, adjusted with the elimination of noticed malfunctions.

When carrying out maintenance of the crane, it is necessary to use this operation manual, the instruction manual for the diesel generator set, the instruction for installation and operation of the ECC series synchronous generators and other instructions supplied with the crane.

When carrying out daily maintenance, you must:

Perform an external inspection of the mechanisms and components of the crane in order to check the absence of visible damage. Subject to inspection: running platform, swivel frame, running carts, travel mechanisms, safety devices for travel mechanisms, automatic coupler, swing mechanism, cargo and boom winches, boom, portal, outriggers, power point, Remote Control.

Check the lubricant level in the gearboxes, make sure there are no leaks. If the lubricant level falls below the permissible level, top up with lubricant. Take measures to eliminate leakage.

Carry out work on the daily maintenance of the diesel generator in accordance with the operating instructions for the diesel engine.

Check the condition of the ropes and barriers of the blocks, make sure that there are no unacceptable damages, the correct location of the ropes in the streams of the blocks.

Check the wedge fastenings of the ropes on the boom head and at the movable traverse of the boom chain hoist in order to check the absence of visible damage on the wedge bushings and the presence of clamps at the ends of the rope.

For further maintenance, start the diesel generator.

Make sure that the instrumentation, lighting and signaling are in good condition by inspecting or turning them on one by one.

Check the crane at idle by switching on and braking all mechanisms in turn.

Make sure the safety devices are working:

Hook lifting height limiter - by lifting the hook clip until the limiter is activated and the cargo winch is turned off for lifting;

The limiter for the minimum number of turns on the drum of the cargo winch - by setting the boom to the minimum reach and lowering the hook until the limiter is activated and the cargo winch is turned off for lowering (at least one and a half turns of the rope must remain on the drum);

Load limiter - by checking the presence of a seal on the limiter;

Load indicator and fire extinguisher - visually.

When carrying out maintenance No. 1 (TO-1), it is necessary to carry out shift maintenance work and, in addition:

Carry out maintenance work No. 1 of the diesel generator in accordance with the diesel operating instructions.

Carry out work on the care of batteries according to the instructions.

Inspect the undercarriage, spring suspension, axle boxes, wheel sets, check the condition of the undercarriage platform, the correct suspension of the frames of the movement mechanism on articulated rods.

Check the fastening of the diesel generator, electrical appliances, panels, resistances, fuel tank, removable counterweight.

Make sure that there is no visible damage to the metal structure of the portal, the movable and fixed traverse-boom chain hoist.

Check the tightness of the turntable bolts. The bolts connecting the turntable to the running and turning frames must be tightened with a force that creates a moment of 115-125 kgcm.

Check the fastening of the gearbox of the mechanisms of movement, rotation, lifting winch, the fastening of the electric motors of these mechanisms to the frames.

Check the fastening and correct adjustment of the electro-hydraulic brakes of the cargo and boom winches, travel and turning mechanisms.

Check the condition of the current collector, the stabilizing device of the generator, clean the slip rings of the rotor from brush dust, tighten loose contact connections.

Lubricate according to the lubrication table.

Check the oil level in the outrigger hydraulic tank and top up if necessary.

Eliminate faults identified during maintenance.

When carrying out maintenance No. 2 (TO-2), it is necessary to carry out maintenance work No. 1 and, in addition:

Carry out maintenance work No. 2 of the diesel generator in accordance with the diesel operating instructions.

Inspect gearboxes through inspection hatches. Gearings must work with the entire surface (the minimum contact patch is allowed 40% in height 50% in length). Check the alignment of the couplings of the mechanisms.

Check the adjustment of the brakes of the mechanisms, add oil to the hydraulic pushers.

Inspect all elements of the metal structure, paying special attention to the condition of the welds of the boom, portal, welding of the frames of the mechanisms to the swing frame, for the absence of cracks and residual deformations.

Inspect the condition of the blocks, guide rollers, boom and cargo ropes, stretch marks, wedge fastenings of the ropes.

Inspect interchangeable boom equipment.

Change the oil in all gearboxes.

Eliminate faults identified during maintenance.

When carrying out maintenance No. 3 (TO-3), it is necessary to carry out maintenance work No. 2 and, in addition:

Carry out maintenance work No. 3 of the diesel generator in accordance with the diesel operating instructions.

Carry out maintenance work on the running platform: inspect outriggers, automatic couplers, rail grippers, spring switches, auto-brake equipment; clean the running platform from dirt and check the frame beams for cracks, paying special attention to the spinal, pivot, longitudinal and central, attachment points of the outriggers and the turntable.

Carry out maintenance work on the swing frame; clean the swivel frame from dirt and oil and check the frame beams for cracks, paying special attention to the main beams, the beam with lugs for attaching the boom, the attachment points of the portal support boom, the turntable, the welding of the mechanism frames.

Carry out maintenance work on the turntable; inspect, replace broken bolts and fix loose ones, adjust the gap between the rings.

Carry out maintenance work on the outriggers: inspect the hydraulic system of the outriggers, eliminate leaks, check the cleanliness of the oil in the hydraulic system and, if necessary, replace.

Carry out maintenance work on the cargo and boom winches: inspect all bearings and seals of the gearbox with the cover removed, inspect the drums and their guards, the pressure roller of the cargo drum, replace worn-out brake linings.

Carry out maintenance work on the turning mechanism: inspect all bearings and seals of the gearbox with the cover removed, inspect the open gear transmission (connection of the mechanism to the turntable), replace brake linings that are worn out beyond the norm.

Carry out maintenance work on the movement mechanisms: inspect all bearings and seals of the gearboxes with the covers removed, as well as the axle bearing, replace brake linings that are worn out beyond the norm, check the integrity of the suspension of the frames on the articulated rods, clean the wheel pairs from dirt and check the profile of the wheels.

Carry out maintenance work on the gantry and load limiter: check the condition of the gantry structures, lugs, portal axis, fixed traverse; check the condition of the load limiter cam, torsion shaft, adjusting screws and levers, microswitches, traction; check the correct adjustment of the load limiter.

Carry out maintenance work on the crane body: inspect and repair the locks of doors and opening doors of the body, check the sealing of hatches, braces and braces of the portal.

Carry out maintenance work on the hook block: inspect the hook thrust bearing, traverse and hook, paying special attention to the transition point of the threaded part of the shank to smooth and wear of the hook bearing surface.

Carry out counterweight maintenance work: inspect and tighten loose counterweight mounting bolts.

Carry out maintenance work on the crane boom: inspect the boom head, the attachment points of the boom to the swing frame, the grab damper, the rope loosening limiter, the joints of the boom sections.

Carry out maintenance work on the driver's cab: inspect the control panel, paying special attention to the control levers and their secure fixation in extreme and intermediate positions, check all limiters and interlocks.

Carry out maintenance work on electrical equipment in accordance with the instructions of subsection 6.8. this manual.

5.2 Repair of cranes

Repair of cranes is carried out in a planned manner, depending on their technical condition. Unscheduled repairs are caused by a crane failure, and this type of repair is not included in the annual repair plans.

Repair of cranes is divided into current, medium and capital.

During current repairs, by replacing or restoring worn parts and adjusting mechanisms, they ensure or restore the crane's performance.

Medium repair is performed to restore the resource of the crane; at this time, partial disassembly of the crane, major repairs of individual small assembly units, replacement and restoration of the main worn parts are carried out.

Overhaul is carried out to restore serviceability and complete or close to complete restoration of the crane resource. The repair includes the complete development of the crane, the replacement of all worn assembly units and parts, including the base ones.

Based on the operating experience of diesel-electric cranes, the following types of scheduled repairs and approximate dates for their implementation have been established.

The current repair is carried out as the malfunctions discovered during maintenance are identified, and, as a rule, is combined with maintenance No. 3.

The average repair is carried out after 13,000 hours of operation. During a medium repair, an audit of the slewing device, all gearboxes is carried out with the replacement, if necessary, of gear elements, bearings, replacement of blocks, drums, ropes, and welding of the metal structures of frames and booms.

Major repairs are carried out after 26,000 hours of operation. At the same time, the repair of the chassis and swivel frames is carried out, technical documentation. When changing the working fluid, oil should be poured through a metal mesh to prevent foreign impurities from entering the pusher chamber.

The hydraulic pusher is filled with oil in the vertical position of the hydraulic pusher body. In this case, it is necessary to ensure the removal of air from under the piston and from the electric motor. To do this, 5 minutes after filling the hydraulic pusher with oil to the upper level, the hydraulic pusher is turned on 10 times. These inclusions will speed up the removal of air from the oil. When filling oil into electric hydraulic pushers, the level must be strictly observed. Oil must be filled until it appears in the filler tube. Overfilling with oil can cause overpressure in operation which can destroy the terminal block. If there is less than normal oil, the pusher may work in an unstable mode or will not work at all.

Before the first start-up of pushers filled with transformer oil at a temperature of -10 ° C and below with PES 3D liquid at a temperature of -40 ° C, it is necessary to warm up the pusher by several short-term switching on. Duration of switching on 10 -20 with an interval of 1-2 minutes.

More detailed instructions on maintenance, possible malfunctions and methods for their elimination, repair of brakes with electro-hydraulic pushers are given in the brake data sheets attached to the crane documentation.

During operation, irregularities form on the friction surface of the brake pulley rim.

With a depth of roughness of more than 0.5 mm, the surface must be re-sharpened. The amount of regrinding is allowed no more than 30 of the initial thickness of the rim. After turning, the surface of the pulley must be heat treated to the desired hardness.

The working surface of the pulley can also be restored by vibrating blown or manual surfacing, followed by turning and heat treatment.

The brake pulleys are not allowed to run out as a result of uneven wear, more than 0.002 of the pulley diameter, as well as cracks and loose fit on the shafts or loose fit of the keys.

For brake springs, cracks, broken coils, and permanent deformation are signs of rejection.

In the pivot joints of the levers, wear of more than 5% of the original diameter and ovality of more than 0.5 mm, as well as the presence of cracks in the levers, are not allowed. The worn holes of the eyelets of the levers are repaired by reaming to a new (larger) repair size, and the rollers are made with a corresponding increased diameter. The maximum increase in diameter is 7-10% of the initial one. It is advisable to increase the wear resistance of the rollers by chemical-thermal treatment to a hardness of HRC 54-62, as well as to press heat-treated bushings with a high hardness of the working surface into the holes of the levers.

When repairing and replacing brakes, the following requirements for installing a brake must be observed

The diameter of the brake pulley must not exceed 300 mm (-0.32) for the TG-300 brake and 200 mm (-0.29 mm) for the TG-200 brake. Runout, taper and ovality of the working surface of the pulley are not allowed more than 0.05 mm. The working surface of the pulley must have a hardness HB of at least 280 and a roughness of at least 1.25 according to GOST 2308-79;

during installation, the center of the brake must coincide with the center of the pulley (permissible deviation should not exceed 1 mm);

non-parallelism of the pads relative to the surface of the pulley should not exceed 0.3 mm per 100 mm of the pad width;

in the pusher motor, check the insulation resistance of the winding relative to the housing, make sure that there is no possible phase failure. The lowest allowable cold insulation resistance must be at least 20 MΩ. With a lower insulation resistance, the stator winding should be dried. During drying, the winding temperature should not exceed 70°C.

5.3 Rope maintenance

Rope maintenance includes cleaning, visual inspection, lubrication and inspection of the rope attachment.

The ropes are cleaned manually using metal brushes or by passing at a speed of 0.25-0.4 m / s through the wrench with dies, the inner surface of which in diameter and shape corresponds to the surface of the rope. Other designs may also be used.

An external inspection to check the condition of the rope is carried out after it has been cleaned. The rope must be inspected along its entire length. With special care, the areas of the most probable wear and destruction of the wires (areas wound on the drum and bent on blocks) are examined. The condition of the rope is assessed by the number of broken wires, their degree of wear and breakage of the strands.

The rejection rates for steel ropes are regulated by the Rules for the Construction and Safe Operation of Cranes.