CN221317946U - Heavy platform type assembly line - Google Patents

Abstract

The application provides a heavy platform type assembly line, wherein a driving sprocket assembly comprises an assembly base, a bearing seat, a small sprocket flange, a large sprocket and a large sprocket flange; the lower tapered roller bearing, the upper tapered roller bearing and the cylindrical roller bearing are sleeved in the bearing seat in sequence, and the rotating shaft is inserted into the three bearings; the rotating shaft passes through three spacers, wherein the first spacer is positioned between the upper tapered roller bearing and the cylindrical roller bearing, the first spacer is close to the outer diameter surface of the rotating shaft, the third spacer is positioned between the upper tapered roller bearing and the cylindrical roller bearing, the third spacer is close to the inner diameter surface of the bearing seat, the second spacer is positioned between the upper tapered roller bearing and the lower tapered roller bearing, and the second spacer is close to the inner diameter surface of the bearing seat; the structure of the driving chain wheel assembly is more complex, more perfect, more comprehensive and complete and more reasonable in stress, so that the stability of the driving chain wheel assembly is improved, and the transmission reliability is improved.

Description

Heavy platform type assembly line

Technical Field

The utility model relates to the technical field of heavy platform type assembly lines, in particular to a heavy platform type assembly line.

Background

The heavy platform type assembly line (heavy double-sided overhead rotary assembly line) consists of a closed annular rotary line, a plurality of wire harness workbench trolleys which are equidistantly arranged at intervals and run on an overhead platform, a transmission system, a PLC electrical control system and the like. The annular rotary line consists of two straight rails, arc rails with semicircular ends and a support for supporting the rails, the workbench is obliquely fixed on the operation trolleys, the operation trolleys are arranged on the production line in a head-to-tail mode, and the operation trolleys on the production line are driven by a conveying chain after speed regulation by a frequency converter to walk on the platform according to the line speed set by a process.

However, there are a number of problems in practical use, and improvement is urgently needed, and specific problems are as follows:

(1.1) the drive sprocket assembly is simple in structure, resulting in insufficient reliability of transmission;

(2.1) the electric box is directly fixed on the square pipe rack by screws and nuts, so that the height cannot be adjusted;

(3.1) the rotation mode of the workbench is horizontal axis rotation, when the tooling plate is too large and heavy, danger is easy to occur during overturning due to factors such as gravity and inertia;

(3.2) the length of the trolley is the same as that of the workbench, so that the weight is large, and the cost materials are wasted;

And (3.3) the workbench adopts a square tube welding mode, so that the workbench has large self weight and labor are wasted in manual rotation.

Disclosure of utility model

The utility model aims to provide a heavy platform type assembly line.

In order to solve the technical problems, the technical scheme provided by the utility model is as follows:

A heavy platform type assembly line comprises a driving sprocket assembly, wherein the driving sprocket assembly comprises an assembly base, a bearing seat, a rotating shaft, a lower tapered roller bearing, an upper tapered roller bearing, a cylindrical roller bearing, a first spacer, a second spacer, a third spacer, a small sprocket flange, a large sprocket and a large sprocket flange;

The bearing seat is of a cylindrical structure and is fixedly arranged on the assembly base;

The lower tapered roller bearing, the upper tapered roller bearing and the cylindrical roller bearing are sleeved in the bearing seat in sequence from bottom to top, the rotating shaft is inserted and sleeved in an inner ring of the lower tapered roller bearing, an inner ring of the upper tapered roller bearing and an inner ring of the cylindrical roller bearing, and the lower tapered roller bearing and the upper tapered roller bearing are reversely arranged;

the rotating shaft passes through the first spacer bush, the second spacer bush and the third spacer bush, the first spacer bush is positioned in a gap between the upper tapered roller bearing and the cylindrical roller bearing, the first spacer bush is sleeved on the outer diameter surface close to the rotating shaft, the third spacer bush is positioned in a gap between the upper tapered roller bearing and the cylindrical roller bearing, the third spacer bush is sleeved on the inner diameter surface close to the bearing seat, the second spacer bush is positioned in a gap between the upper tapered roller bearing and the lower tapered roller bearing, and the second spacer bush is sleeved on the inner diameter surface close to the bearing seat;

A dust-proof pad is arranged at the top opening of the bearing seat;

The small sprocket wheel flange is welded and sleeved on the outer diameter surface of the top of the rotating shaft, the small sprocket wheel is installed on the small sprocket wheel flange through bolt connection, the large sprocket wheel flange is installed on the large sprocket wheel flange through bolt connection, the large sprocket wheel flange is located above the small sprocket wheel flange, the large sprocket wheel is located above the small sprocket wheel, the inner diameter of the small sprocket wheel is larger than the outer diameter of the large sprocket wheel flange, and a chain spacer is sleeved between the inner diameter surface of the small sprocket wheel and the outer diameter surface of the rotating shaft.

Preferably, the electric cabinet assembly comprises a support frame, an electric cabinet, a motor, a ball screw, two vertical linear guide rails and four sliding blocks;

The motor is fixedly arranged on the support frame;

the upper end seat and the lower end seat of the ball screw are fixedly arranged on the support frame, and an output shaft of the motor is in transmission connection with the upper end of the screw in the ball screw;

The two vertical linear guide rails are parallel to each other and are arranged on the support frame, each vertical linear guide rail is provided with two sliding blocks, and each sliding block slides on the vertical linear guide rail to form a sliding pair;

The nut seat in the ball screw is connected with the inner side wall bolt of the electric cabinet, and each sliding block is connected with the inner side wall bolt of the electric cabinet, so that the positive and negative rotation of the output shaft of the motor drives the screw rod to rotate so as to drive the nut seat to lift up and down, and the nut seat drives the electric cabinet to lift up and down.

Preferably, the device further comprises a trolley assembly, wherein the trolley assembly comprises a trolley, a workbench and a vertical rotating component;

the workbench is of a rectangular frame type structure, and the trolley is of a flat car type structure;

The vertical rotating assembly comprises a central shaft, a central shaft seat, a vertical shaft, a thrust ball bearing and an outer spherical ball bearing of a jackscrew with a square seat;

the axis of the central shaft and the axis of the vertical shaft are perpendicular to the object carrying plane of the trolley;

The central shaft seat is welded and fixed on the trolley, the bottom of the central shaft is inserted and fixed in a central hole in the central shaft seat, and the top of the central shaft passes through a through hole in a bottom plate of the workbench;

The seat ring of the thrust ball bearing is sleeved on the outer diameter surface of the circular convex ring in the central shaft seat, the shaft ring of the thrust ball bearing is sleeved on the outer diameter surface of the central shaft, and the bottom flat plate of the workbench is overlapped and placed on the shaft ring in the thrust ball bearing;

The outer spherical ball bearing is overlapped on the upper long and wide surface of the bottom plate of the workbench, the inner ring of the outer spherical ball bearing is sleeved on the outer diameter surface of the central shaft, and the square seat in the outer spherical ball bearing is connected with the bottom plate of the workbench through bolts;

The lower flange plate is fixedly arranged on the top end surface of the central shaft through countersunk bolts;

An upper flange plate is welded at the bottom end of the vertical shaft and is superposed on the lower flange plate, and the upper flange plate and the lower flange plate form a bolt connection through bolts;

The top end of the vertical shaft is fixedly connected with the top beam of the workbench through a hoop;

the trolley is fixed, and the workbench rotates along a vertical axis through the thrust ball bearing and the outer spherical ball bearing.

Preferably, the outer diameter surface of the thrust ball bearing is sleeved with a protective sleeve.

Preferably, the length of the trolley is 1/3-1/2 of the length of the workbench.

Preferably, the workbench with the rectangular frame-type structure is formed by splicing and assembling aluminum profiles.

The application has the following beneficial technical effects:

In the application, the structure of the driving chain wheel assembly is more complex, more perfect, more comprehensive and complete and the stress is more reasonable, thereby improving the stability of the driving chain wheel assembly and the reliability of transmission.

In the application, (2.1) the height adjustment of the electric appliance box adopts ball screw transmission, the electric appliance box is fixed with the ball screw seat, the ball screw is driven by a motor, and the sliding block is supported in an auxiliary way, so that the electric appliance box is driven to move up and down, and the height adjustment is free, convenient and quick.

In the application, the trolley is fixed by arranging the vertical rotating component, the workbench rotates along the vertical shaft through the thrust ball bearing and the outer spherical ball bearing, the rotating mode of the workbench is that the workbench rotates along the vertical shaft, compared with the traditional workbench which rotates along the horizontal shaft, the vertical shaft has better supporting function when rotating, and the vertical shaft rotating structure reduces the influence of factors such as gravity, inertia and the like, so that the rotating safety coefficient is higher, more convenient, more stable and quicker.

In the application, the length of the trolley is 1/3-1/2 of the length of the workbench, the length of the trolley is shortened to 2400mm, the workbench with the bearing length of 5500mm or more can be ensured, the portability is realized, and the cost materials are reduced.

In the application, the workbench is formed by splicing and assembling aluminum profiles, so that the stability and the safety are ensured, the self weight is reduced, and the operation and the movement are convenient.

Drawings

FIG. 1 is a schematic side view of a heavy duty platform assembly line according to an embodiment of the present application;

FIG. 2 is a schematic perspective view of a driving sprocket assembly in a heavy-duty platform assembly line according to an embodiment of the present application;

FIG. 3 is a schematic cross-sectional structural view of the drive sprocket assembly of FIG. 2;

fig. 4 is a schematic perspective view of an electric cabinet assembly in a heavy platform assembly line according to an embodiment of the present application;

FIG. 5 is a schematic left-hand view of the electric cabinet assembly of FIG. 4;

Fig. 6 is a schematic perspective view of a trolley assembly in a heavy platform assembly line according to an embodiment of the present application;

FIG. 7 is a schematic front view of the trolley assembly of FIG. 6;

FIG. 8 is an enlarged right-hand schematic view of the trolley assembly of FIG. 6;

FIG. 9 is a schematic view of the vertical rotation assembly of FIG. 6;

In the figure: 1 trolley, 2 working table;

301 central shaft, 302 central shaft seat, 303 vertical shaft, 304 thrust ball bearing, 305 outer spherical ball bearing with square seat jackscrew, 306 bottom plate of workbench, 307 lower flange, 308 upper flange, 309 protective sleeve;

401 assembly base, 402 bearing seat, 403 rotating shaft, 404 lower tapered roller bearing, 405 upper tapered roller bearing, 406 cylindrical roller bearing, 407 spacer I, 408 spacer II, 409 spacer III, 410 dustproof pad, 411 small sprocket, 412 small sprocket flange, 413 large sprocket, 414 large sprocket flange, 415 chain spacer;

501 supporting frame, 502 electric cabinet, 503 motor, 504 screw in ball screw, 505 nut seat in ball screw, 506 vertical linear guide rail, 507 slider.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center", "axial", "radial", "longitudinal", "transverse", "length", "width", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "high", "low", "clockwise", "counterclockwise", "inside", "outside", "horizontal", "vertical", etc. indicate orientations or positional relationships are based on the orientations or positional relationships during actual use, and the worker stands for "front" in working position only for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Referring to fig. 1-9, in which: a trolley 1 and a workbench 2; central shaft 301, central shaft seat 302, vertical shaft 303, thrust ball bearing 304, outer spherical ball bearing 305 with square seat jackscrew, bottom plate 306 of workbench 2, lower flange 307, upper flange 308, protective sleeve 309; the assembly comprises an assembly base 401, a bearing seat 402, a rotating shaft 403, a lower tapered roller bearing 404, an upper tapered roller bearing 405, a cylindrical roller bearing 406, a first spacer 407, a second spacer 408, a third spacer 409, a dustproof pad 410, a small sprocket 411, a small sprocket flange 412, a large sprocket 413, a large sprocket flange 414 and a chain spacer 415; the device comprises a support frame 501, an electric cabinet 502, a motor 503, a screw rod 504 in a ball screw, a nut seat 505 in the ball screw, a vertical linear guide 506 and a sliding block 507.

The application provides a heavy platform type assembly line, which comprises a driving sprocket assembly, wherein the driving sprocket assembly comprises an assembly base 401, a bearing seat 402, a rotating shaft 403, a lower tapered roller bearing 404, an upper tapered roller bearing 405, a cylindrical roller bearing 406, a first spacer 407, a second spacer 408, a third spacer 409, a small sprocket 411, a small sprocket flange 412, a large sprocket 413 and a large sprocket flange 414;

the bearing seat 402 is of a cylindrical structure, and the bearing seat 402 is fixedly arranged on the assembly base 401;

The lower tapered roller bearing 404, the upper tapered roller bearing 405 and the cylindrical roller bearing 406 are sleeved in the bearing seat 402 in sequence from bottom to top, the rotating shaft 403 is sleeved in the inner ring of the lower tapered roller bearing 404, the inner ring of the upper tapered roller bearing 405 and the inner ring of the cylindrical roller bearing 406 in an inserted manner, and the lower tapered roller bearing 404 and the upper tapered roller bearing 405 are reversely arranged;

The rotating shaft 403 passes through a first spacer 407, a second spacer 408 and a third spacer 409, wherein the first spacer 407 is positioned in a gap between the upper tapered roller bearing 405 and the cylindrical roller bearing 406, the first spacer 407 is sleeved on the outer diameter surface close to the rotating shaft 403, the third spacer 409 is positioned in a gap between the upper tapered roller bearing 405 and the cylindrical roller bearing 406, the third spacer 409 is sleeved on the inner diameter surface close to the bearing seat 402, the second spacer 408 is positioned in a gap between the upper tapered roller bearing 405 and the lower tapered roller bearing 404, and the second spacer 408 is sleeved on the inner diameter surface close to the bearing seat 402;

a dust pad 410 is arranged at the top opening of the bearing seat 402;

The small sprocket wheel flange 412 is welded and sleeved on the outer diameter surface of the top of the rotating shaft 403, the small sprocket wheel 411 is installed on the small sprocket wheel flange 412 through bolt connection, the large sprocket wheel flange 414 is welded and sleeved on the outer diameter surface of the top of the rotating shaft 403, the large sprocket wheel 413 is installed on the large sprocket wheel flange 414 through bolt connection, the large sprocket wheel flange 414 is located above the small sprocket wheel flange 412, the large sprocket wheel 413 is located above the small sprocket wheel 411, the inner diameter of the small sprocket wheel 411 is larger than the outer diameter of the large sprocket wheel flange 414, and a chain spacer 415 is sleeved between the inner diameter surface of the small sprocket wheel 411 and the outer diameter surface of the rotating shaft 403.

In one embodiment of the application, the heavy platform type assembly line further comprises an electric cabinet assembly, wherein the electric cabinet assembly comprises a support frame 501, an electric cabinet 502, a motor 503, a ball screw, two vertical linear guide rails 506 and four sliding blocks 507;

the motor 503 is fixedly arranged on the supporting frame 501;

The upper end seat and the lower end seat of the ball screw are fixedly arranged on the supporting frame 501, and the output shaft of the motor 503 is in transmission connection with the upper end of the screw 504 in the ball screw;

The two vertical linear guide rails 506 are parallel to each other and are arranged on the support frame 501, each vertical linear guide rail 506 is provided with two sliding blocks 507, and each sliding block 507 slides on the vertical linear guide rail 506 to form a sliding pair;

The nut seat 505 in the ball screw is connected with the inner side wall bolt of the electric cabinet 502, and each sliding block 507 is connected with the inner side wall bolt of the electric cabinet 502, so that the positive and negative rotation of the output shaft of the motor 503 drives the screw rod 504 to rotate so as to drive the nut seat 505 to lift up and down, and the nut seat 505 drives the electric cabinet 502 to lift up and down.

In one embodiment of the application, a heavy duty platform assembly line further comprises a trolley assembly comprising a trolley 1, a workbench 2 and a vertical rotation component;

the workbench 2 is of a rectangular frame type structure, and the trolley 1 is of a flat car type structure;

The vertical rotating assembly comprises a central shaft 301, a central shaft seat 302, a vertical shaft 303, a thrust ball bearing 304 and an outer spherical ball bearing 305 of a jackscrew with a square seat;

The axis of the central shaft 301 and the axis of the vertical shaft 303 are perpendicular to the object carrying plane of the trolley 1;

The central shaft seat 302 is welded and fixed on the trolley 1, the bottom of the central shaft 301 is inserted and fixed in a central hole in the central shaft seat 302, and the top of the central shaft 301 passes through a through hole in a bottom flat plate 306 of the workbench 2;

The seat ring of the thrust ball bearing 304 is sleeved on the outer diameter surface of the circular convex ring in the central shaft seat 302, the shaft ring of the thrust ball bearing 304 is sleeved on the outer diameter surface of the central shaft 301, and the bottom flat plate 306 of the workbench 2 is overlapped and placed on the shaft ring in the thrust ball bearing 304;

the outer spherical ball bearing 305 is overlapped and placed on the upper long and wide surface of the bottom flat plate 306 of the workbench 2, the inner ring of the outer spherical ball bearing 305 is sleeved on the outer diameter surface of the central shaft 301, and a square seat in the outer spherical ball bearing 305 is connected with the bottom flat plate 306 of the workbench 2 through bolts;

The lower flange 307 is fixed on the top end surface of the central shaft 301 through countersunk bolts;

An upper flange plate 308 is welded on the bottom end of the vertical shaft 303, the upper flange plate 308 is superposed on the lower flange plate 307, and the upper flange plate 308 and the lower flange plate 307 form a bolt connection through bolts;

the top end of the vertical shaft 303 is fixedly connected with the top beam of the workbench 2 through a hoop;

The carriage 1 is immobilized, the central shaft 301 rotates with the vertical shaft 303, and the table 2 rotates along the vertical shaft 303 with the outer spherical ball bearing 305 through the thrust ball bearing 304.

In one embodiment of the application, the outer diameter surface of thrust ball bearing 304 is sleeved with a protective sleeve 309.

In one embodiment of the application, the length of the trolley 1 is 1/3-1/2 of the length of the table 2.

In one embodiment of the application, the workbench 2 of rectangular frame type structure is made of aluminum profiles assembled in a spliced manner.

In the application, the thrust ball bearing 304 consists of three parts, namely a seat ring, a shaft ring and a steel ball retainer assembly, wherein the shaft ring is matched with a shaft, the seat ring is matched with a shell, and can bear axial load but cannot bear radial load.

In the present application, the outer spherical ball bearing 305 is a modification of the deep groove ball bearing, and is characterized in that the outer diameter surface of the outer ring is spherical, and can be matched into the corresponding concave spherical surface of the bearing seat 402 to play a role of aligning, and the outer spherical ball bearing is mainly used for bearing radial and axial combined loads mainly based on radial loads, and is generally not suitable for bearing axial loads independently.

In the present application, the small sprocket 411 is a 70-tooth sprocket, and the large sprocket 413 is a 100-tooth sprocket.

The method and the device which are not described in detail in the utility model are all the prior art and are not described in detail.

The principles and embodiments of the present utility model have been described herein with reference to specific examples, which are intended to be merely illustrative of the methods of the present utility model and their core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the utility model can be made without departing from the principles of the utility model and these modifications and adaptations are intended to be within the scope of the utility model as defined in the following claims.

Claims (6)

1. The heavy platform type assembly line comprises a driving sprocket assembly and is characterized in that the driving sprocket assembly comprises an assembly base, a bearing seat, a rotating shaft, a lower tapered roller bearing, an upper tapered roller bearing, a cylindrical roller bearing, a first spacer bush, a second spacer bush, a third spacer bush, a small sprocket flange, a large sprocket and a large sprocket flange;

The bearing seat is of a cylindrical structure and is fixedly arranged on the assembly base;

The lower tapered roller bearing, the upper tapered roller bearing and the cylindrical roller bearing are sleeved in the bearing seat in sequence from bottom to top, the rotating shaft is inserted and sleeved in an inner ring of the lower tapered roller bearing, an inner ring of the upper tapered roller bearing and an inner ring of the cylindrical roller bearing, and the lower tapered roller bearing and the upper tapered roller bearing are reversely arranged;

the rotating shaft passes through the first spacer bush, the second spacer bush and the third spacer bush, the first spacer bush is positioned in a gap between the upper tapered roller bearing and the cylindrical roller bearing, the first spacer bush is sleeved on the outer diameter surface close to the rotating shaft, the third spacer bush is positioned in a gap between the upper tapered roller bearing and the cylindrical roller bearing, the third spacer bush is sleeved on the inner diameter surface close to the bearing seat, the second spacer bush is positioned in a gap between the upper tapered roller bearing and the lower tapered roller bearing, and the second spacer bush is sleeved on the inner diameter surface close to the bearing seat;

A dust-proof pad is arranged at the top opening of the bearing seat;

The small sprocket wheel flange is welded and sleeved on the outer diameter surface of the top of the rotating shaft, the small sprocket wheel is installed on the small sprocket wheel flange through bolt connection, the large sprocket wheel flange is installed on the large sprocket wheel flange through bolt connection, the large sprocket wheel flange is located above the small sprocket wheel flange, the large sprocket wheel is located above the small sprocket wheel, the inner diameter of the small sprocket wheel is larger than the outer diameter of the large sprocket wheel flange, and a chain spacer is sleeved between the inner diameter surface of the small sprocket wheel and the outer diameter surface of the rotating shaft.

2. The heavy duty platform assembly line of claim 1, further comprising an electric cabinet assembly comprising a support frame, an electric cabinet, a motor, a ball screw, two vertical linear guides, four slides;

The motor is fixedly arranged on the support frame;

the upper end seat and the lower end seat of the ball screw are fixedly arranged on the support frame, and an output shaft of the motor is in transmission connection with the upper end of the screw in the ball screw;

The two vertical linear guide rails are parallel to each other and are arranged on the support frame, each vertical linear guide rail is provided with two sliding blocks, and each sliding block slides on the vertical linear guide rail to form a sliding pair;

The nut seat in the ball screw is connected with the inner side wall bolt of the electric cabinet, and each sliding block is connected with the inner side wall bolt of the electric cabinet, so that the positive and negative rotation of the output shaft of the motor drives the screw rod to rotate so as to drive the nut seat to lift up and down, and the nut seat drives the electric cabinet to lift up and down.

3. The heavy duty platform assembly line of claim 1, further comprising a trolley assembly comprising a trolley, a table, and a vertical rotation component;

the workbench is of a rectangular frame type structure, and the trolley is of a flat car type structure;

The vertical rotating assembly comprises a central shaft, a central shaft seat, a vertical shaft, a thrust ball bearing and an outer spherical ball bearing of a jackscrew with a square seat;

the axis of the central shaft and the axis of the vertical shaft are perpendicular to the object carrying plane of the trolley;

The central shaft seat is welded and fixed on the trolley, the bottom of the central shaft is inserted and fixed in a central hole in the central shaft seat, and the top of the central shaft passes through a through hole in a bottom plate of the workbench;

The seat ring of the thrust ball bearing is sleeved on the outer diameter surface of the circular convex ring in the central shaft seat, the shaft ring of the thrust ball bearing is sleeved on the outer diameter surface of the central shaft, and the bottom flat plate of the workbench is overlapped and placed on the shaft ring in the thrust ball bearing;

The outer spherical ball bearing is overlapped on the upper long and wide surface of the bottom plate of the workbench, the inner ring of the outer spherical ball bearing is sleeved on the outer diameter surface of the central shaft, and the square seat in the outer spherical ball bearing is connected with the bottom plate of the workbench through bolts;

The lower flange plate is fixedly arranged on the top end surface of the central shaft through countersunk bolts;

An upper flange plate is welded at the bottom end of the vertical shaft and is superposed on the lower flange plate, and the upper flange plate and the lower flange plate form a bolt connection through bolts;

The top end of the vertical shaft is fixedly connected with the top beam of the workbench through a hoop;

the trolley is fixed, and the workbench rotates along a vertical axis through the thrust ball bearing and the outer spherical ball bearing.

4. A heavy duty platform assembly line according to claim 3, wherein the thrust ball bearing is provided with a protective sleeve over the outer diameter surface.

5. A heavy duty platform assembly line according to claim 3, wherein the length of the trolley is 1/3-1/2 of the length of the table.

6. A heavy duty platform assembly line according to claim 3, wherein the work table of rectangular frame type structure is made of aluminium profiles assembled by splicing.