CN113771909B

CN113771909B - Axle box bearing assembly method and assembly device for axle box built-in bogie

Info

Publication number: CN113771909B
Application number: CN202111152419.5A
Authority: CN
Inventors: 闫婷婷; 王晓宁; 范德万; 祝帅; 韩宁
Original assignee: CRRC Qingdao Sifang Co Ltd
Current assignee: CRRC Qingdao Sifang Co Ltd
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2023-07-18
Anticipated expiration: 2041-09-29
Also published as: CN113771909A

Abstract

The invention provides an assembling method and an assembling device of an axle box bearing of an axle box built-in bogie, comprising the following steps: the sealing ring and the axle box rear cover are pressed and assembled to the rear end of the axle box body; pressing the bearing into the axle box body from front to back, and installing an axle box front cover to press the bearing, thereby forming an axle box bearing assembly; the pedestal bearing assembly is press-fit onto an axle. In the embodiment of the invention, the axle box body and the bearing are assembled into an integral assembly and then are pressed on the axle, so that the assembly of the bearing of the bogie with the built-in axle box, the axle box body and the axle is smoothly realized.

Description

Axle box bearing assembly method and assembly device for axle box built-in bogie

Technical Field

The invention relates to the technical field of railway vehicles, in particular to an assembling method and an assembling device of an axle box bearing of an axle box built-in bogie.

Background

The bearing of the traditional wheel set is firstly pressed on the axle, and then the axle box is pressed. However, the axle box bearing structure of the axle box built-in bogie is different from the conventional wheel set in assembly and is difficult to assemble in a conventional manner.

Disclosure of Invention

The invention provides an assembling method of an axle box bearing of an axle box built-in bogie, which comprises the following steps:

the sealing ring and the axle box rear cover are pressed and assembled to the rear end of the axle box body;

pressing the bearing into the axle box body from front to back, and installing an axle box front cover to press the bearing, thereby forming an axle box bearing assembly;

the pedestal bearing assembly is press-fit onto an axle.

In a specific scheme, when the sealing ring and the axle box rear cover are pressed, the rear end of the axle box body faces upwards; before the bearing is pressed to the axle box, the axle box is adjusted to be upward in front end.

In a specific scheme, a guide part is fixed at one end of an axle, an axle box bearing assembly is sleeved on the guide part, and the axle box bearing assembly is pushed to move axially along the guide part through a press fit sleeve so as to gradually approach the axle, and finally the axle box bearing assembly is pressed to the corresponding position of the axle.

The invention also provides an assembling device of the axle box bearing of the axle box built-in bogie, which is used for carrying out the axle box bearing assembling method of the axle box built-in bogie, and comprises a guide part and a press-fit sleeve, wherein the guide part is used for being fixed with one end of an axle, and the press-fit sleeve can cover the guide part so as to push the axle box bearing assembly to axially move along the guide part.

In a specific aspect, one end of the guiding portion is provided with a tapered end, and the tapered end can be inserted into an inner hole of one end of the axle for positioning.

In a specific scheme, the assembling device further comprises a plug pin, the guide part is provided with a jack extending in the radial direction, the jack is matched with the plug pin, and at least one jack is distributed in the circumferential direction by the guide part; the wall body of the press-fit sleeve is provided with long holes extending along the axial direction of the wall body, at least one long hole is circumferentially distributed in the press-fit sleeve, and the long holes penetrate through the inside and the outside of the wall body; the bolt is inserted into the corresponding jack and the slot hole, and the press-fit sleeve moves relative to the bolt when moving along the axial direction.

In a specific aspect, the assembly device further comprises a mobile press-fit pump, and the plug pin is vertically arranged and fixed with an inner column of the mobile press-fit pump.

In a specific scheme, the guide part comprises a first circular plate and a second circular plate which are concentrically distributed, a plurality of webs are arranged between the first circular plate and the second circular plate, and two ends of each web are respectively connected with the first circular plate and the second circular plate; one side edge of each of the webs is connected, and the webs extend along the radial direction; the cone end is arranged on the first circular plate, one end of the second circular plate is concentrically provided with a cylinder, and the jack is arranged on the cylinder.

In a specific aspect, the radial dimension of the cylinder is smaller than the radial dimensions of the first circular plate and the second circular plate, and the width of the web is equal to the radius of the first circular plate and the radius of the second circular plate.

The invention also provides an assembling device of the axle box bearing of the axle box built-in bogie, which is used for carrying out the axle box bearing assembling method of the axle box built-in bogie described in the second item, and comprises a supporting tool, wherein the supporting tool is used for axially supporting the axle box body which is provided with the sealing ring and the axle box rear cover in a pressing mode, the supporting tool comprises an annular base body, and a plurality of supporting blocks are distributed on the upper end face of the annular base body along the circumferential direction.

In the embodiment of the invention, the axle box body and the bearing are assembled into an integral assembly and then are pressed on the axle, so that the assembly of the bearing of the bogie with the built-in axle box, the axle box body and the axle is smoothly realized.

Drawings

Fig. 1 is a schematic diagram of press-fitting of a seal ring, a rear cover of an axle box and an axle box body in the embodiment;

FIG. 2 is a schematic diagram of a support tooling for a support axle housing;

FIG. 3 is a schematic illustration of the assembly of a bearing into an axle housing;

FIG. 4 is an axial cross-sectional view of the pedestal bearing assembly;

FIG. 5 is a right side view of FIG. 4;

FIG. 6 is a schematic view of an axle housing supported by the support tooling shown in FIG. 2;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is a schematic illustration of the assembled pedestal bearing assembly of FIG. 4 assembled to an axle shaft;

FIG. 9 is a schematic view of another embodiment of a guide portion;

FIG. 10 is a schematic view of the guide of FIG. 9 from another perspective;

FIG. 11 is a front view of FIG. 9;

FIG. 12 is a left side view of FIG. 11;

FIG. 13 is a right side view of FIG. 11;

FIG. 14 is a cross-sectional view taken along A-A of FIG. 11;

FIG. 15 is a schematic view of the press-fit sleeve of FIG. 8;

fig. 16 is a schematic view of the press-fit sleeve of fig. 15 from another perspective.

The reference numerals in fig. 1-16 are illustrated as follows:

1-an axlebox bearing assembly;

11-axle box; 111-positioning guide posts; 112-spring mount;

12-axle box rear cover; 13-a sealing ring; 14-a bearing; 15-axle box front cover; 16-bolts;

2-supporting the tool; 21-an annular matrix; 22-supporting blocks;

3. a 3' -guide part; 31-cone end; 3 A-A jack; 3 b-mounting holes; 32-a first circular plate; 33-a second circular plate; 34-web; 35-cylinder;

4-press fitting the sleeve; 4 a-long holes; 41-connection end;

5-bolts;

6-axle; 61-shaft shoulder.

Detailed Description

In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.

The present embodiment provides a method of assembling an axle box bearing of an axle box built-in bogie to assemble an axle box 11, a bearing, to an axle 6 (shown in fig. 8, a wheel seat corresponding to the axle 6 is located on the left side of the axle 6 in fig. 8, the wheel seat is not shown). The axial built-in bogie, i.e. axle box is located inside the wheel seat, and the wheel seat is used as reference, and the direction of the inner side of the wheel seat pointing to the outer side of the wheel seat is from front to back, and the front and back are all the standard.

As shown in fig. 1 and 2, fig. 1 is a schematic diagram illustrating press-fitting of a seal ring 13, a rear axle box cover 12 and an axle box 11 in the present embodiment; fig. 2 is a schematic diagram of the support tooling 2 supporting the axle housing 11.

First, the seal ring 13, the pedestal rear cover 12, may be press-fitted to the rear end of the pedestal body 11, the pedestal rear end being understood with reference to fig. 8, the rear end being close to the wheel seat of the corresponding side, and the front end being away from the wheel seat of the corresponding side. The pedestal back cover 12, i.e., the retainer ring structure shown in fig. 1, is adapted to withstand the bearing 14. In fig. 1, the upper end of the axle housing 11 is a rear end, and the lower end is a front end, wherein a top-down black arrow indicates a press-fitting direction. Specifically, the axle box 11 may be horizontally placed on the support tool 2 shown in fig. 2, where the inner hole of the axle box 11 extends in the vertical direction, and at this time, the rear end of the axle box 11 faces upward, that is, the rear end for installing the sealing ring 13 faces upward.

The sealing ring 13 and the axle box rear cover 12 are assembled together, then the assembly direction shown in fig. 1 is arranged above the axle box 11, the edge of the sealing ring 13 is lightly pressed into the inner hole of the axle box 11, and a rubber hammer can be used for uniformly and symmetrically knocking along the circumferential direction until the sealing ring 13 is completely pressed into the inner hole of the axle box 11, and the assembly requires that the upper edge of the sealing ring 13 is flush with the outer edge of the axle box 11.

Next, please continue to refer to fig. 3, fig. 3 is a schematic diagram illustrating the assembly of the bearing 14 into the axle housing 11.

As previously described, the seal ring 13 and the pedestal rear cover 12 have been mounted to the rear end of the pedestal 11, and the bearing 14 is required to be press-fitted into the pedestal 11 from front to rear. As shown in fig. 3, the axle box 11 can be vertically turned over, the rear end of fig. 1 is turned over upwards, the front end of fig. 3 is turned over upwards, the axle box is continuously supported on the supporting tool 2 shown in fig. 2, then the bearing 14 is slowly installed in the axial direction of the inner hole of the axle box 11 by using a hoisting tool, and in the assembling process, whether the angle of the bearing 14 is deviated or not is observed, so that the bearing 14 and the axle box 11 are prevented from being blocked and knocked.

After the bearing 14 is assembled, an axle box front cover 15 is mounted on the front end of the axle box 11 to press the front end of the bearing 14, and the axle box front cover 15 is also a retainer ring structure, and the front end of the axle box 11 is the oil seal ring side of the axle box 11. The axle box front cover 15 can be fastened by bolts 16, gasket spring pads and iron wires or steel wires, the axle box body 11, the bearing 14, the axle box front cover 15 and the axle box rear cover 14 are assembled to form the axle box bearing assembly 1, as shown in fig. 4 and 5, and fig. 4 is an axial cross-sectional view of the axle box bearing assembly 1;

fig. 5 is a right side view of fig. 4.

In the above-described assembly of the pedestal bearing assembly 1, the pedestal 11 is supported by the support fixture 2 shown in fig. 2, as shown in fig. 6 and 7, fig. 6 is a schematic view of the pedestal 11 supported by the support fixture 2 shown in fig. 2, and fig. 7 is a plan view of fig. 6.

The rear end of the axle box 11 needs to be assembled with the sealing ring 13 and the axle box rear cover 12, and the bearing 14 needs to be assembled into the axle box 11 from front to back, and it is known that the axle box 11 is placed with the inner hole extending vertically, i.e. being arranged in the direction shown in fig. 1 or 3, so as to facilitate the press-fitting work, but the structure of the axle box 11 is asymmetric, as shown in fig. 6 and 7, the axle box 11 as a whole comprises a positioning guide post 111 protruding outwards and two spring mounting seats 112, at this time, when the axle box is placed along the inner hole in the vertical direction, the axle box 11 cannot be stably placed, and the vertical placement of the axle box 11 can be realized through the supporting tool 2.

Referring to fig. 2 again, the supporting fixture 2 includes an annular base 21, the annular base 21 may be specifically a circular structure as shown in fig. 2, a plurality of supporting blocks 22 are disposed at an upper end of the annular base 21, three bar-shaped supporting blocks 22 are disposed in fig. 2, the bar-shaped supporting blocks 22 are uniformly distributed along a circumferential direction, and the bar-shaped supporting blocks 22 extend radially, as shown in fig. 6 and 7, the supporting blocks 22 support an end face of the axle box 11, and the positioning guide posts 111 and the spring mounting seats 112 of the axle box 11 are supported and lifted accordingly, so that the axle box can be stably located at a position to be pressed.

After the above-described pedestal bearing assembly 1 is assembled, the pedestal bearing assembly 1 is then press-fitted to the axle 6, thereby completing the assembly of the bearing 14, the pedestal 11, and the axle 6.

Specifically, with continued reference to fig. 8, fig. 8 is a schematic illustration of the assembled axle housing bearing assembly 1 of fig. 4 assembled to an axle shaft 6.

Firstly, fixing the guide part 3 at one end of the axle 6, sleeving the axle box bearing assembly 1 to the guide part 3, and processing a chamfer at the position where the guide part 3 is firstly contacted with the axle box bearing assembly 1, wherein the chamfer can be processed at the circumferential edge of the right end of the guide part 3 in fig. 8, and when the axle box bearing assembly 1 is preassembled on the guide part 3, the guide part can be slightly pushed in to ensure that the chamfer is contacted with the inner ring fillet of the axle box bearing assembly 1 so as to avoid or reduce damage possibly caused.

The pedestal bearing assembly 1 is then pushed by the press-fit sleeve 4 to move in the axial direction of the guide 3 to gradually approach the axle 6, and finally is sleeved at the corresponding position of the axle 6. That is, the guide portion 3 plays a role of guiding at the initial stage of assembling the axle box bearing assembly 1 to the axle 6, the guide portion 3 and the outer peripheral wall of the axle 6 are substantially flush, while the inner peripheral wall of the press-fit sleeve 4 is fitted with both the guide portion 3 and the outer peripheral wall of the axle 6, and the inner diameter of the press-fit sleeve 4 can be slightly larger than the outer diameters of the guide portion 3 and the axle 6, so that the axle box bearing assembly 1 can be pushed more stably.

9-13, FIG. 9 is a schematic view of another embodiment of a guide;

FIG. 10 is a schematic view of the guide of FIG. 9 from another perspective; FIG. 11 is a front view of FIG. 9; FIG. 12 is a left side view of FIG. 11; FIG. 13 is a right side view of FIG. 11; fig. 14 is a cross-sectional view taken along A-A of fig. 11.

The guide portion 3' in fig. 9 is another embodiment, and is different from the guide portion 3 in fig. 8 in that the guide portion 3 in fig. 8 is provided with an equal diameter except for the tapered end 31, and is equivalent to the outer diameter of the axle 6. In fig. 9, the section of the guide portion 3 'opposite to the tapered end 31 is a cylinder 35 having a smaller radial dimension than the other sections, so that the guide portion 3 and the guide portion 3' have the same other structures.

Specifically, the guide portion 3' includes a first circular plate 32 and a second circular plate 33 that are concentrically distributed, a plurality of webs 34 are disposed between the first circular plate 32 and the second circular plate 33, and two ends of the plurality of webs 34 are respectively connected to the first circular plate 32 and the second circular plate 33; one side of the webs 34 is connected, the webs 34 extend along the radial direction, in fig. 14, four webs 34 are arranged and distributed in a cross shape, the webs 34 can be arranged in other numbers, the main purpose of the webs 34 is to connect two circular plates, so that the strength is ensured, the weight of the whole guiding part 3' can be reduced, the two circular plates and the webs 34 can be in an integral structure, and the two circular plates and the webs 34 can be formed by cutting in a solid cylindrical structure or in a split structure. The width dimension of the web 34 may be equal to the radial dimension of the first circular plate 32, the second circular plate 33, such that the web 34 also supports, guides the pedestal bearing assembly 1 and the press-fit sleeve 4.

The tapered end 31 is provided in the middle of the first circular plate 32, and the first circular plate 32 is provided with a plurality of mounting holes 3b in the circumferential direction, and as shown in fig. 8, 9, 10, 11, bolts 5 may be inserted into the mounting holes 3b to be fastened into screw holes corresponding to one end of the axle 6, thereby fixing the guides 3, 3' and the axle 6. When fixing the guide parts 3, 3', the tapered ends 31 of the guide parts 3, 3' are inserted into the inner holes of the axle 6 to perform positioning, and then the bolts 5 are inserted to fix.

As shown in fig. 9, a cylinder 35 is concentrically disposed at one end of the second circular plate 33, and at least one insertion hole 3a is disposed in the circumferential direction of the cylinder 35, and four insertion holes 3a are shown in fig. 13, the insertion holes 3a extend in the radial direction, and when the axle 6, the axle box bearing assembly 1, the guide portion 3, and the press-fit bush 4 are aligned with each other with respect to the axis 8 as a view, the radial direction is a direction perpendicular to the axial direction.

As will be appreciated in conjunction with fig. 8, 15, 16, fig. 15 is a schematic view of the press-fit sleeve 4 of fig. 8; fig. 16 is a schematic view of the press-fit sleeve of fig. 15 from another perspective, wherein the press-fit sleeve 4 includes a connecting end 41 provided at an end portion in addition to the sleeve-shaped main body portion, and the connecting end 41 is not shown in fig. 8.

The wall body of the press-fit sleeve 4 is provided with long holes 4a extending along the axial direction of the press-fit sleeve, at least one long hole 4a is distributed in the circumferential direction of the press-fit sleeve 4, the number and the positions of the long holes 4a correspond to those of the insertion holes 3a, and the long holes 4a of the press-fit sleeve 4 penetrate through the inside and the outside of the wall body. The assembling device of the axle box bearing of this embodiment further includes a bolt (not shown in the figure), the bolt can be inserted into the corresponding jack 3a and the slot 4a, the bolt is positioned relative to the axle 6 and the guiding part 3 after being inserted into the jack 3a, and when the axle box bearing assembly 1 is pushed to move axially, the slot 4a moves relative to the bolt, and the sliding fit of the bolt and the slot 4a forms good guiding for pushing the press-fit sleeve 4.

As shown in fig. 8, when the axle box bearing assembly 1 is assembled, the axle 6 is horizontally arranged, and the axle box bearing assembly 1 is also placed in a direction in which the inner bore extends horizontally, and gradually sleeved toward the axle 6 in the axial direction of the inner bore thereof. During press fitting, the guide part 3 and the press fitting sleeve 4 can be adjusted, so that one inserting hole 3a is positioned at the bottom of the guide part 3 and extends vertically, one long hole 4a corresponds to the position of the inserting hole 3a, one end of an inserted bolt is inserted into the inserting hole 3a for positioning, the other end of the inserted bolt can penetrate through the long hole 4a and is supported on the ground or a table top, a certain supporting effect is provided for the whole assembly device, and the guide is more reliable. The latch structure is not limited, and can be inserted into the jack 3a for positioning or screwed for fixing. In addition, a plurality of insertion holes 3a and long holes 4a are provided, so that the insertion holes 3a and the long holes 4a can be conveniently paired for insertion of the plug pins.

The above mentioned functions of supporting, positioning and guiding the pin, it should be noted that the pin also functions as a fixed press-fit pump in this embodiment. In this scheme, the axle 6 is assembled together after the bearing 14 and the axle box 11 are assembled, the required press-fitting force is larger, and unlike the common bearing press-fitting machine, the movable press-fitting pump is adopted for press-fitting, so that the inner column and the bolt of the press-fitting pump can be fixed, the disc surface of the press-fitting pump is fixedly connected with the press-fitting sleeve 4, and as shown in fig. 15 and 16, the connecting end 41 of the press-fitting sleeve 4 can be connected with the disc surface of the fixed press-fitting pump. Thus, the inner column of the press-fit pump is contracted relative to the main body of the press-fit pump when in operation, and because the inner column of the press-fit pump is fixed with the bolt, the bolt is fixed relative to the axle 6, and the axle 6 is supported and fixed on the ground or a platform, the contraction action of the inner column correspondingly drives the press-fit pump to move, thereby driving the press-fit sleeve 4 to move so as to push the axle box bearing assembly 1 to press the guide part 3 and gradually approach the axle 6, and finally press-fit to the corresponding position of the axle 6. Therefore, the plug pin can also play a role in fixing the inner column of the movable press-fit pump, and the movable press-fit pump has the advantages of high flexibility and free height adjustment, and can meet the loading and positioning requirements of the axle 6. .

The maximum pressure value of the press-fit pump can be set to the final boost pressure when the pedestal bearing assembly 1 is pushed by the press-fit sleeve 4. When the pressure gauge is pressed in, attention should be paid to the fluctuation of the pressure gauge, and if a sudden pressure change occurs, the pedestal bearing assembly 1 should be removed to confirm whether or not damage such as seizing or the like is generated on the surface of the bearing 14. As shown in fig. 8, after the axle housing bearing assembly 1 is finally press-fitted in place, the axle housing rear cover 12 should be able to closely adhere to the R portion of the shoulder 61 of the axle 6, and in order to ensure that the adhesion is achieved, the final press-fitting may be performed using an adhesion pressure, that is, the final pressure increase described above.

As shown in fig. 4, the inner hole wall at the rear end of the axle box 11 has a step, and together with the rear end cover 12, it can play an axial stop role on the bearing 14, and as will be understood with reference to fig. 8, the left end of the axle 6 also has a wheel seat (not shown) in view of fig. 8, at this time, both the bearing 14 and the axle box 11 can only be relatively installed from the right side to the left side, if the bearing 14 is installed first, the axle box 11 cannot be installed but the bearing 14 is sleeved. In the embodiment of the invention, the axle box 11 and the bearing 14 are assembled into a whole assembly, and then are pressed onto the axle 6, so that the assembly of the bearing 14, the axle box 11 and the axle 6 of the bogie with the built-in axle box is successfully realized.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims

1. The method for assembling the axle box bearing of the axle box built-in bogie is characterized by comprising the following steps:

the sealing ring and the axle box rear cover are pressed and assembled to the rear end of the axle box body, and when the sealing ring and the axle box rear cover are pressed and assembled, the rear end of the axle box body is upward;

the bearing is pressed into the axle box body from front to back, the axle box body is adjusted to be upward at the front end before the bearing is pressed into the axle box body, and an axle box front cover is installed to press the bearing, so that an axle box bearing assembly is formed;

press-fitting the pedestal bearing assembly onto an axle;

fixing a guide part at one end of an axle, sleeving an axle box bearing assembly to the guide part, pushing the axle box bearing assembly to axially move along the guide part through a press fit sleeve so as to gradually approach the axle, and finally press-fitting the axle to the corresponding position of the axle;

the guide part is provided with a radially extending jack, the wall body of the press-fit sleeve is provided with a long hole extending along the axial direction of the wall body, and the long hole penetrates through the inside and the outside of the wall body; when the axle and the axle box bearing assembly are pressed, the insertion hole of the guide part is positioned at the bottom of the guide part and extends vertically, the long hole of the pressing sleeve corresponds to the position of the insertion hole, one end of the bolt is inserted into the insertion hole for positioning, and the other end of the bolt penetrates out of the long hole and is supported on the ground or the table top.

2. An assembling device of an axle box bearing of an axle box built-in bogie for carrying out the axle box bearing assembling method of the axle box built-in bogie according to claim 1, characterized in that the assembling device comprises a guide part and a press-fit sleeve, the guide part is used for being fixed with one end of an axle, and the press-fit sleeve can cover the guide part so as to push the axle box bearing assembly to axially move along the guide part;

the assembly device further comprises a plug pin, the guide part is provided with radially extending insertion holes, the insertion holes are matched with the plug pin, and at least one insertion hole is circumferentially distributed in the guide part; the wall body of the press-fit sleeve is provided with long holes extending along the axial direction of the wall body, at least one long hole is circumferentially distributed in the press-fit sleeve, and the long holes penetrate through the inside and the outside of the wall body; the bolt is inserted into the corresponding jack and the slot hole, and the press-fit sleeve moves relative to the bolt when moving along the axial direction.

3. An axle box bearing assembly device for an axle box built-in bogie as claimed in claim 2, wherein one end of said guide portion is provided with a tapered end which is capable of being positioned by being inserted into an inner hole of one end of said axle.

4. The axle box bearing assembly device of an axle box built-in bogie as set forth in claim 2, further comprising a mobile press-fit pump, said latch being vertically disposed and secured with an inner column of said mobile press-fit pump.

5. An axle box bearing assembly device for an axle box built-in bogie according to claim 3, wherein the guide part comprises a first circular plate and a second circular plate which are concentrically distributed, a plurality of webs are arranged between the first circular plate and the second circular plate, and two ends of the webs are respectively connected with the first circular plate and the second circular plate; one side edge of each of the webs is connected, and the webs extend along the radial direction; the cone end is arranged on the first circular plate, one end of the second circular plate is concentrically provided with a cylinder, and the jack is arranged on the cylinder.

6. The axle box bearing assembly device of an axle box built-in bogie according to claim 5, wherein a radial dimension of the cylinder is smaller than a radial dimension of the first circular plate and the second circular plate, and a width of the web is equal to a radius of the first circular plate and the second circular plate.

7. An axle box bearing assembly device for an axle box built-in bogie as claimed in any one of claims 2-6, wherein said assembly device comprises a support fixture for axially supporting said axle box body press-fitted with said seal ring and said axle box rear cover, said support fixture comprises an annular base body, and a plurality of support blocks are circumferentially distributed on an upper end surface of said annular base body.