Device for heat-fitting bearing and main shaft

Abstract

The present invention relates to the technical field of bearing assembly, and discloses a device for heat-fitting bearings and spindles, comprising: a workbench; a second fixed block is placed on the workbench, and a groove is arranged around the top surface of the second fixed block; a heating element is arranged in the groove; the inner ring of the bearing to be assembled is fitted with the heating element; a spindle is connected to a telescopic guide structure; the device for heat-fitting bearings and spindles is suitable for the heating element to heat the inner ring of the bearing, and the telescopic guide structure drives the spindle to descend to assemble the spindle to the inner ring of the bearing. The present application fixes the bearing, and moves the spindle to cooperate with the inner ring of the bearing to avoid damaging the bearing; and combines the method of heating only the inner ring of the bearing to prevent the bearing from cooling down quickly. When the spindle passes through the inner ring of the bearing, only the inner ring of the bearing is stressed, and the outer ring of the bearing is not stressed, which can avoid deformation of the bearing or misalignment of the balls inside the bearing, ensure the quality and precision of the bearing, and achieve high-precision assembly.

Description

Technical Field

[0001] The invention relates to the technical field of bearing assembly, and in particular to a device for heat-fitting a bearing and a main shaft. Background Art

[0002] A molecular pump is a device that relies on the cooperation of the internal high-speed rotating turbine rotor and the stationary fixed blades to achieve air extraction to create and maintain a vacuum environment. The speed of the above-mentioned turbine rotor can reach more than 70,000 r / min. The stable high-speed rotation of the turbine rotor depends on the quality of the bearing and the matching accuracy of the main shaft and the bearing. When the assembly accuracy of the main shaft and the bearing is not good, for example: the shaft shoulder of the main shaft and the end face of the inner ring of the bearing are not completely fitted, the main shaft and the inner ring of the bearing are too loose or too tight, so that when the turbine rotor of the molecular pump is running at high speed, the bearing is prone to vibration and rapid temperature rise, so that the grease or lubricating oil inside the bearing evaporates quickly, and then burns the bearing, causing the turbine rotor to stop suddenly, and then causing the turbine rotor to break in an instant. The bearings of molecular pumps are generally precision bearings. Precision bearings include: inner rings and outer rings, the inner ring cooperates with the main shaft, when assembling the bearings, pressure should be applied to the inner ring of the bearing to cooperate with the main shaft, generally relying on external force on the outer ring of the bearing for assembly, the above method can easily cause deformation of the bearing or misalignment of the balls inside the bearing, etc., seriously affecting the quality and accuracy of the bearing. In addition, the inner ring of the main shaft and the bearing is an interference fit. It is usually necessary to calculate the temperature at which the bearing needs to be heated based on the matching size of the main shaft and the bearing and the thermal expansion of the main shaft and the bearing, and then match it with the main shaft. The existing method of heating the bearing as a whole can easily cause the grease inside the bearing to volatilize, reducing the service life of the bearing; and the dimensions of the outer ring, cage and ball of the bearing will be affected, seriously affecting the assembly accuracy; in addition, in the process of removing the bearing from the heating device and passing it through the main shaft, the bearing will cool down rapidly, seriously affecting the assembly process and assembly accuracy. If the temperature loss is compensated by increasing the heating temperature of the bearing, it is easy to make the inner ring of the bearing and the main shaft fit too tightly, and the turbine rotor will cause too much burden on the inner ring of the bearing when rotating at high speed, resulting in an increase in the bearing temperature, which will seriously affect the stability and service life of the molecular pump. Summary of the invention

[0003] In view of this, the present invention provides a device for hot-fitting bearings and spindles to solve the problems of relying on applying external force to the outer ring of the bearing to assemble the spindle and the bearing, which can easily cause the bearing to deform or the balls inside the bearing to be misaligned, and heating the bearing as a whole can easily cause the grease inside the bearing to volatilize, thereby reducing the service life of the bearing; and the sizes of the outer ring, retaining cage and balls of the bearing will all be affected, seriously affecting the assembly accuracy; in addition, in the process of removing the bearing from the heating device to passing through the spindle, the bearing will cool down rapidly, seriously affecting the assembly process and assembly accuracy.

[0004] The present invention provides a device for shrink-fitting a bearing and a main shaft, comprising:

[0005] Workbench;

[0006] A second fixing block is placed on the workbench, and a groove is arranged around the top surface of the second fixing block;

[0007] A heating element is arranged in the groove; the inner ring of the bearing to be assembled is arranged in contact with the heating element;

[0008] A telescopic guide structure is arranged on the workbench, and a main shaft is connected to the telescopic guide structure; the bottom end of the main shaft is located directly above the inner ring of the bearing; the telescopic guide structure is suitable for driving the main shaft to rise and fall;

[0009] The device for hot-fitting the bearing and the spindle is suitable for the heating element to heat the inner ring of the bearing, and the telescopic guide structure drives the spindle to descend so as to assemble the spindle to the inner ring of the bearing. Beneficial effect: The present application adopts the above technical solution, changes the previous assembly method of the bearing and the spindle by fixing the spindle and applying pressure to the outer ring of the bearing, and fixes the bearing and cooperates with the inner ring of the bearing by moving the spindle to avoid damaging the bearing; and combines the method of heating only the inner ring of the bearing to prevent the bearing from cooling down quickly. When the spindle passes through the inner ring of the bearing, only the inner ring of the bearing is stressed, and the outer ring of the bearing is not stressed, which can avoid deformation of the bearing or misalignment of the ball inside the bearing, etc., ensure the assembly quality, assembly efficiency and assembly accuracy of the bearing, achieve high-precision assembly and fit, and is manually controllable. At the same time, only the inner ring of the bearing that cooperates with the spindle is heated to avoid the volatilization of grease inside the bearing as much as possible.

[0010] Optionally, it also includes:

[0011] At least two first fixing blocks are connected in a surrounding form through a second elastic member; the outer ring of the bearing is located in the surrounding first fixing block; and the second fixing blocks are at least two arranged in a surrounding manner. Beneficial effect: The present application adopts the above technical solution to fix the position of bearings of different sizes, which is highly practical and widely applicable.

[0012] Optionally, the telescopic guide structure includes:

[0013] A connecting block, the bottom end of which is connected to the top end of the main shaft;

[0014] A cylinder connected to the top of the connecting block; the cylinder is suitable for driving the connecting block to rise and fall, thereby driving the main shaft to rise and fall;

[0015] A supporting block connected to the connecting block;

[0016] The guide column is fixed on the workbench in the vertical direction; the support block is slidably connected to the guide column. Beneficial effect: The present application adopts the above technical solution, and by setting the guide column, the coaxiality of the main shaft when passing through the inner ring of the bearing is ensured.

[0017] Optionally, the telescopic guide structure further includes:

[0018] A stud is fixed on the workbench in a vertical direction; a support arm is provided on the outer periphery of the support block, and the support arm is sleeved on the stud;

[0019] A positioning ring is spirally connected to the stud, and the positioning ring is located below the support arm to limit the position of the support arm, thereby limiting the limit position of the main shaft descent. A scale line along the height direction is provided on the guide column to refer to the scale line to determine the position of the positioning ring. Beneficial effect: The present application adopts the above technical solution, and the scale line is set to provide a reference for the position setting of the positioning ring.

[0020] Optionally, the telescopic guide structure further includes:

[0021] The upper part of the stud is a threaded part, the lower part of the stud is a smooth rod part, the support pad is arranged at the bottom end of the smooth rod part, and a first elastic member is arranged between the threaded part and the support pad. Beneficial effect: The present application adopts the above technical solution, and by arranging the first elastic member and the support pad, when the main shaft is assembled with the bearing, the bearing will not be further damaged, and the bearing can be effectively protected.

[0022] Optionally, it also includes:

[0023] The box has a closed cavity, and the workbench, the second fixed block, the heating element and the telescopic guide structure are all arranged in the cavity of the box; the bearing is a molecular pump bearing, and the main shaft is a molecular pump main shaft; two openings are arranged on the side wall of the box, and a fixing ring is arranged on the opening, and a rubber glove is fixed through the fixing ring; the rubber glove is suitable for operation in the box. Beneficial effect: The present application adopts the above technical scheme, and by setting up a box, it is ensured that the main shaft of the molecular pump and the bearing of the molecular pump are hot-mounted in a clean and dust-free environment; after the precision molecular pump bearing is disassembled and packaged, the surface oil film will not be destroyed by impurities or dust in the air, and even enter the inside of the bearing, affecting the life and precision of the bearing; by combining the fixing ring with the rubber glove, the rubber glove is used to operate the assembly of the bearing and the main shaft, so as to avoid the staff from directly contacting the molecular pump bearing with their hands, thereby avoiding the sweat on the hands from destroying the oil film on the surface of the bearing, affecting the life and precision of the bearing; and the box is small in size, easy to take and put, and can be taken and used at any time, with small investment and low cost.

[0024] Optionally, it also includes:

[0025] A temperature sensor is arranged near the inner ring of the bearing, and the temperature sensor is suitable for obtaining the temperature of the inner ring of the bearing;

[0026] Thermostat is arranged outside the box, and the temperature controller is connected to the temperature sensor and the heating element by signal. The temperature controller is suitable for obtaining the temperature signal transmitted by the temperature sensor and displaying it, and controlling the temperature of the heating element by controlling the power of the heating element. Beneficial effect: The present application adopts the above technical solution, and by setting the thermostat, the heating temperature of the heating element can be set according to the demand, the temperature of the inner ring of the bearing can be maintained, the temperature condition can be displayed in real time, and the high-precision matching between the main shaft and the inner ring of the bearing can be achieved.

[0027] Optionally, the box includes:

[0028] Front panel, located at the front;

[0029] The top plate, located at the top;

[0030] rear panel, located at the rear;

[0031] A first bottom plate is located at the bottom; the top of the front panel is sealed to the top plate via an inclined panel, the top plate is sealed to the rear panel, and the rear panel and the front panel are both sealed to the first bottom plate;

[0032] Two side frames, respectively arranged on both sides;

[0033] The two side door panels are provided with locking bayonets, and the two side door panels cooperate with the locking bayonets through plum nuts and are respectively locked and connected with the two side frames. A sealing rubber ring is provided between the side door panels and the side frames.

[0034] Optionally, it also includes:

[0035] A fan is arranged on the box body, and the fan is suitable for blowing air into the box body to obtain a positive pressure environment in the box body; a protective net is arranged on the fan to protect the safety of personnel;

[0036] The dustproof net is fixedly arranged on the opening of the box; the dustproof net is suitable for purifying the air entering the box. Beneficial effect: The present application adopts the above technical solution, and by setting the dustproof net, the purpose of purifying the air inside the box is achieved, and it is not polluted by the external environment, and a reliable dust-free environment is provided in the box; by setting the fan, a reliable positive pressure environment is provided in the box, which is conducive to the assembly of the main shaft and bearings, and reduces the investment cost. By setting the protective net, the operator is prevented from being injured by the fan.

[0037] Optionally, the first bottom plate is a stainless steel plate. Beneficial effects: The present application adopts the above technical solution, and by setting the first bottom plate to be a stainless steel plate, it is possible to allow parts to be subjected to certain bumps during the mechanical assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the three-dimensional structure of a device for shrink-fitting a bearing and a main shaft provided in an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of a partial three-dimensional structure of a device for shrink-fitting a bearing and a main shaft provided in an embodiment of the present invention Figure 1 ;

[0041] Figure 3 A schematic diagram of a partial three-dimensional structure of a device for shrink-fitting a bearing and a main shaft provided in an embodiment of the present invention Figure 2 ;

[0042] Figure 4 A schematic diagram of a partial three-dimensional structure of a device for shrink-fitting a bearing and a main shaft provided in an embodiment of the present invention Figure 3 .

[0043] Description of reference numerals:

[0044] 1. Thermostat; 2. Box body; 3. Side door panel; 4. Top plate; 5. Bevel panel; 6. Sealing rubber ring; 7. First bottom plate; 8. Front panel; 9. Fixing ring; 10. Side frame; 11. Locking bayonet; 12. Plum nut; 13. Protective net; 14. Fan; 15. Fixing plate; 16. Dust net; 17. Workbench; 18. Adjustment assembly; 19. Support pad; 20. First elastic member; 21. Stud; 22. Positioning ring; 23. Support arm; 24. Guide column; 25. Cylinder; 26. Support block; 27. Connecting block; 28. Spindle; 29. ​​Bearing; 30. Fixing member; 31. Second bottom plate; 32. First fixing block; 33. Second fixing block; 34. Temperature sensor; 35. Heating member; 36. Second elastic member. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0046] Generally, the bearing lubrication methods of molecular pumps are divided into oil lubrication, grease lubrication and air film bearings. Regardless of the lubrication method, when assembling the bearing, the cleanliness of the environment is very high, and a separate area is generally required for bearing assembly. When assembling the bearing, you cannot touch the bearing directly with your hands, because sweat and dust on your hands will destroy the oil film on the bearing, affecting the life and accuracy of the bearing. Bearings are usually packaged in vacuum sealed bags. In the process of assembling the bearing, after assembling one bearing, remove another bearing from the vacuum sealed bag to avoid the impact of ambient temperature and humidity on the quality of the bearing. Assembling the bearing under a positive pressure environment will reduce the adverse effects on the bearing and appropriately increase the life and accuracy of the bearing. In addition, the spindle and the bearing need to have an appropriate interference fit; if the bearing and the spindle are too loose, the turbine rotor will vibrate when rotating at high speed, and the vibration will cause the bearing to burn and the turbine rotor to break, and the turbine rotor will lose speed; if the bearing and the spindle are too tight, it will cause too much burden on the inner ring of the bearing, and the bearing temperature will rise, thereby affecting the stability and service life of the molecular pump.

[0047] The service life and working performance of the molecular pump depend largely on the quality of the bearings and the matching accuracy between the bearings and the spindle. The bearings used in the molecular pump are all high-precision bearings. The bearings will be subjected to vibration detection and noise detection during the production process. The defective products will be removed through waveform detection to ensure the quality requirements of the bearings. In fact, the factors that have the greatest impact on the quality of the bearings are: irregular operations from the removal of the bearing packaging to the assembly of the bearings and the spindle; for example: poor cleanliness of the bearings, direct contact with the bearings by hand, the influence of ambient temperature and humidity, the matching accuracy of the bearings and the spindle, etc., will affect the life and accuracy of the bearings. The service life of the bearings directly affects the service life of the molecular pump. Therefore, without the right environment and the right tools, the assembly of the high-precision bearings and the spindle of the molecular pump cannot avoid damage to the bearings due to environmental or human factors and serious reduction of the matching accuracy of the bearings and the spindle.

[0048] Combined with the prior art, in summary, the assembly of existing molecular pump bearings has the following problems: 1. After the precision bearings are disassembled and packaged, they are exposed to the air. Impurities or dust in the air will destroy the oil film on the bearing surface and even enter the inside of the bearing, seriously affecting the life and accuracy of the bearing. 2. When assembling precision bearings, the hands are directly used to assemble the bearings and the spindle. The sweat on the hands can easily destroy the oil film on the bearing surface, seriously affecting the life and accuracy of the bearing. 3. When assembling the bearings and the spindle, it is difficult to ensure the coaxiality of the inner ring of the bearing and the spindle, resulting in the problem of the bearing and the spindle not being assembled in place, that is, the bearing and the spindle are not perpendicular. At the same time, it is easy for the bearing to get stuck, making it difficult to assemble the bearing to the shoulder of the spindle, and even scratching the spindle. 4. Bearings are usually packaged in vacuum sealed bags. The ambient temperature and humidity during the assembly process can easily affect the quality of the bearings. 5. Assembling the bearing with the spindle in a positive pressure environment will reduce the adverse effects on the bearing and increase the life and precision of the bearing. However, positive pressure equipment is usually only available in large clean rooms, which makes the assembly cost of the bearing high and requires a large investment. For the above reasons, the present application proposes a device for heat-fitting the bearing with the spindle.

[0049] like Figures 1 to 4 A specific embodiment of the device for heat-fitting bearings and spindles shown includes: a workbench 17, a first fixed block 32, a second fixed block 33, a heating element 35, a telescopic guide structure, a box 2, a temperature sensor 34, a temperature controller 1, a fan 14 and a dustproof net 16.

[0050] like Figure 3 and Figure 4 As shown, the second fixing block 33 is placed on the workbench 17, and a groove is arranged around the top surface of the second fixing block 33. The heating element 35 is arranged in the groove; the heating element 35 can be a thermal resistance wire. The inner ring of the bearing 29 to be assembled is arranged in contact with the heating element 35. The telescopic guide structure is arranged on the workbench 17, and the main shaft 28 is connected to the telescopic guide structure; the bottom end of the main shaft 28 is located directly above the inner ring of the bearing 29; the telescopic guide structure is suitable for driving the main shaft 28 to rise and fall. The device for shrink-fitting the bearing and the main shaft is suitable for the heating element 35 to heat the inner ring of the bearing 29, and the telescopic guide structure drives the main shaft 28 to descend, so as to assemble the main shaft 28 to the inner ring of the bearing 29. Further, the adjusting components 18 can be respectively arranged at the four top corners of the bottom of the workbench 17; the adjusting components 18 are composed of a support block, a screw and a support foot connected in sequence from top to bottom; the screw is threadedly connected to the support block, and the height of the workbench 17 is adjusted by screwing the screw.

[0051] like Figure 4As shown, at least two first fixed blocks 32 are connected in a surrounding form through a second elastic member 36; the outer ring of the bearing 29 is located in the surrounding first fixed block 32; and the second fixed blocks 33 are at least two arranged in a surrounding manner. Specifically, the second elastic member 36 can be a spring. The number of the first fixed blocks 32 is four symmetrically arranged, and the number of the second fixed blocks 33 is four symmetrically arranged. The four first fixed blocks 32 and the four second fixed blocks 33 can be fixedly connected together respectively. Further, the first fixed block 32 and the second fixed block 33 can be located on the second bottom plate 31 arranged on the workbench 17.

[0052] like Figure 1 and Figure 2 As shown, the box body 2 has a closed cavity, and the workbench 17, the second fixed block 33, the heating element 35 and the telescopic guide structure are all arranged in the cavity of the box body 2; the bearing 29 is a molecular pump bearing, and the main shaft 28 is a molecular pump main shaft; two openings are provided on the side wall of the box body 2, and a fixing ring 9 is provided on the opening, and a rubber glove is fixed by the fixing ring 9; the rubber glove is suitable for operation in the box body 2.

[0053] like Figure 2 and Figure 4 As shown, the temperature sensor 34 is arranged near the inner ring of the bearing 29, and the temperature sensor 34 is suitable for obtaining the temperature of the inner ring of the bearing 29. The temperature controller 1 is arranged outside the housing 2, and the temperature controller 1 is connected to the temperature sensor 34 and the heating element 35 by signal. The temperature controller 1 is suitable for obtaining the temperature signal transmitted by the temperature sensor 34, and displaying it, and controlling the temperature heated by the heating element 35 by controlling the power of the heating element 35. The temperature sensor 34 can be a PT1000 sensor. The temperature controller 1 is arranged at the top of the housing 2. The inner ring of the main shaft 28 and the bearing 29 needs to be interference fit. According to the matching size of the two and the thermal expansion of the main shaft 28 and the bearing 29, the optimal temperature to which the inner ring of the bearing 29 needs to be heated is calculated. The heating element 35 is controlled by the temperature controller 1 to obtain the optimal temperature.

[0054] like Figure 1 and Figure 2As shown, the box body 2 includes: a front panel 8, a top panel 4, a rear panel, a first bottom panel 7, two side frames 10 and two side door panels 3. The side door panels 3 are acrylic panels. The front panel 8 and the top panel 4 are both aluminum panels. The front panel 8, the top panel 4 and the side frames 10 can all be made of LY12 aluminum alloy. The front panel 8 is located at the front; the top panel 4 is located at the top; the rear panel is located at the rear; the first bottom panel 7 is located at the bottom, and the first bottom panel 7 is a stainless steel plate. The top end of the front panel 8 is sealedly connected to the top panel 4 through an inclined panel 5, the top panel 4 is sealedly connected to the rear panel, and the rear panel and the front panel 8 are both sealedly connected to the first bottom panel 7. Two side frames 10 are respectively arranged on both sides; the two side door panels 3 are provided with locking bayonets 11, and the two side door panels 3 are respectively locked and connected to the two side frames 10 through plum nuts 12 and the locking bayonets 11, and a sealing rubber ring 6 is provided between the side door panels 3 and the side frames 10. The above-mentioned sealing connection can be welded, which not only has high connection strength but also has strong applicability. The fan 14 is arranged on the box body 2, and the fan 14 is suitable for blowing air into the box body 2 to obtain a positive pressure environment in the box body 2; a protective net 13 is arranged on the fan 14 to protect the safety of personnel. The dustproof net 16 is fixedly arranged on the opening of the box body 2 through a fixing plate 15; the dustproof net 16 is suitable for purifying the air entering the box body 2. Multiple fans 14 and dustproof nets 16 can be provided.

[0055] like Figure 3 As shown, the telescopic guide structure includes: a connecting block 27, a cylinder 25, a support block 26, a guide column 24, a stud 21, a positioning ring 22 and a support pad 19.

[0056] The bottom end of the connecting block 27 is connected to the top end of the main shaft 28. The cylinder 25 is connected to the top end of the connecting block 27; the cylinder 25 is suitable for driving the connecting block 27 to rise and fall, thereby driving the main shaft 28 to rise and fall. The support block 26 is connected to the connecting block 27. The guide column 24 is fixed on the workbench 17 in the vertical direction; specifically, the bottom end of the guide column 24 is fixed on the workbench 17 by a fixing member 30; the guide columns 24 may be two symmetrically spaced. The support block 26 is slidably connected to the guide column 24. The stud 21 is fixed on the workbench 17 in the vertical direction; the stud 21 may be two symmetrically spaced. A support arm 23 is provided on the outer periphery of the support block 26, and the support arm 23 may be two symmetrically spaced. The support arm 23 is sleeved on the stud 21. The positioning ring 22 is spirally connected to the stud 21, and the positioning ring 22 is located below the support arm 23 to limit the position of the support arm 23, and further limit the lowering limit position of the main shaft 28. The guide column 24 is provided with a scale line along the height direction, so as to determine the position of the positioning ring 22 with reference to the scale line. The upper part of the stud 21 is a threaded part, and the lower part of the stud 21 is a smooth rod part. The support pad 19 is arranged at the bottom end of the smooth rod part, and a first elastic member 20 is provided between the threaded part and the support pad 19. The first elastic member 20 can be a spring. The support pad 19 can be a rubber pad.

[0057] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A device for shrink-fitting a bearing and a spindle, characterized in that: include: Workbench (17); A second fixing block (33) is placed on the workbench (17), and a groove is arranged around the top surface of the second fixing block (33); A heating element (35) is disposed in the groove; an inner ring of the bearing (29) to be assembled is disposed in close contact with the heating element (35); a telescopic guide structure, arranged on the workbench (17), a main shaft (28) being connected to the telescopic guide structure; the bottom end of the main shaft (28) is located directly above the inner ring of the bearing (29); the telescopic guide structure is suitable for driving the main shaft (28) to move up and down; The device for shrink-fitting the bearing and the main shaft is suitable for the heating element (35) to heat the inner ring of the bearing (29), and the telescopic guide structure drives the main shaft (28) to descend, so as to assemble the main shaft (28) to the inner ring of the bearing (29); Also includes: At least two first fixing blocks (32) are connected in a surrounding manner via a second elastic member (36); the outer ring of the bearing (29) is located inside the surrounding first fixing block (32); and the second fixing blocks (33) are at least two arranged in a surrounding manner; Also includes: The box (2) has a sealed cavity, and the workbench (17), the second fixed block (33), the heating element (35) and the telescopic guide structure are all arranged in the cavity of the box (2); the bearing (29) is a molecular pump bearing, and the main shaft (28) is a molecular pump main shaft; two openings are provided on the side wall of the box (2), and a fixing ring (9) is provided on the opening, and a rubber glove is fixed by the fixing ring (9); the rubber glove is suitable for operating in the box (2).

2. The device for shrink-fitting a bearing and a main shaft according to claim 1, characterized in that: The telescopic guide structure comprises: A connecting block (27), the bottom end of which is connected to the top end of the main shaft (28); A cylinder (25) connected to the top end of the connecting block (27); the cylinder (25) is suitable for driving the connecting block (27) to move up and down, thereby driving the main shaft (28) to move up and down; A supporting block (26) connected to the connecting block (27); A guide column (24) is fixed on the workbench (17) in a vertical direction; and the support block (26) is slidably connected to the guide column (24).

3. The device for shrink-fitting a bearing and a main shaft according to claim 2, characterized in that: The telescopic guide structure also includes: A stud (21) is fixed on the workbench (17) in a vertical direction; a support arm (23) is provided on the outer periphery of the support block (26), and the support arm (23) is sleeved on the stud (21); A positioning ring (22) is spirally connected to the stud (21), and the positioning ring (22) is located below the support arm (23) to limit the position of the support arm (23), thereby limiting the lowering limit position of the main shaft (28). The guide column (24) is provided with a scale line along the height direction, so that the position of the positioning ring (22) can be determined with reference to the scale line.

4. The device for shrink-fitting a bearing and a main shaft according to claim 3, characterized in that: The telescopic guide structure also includes: A support pad (19), wherein the upper portion of the stud (21) is a threaded portion, the lower portion of the stud (21) is a smooth rod portion, the support pad (19) is arranged at the bottom end of the smooth rod portion, and a first elastic member (20) is provided between the threaded portion and the support pad (19).

5. The device for shrink-fitting a bearing and a main shaft according to claim 1, characterized in that: Also includes: a temperature sensor (34), arranged close to the inner ring of the bearing (29), the temperature sensor (34) being suitable for obtaining the temperature of the inner ring of the bearing (29); A temperature controller (1) is arranged outside the box (2); the temperature controller (1) is signal-connected to the temperature sensor (34) and the heating element (35); the temperature controller (1) is suitable for obtaining a temperature signal transmitted by the temperature sensor (34), displaying the temperature signal, and controlling the temperature heated by the heating element (35) by controlling the power of the heating element (35).

6. The device for shrink-fitting a bearing and a main shaft according to claim 1, characterized in that: The box (2) comprises: A front panel (8), located at the front; A top plate (4), located at the top; rear panel, located at the rear; A first bottom plate (7) is located at the bottom; the top end of the front panel (8) is sealedly connected to the top plate (4) via an inclined panel (5); the top plate (4) is sealedly connected to the rear panel; and the rear panel and the front panel (8) are both sealedly connected to the first bottom plate (7); Two side frames (10), respectively arranged on both sides; The two side door panels (3) are provided with locking bayonets (11). The two side door panels (3) cooperate with the locking bayonets (11) through plum nuts (12) and are respectively locked and connected to the two side frames (10). A sealing rubber ring (6) is provided between the side door panels (3) and the side frames (10).

7. The device for shrink-fitting a bearing and a main shaft according to claim 1, characterized in that: Also includes: a fan (14) disposed on the box (2), the fan (14) being suitable for blowing air into the box (2) to obtain a positive pressure environment in the box (2); a protective net (13) is provided on the fan (14) to protect the safety of personnel; A dustproof net (16) is fixedly arranged on the opening of the box body (2); the dustproof net (16) is suitable for purifying the air entering the box body (2).

8. The device for shrink-fitting a bearing and a main shaft according to claim 6, characterized in that: The first bottom plate (7) is a stainless steel plate.

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