Axial loading device for bearing testing

Abstract

The present invention provides an axial loading device for bearing testing, comprising a damping unit, a loading unit, a clutch unit and a test bearing unit. The clutch unit provided in the present invention can realize that when the test bearing roller and the outer ring are bonded at high temperature, the axial loading mechanism is quickly separated from the test bearing, and the loading is carried out in a "linear actuator + lever + permanent magnet" manner, so as to achieve the purpose of accurately and continuously adjusting the axial force applied to the test bearing within a larger range. In addition, the present invention is provided with a variable damping mechanism to improve the measurement anti-interference and measurement accuracy of the device, and can also realize axial loading tests on bearings of various models in a set of devices. The overall structure is simple and reasonable, and the manufacturing and use costs are low.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing test equipment, and in particular relates to an axial loading device for bearing test. Background Art

[0002] Rolling bearings are widely used in various mechanical equipment due to their significant advantages. Their motion accuracy determines the accuracy and performance of mechanical equipment, but rolling bearings are also one of the key components in mechanical equipment that is most prone to failure. There are many types of bearing failures, among which the failure caused by slippage accounts for the highest proportion of total failures; when rolling bearings slide during operation, not only does the friction coefficient increase, but a large amount of heat is also generated, which will affect the motion accuracy and mechanical efficiency of the rolling bearings, and also reduce the service life of the rolling bearings. The occurrence of rolling bearing slippage can be effectively prevented by applying an appropriate axial preload. In the research and development, design and testing of bearings, by changing the size of the applied axial preload to make the rolling bearings slip to different degrees, the damage behavior of the working surface of the rolling bearings under different rolling-slip ratios can be simulated, providing a scientific basis for the design and application of bearings.

[0003] At present, most of the axial loading devices in the existing bearing tests use springs to apply preload to the test bearings, or use hydraulic mechanisms to achieve axial loading of the test bearings. When using springs to apply preload to the test bearings, due to errors in the manufacture of the springs, precise control cannot be performed during loading, and it cannot be guaranteed that each spring applies an equal axial force to the test bearings. Using hydraulic mechanisms to load can precisely control the loading force, but the hydraulic mechanisms require a complex hydraulic system. Moreover, when the outer ring of the test bearing and the roller are bonded at high temperature, the axial loading device used in the existing bearing test cannot be separated from the test bearing in time, which will affect the test results. Summary of the invention

[0004] In order to solve the problem of continuous and precise adjustment of axial load within a certain range in bearing tests, the present invention provides an axial loading device for bearing tests. Aiming at the problem that the axial loading device used in the existing bearing tests cannot be separated from the test bearing in time when the outer ring of the test bearing and the roller are glued at high temperature, a clutch unit is arranged in the axial loading device; in order to avoid the axial force applied to the test bearing by the gravity of the bearing seat cover and the outer ring of the test bearing, a lever mechanism is arranged in the axial loading device; and in order to solve the problem that the vibration generated during the test process affects the precise quantitative loading of the axial force, a variable damping unit is arranged.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: an axial loading device for bearing testing, comprising:

[0006] A test bearing unit, used to install and support the test bearing, with a guide sleeve disposed on the outer side of the top end of the test bearing unit;

[0007] The clutch unit comprises a bearing seat cover which is arranged outside the test bearing and is used to apply an axial load force to the test bearing, and a clutch which is slidably connected to the guide sleeve, wherein a mutually cooperating magnetic clutch mechanism is arranged between the bearing seat cover and the clutch, and when the clutch slides upward along the outer wall of the guide sleeve, the bearing seat cover and the clutch can be sucked and connected;

[0008] The loading unit includes a shift fork disposed outside the clutch unit and a driving mechanism capable of driving the shift fork to move up and down, and the shift fork is fixedly connected to the clutch, and the driving mechanism drives the engaged clutch unit to move downward through the shift fork, thereby applying an axial loading force to the test bearing;

[0009] The damping unit has adjustable damping and is connected to one end of the shift fork, and is used to reduce the vibration generated by the shift fork during the upward and downward movement.

[0010] Furthermore, it also includes a lever mechanism, which includes a fork seat for installing and fixing the axial loading device and a plurality of balancing bolts detachably connected to one end of the fork, the two ends of the fork seat are respectively connected to the two fork arms of the fork through cylindrical pins, and a needle bearing is also provided at the connection between the cylindrical pin and the fork arm. By installing a certain number of balancing bolts at one end of the fork, the height of the other end of the fork is adjusted to offset the axial force applied to the test bearing by the gravity of the bearing seat cover and the outer ring of the test bearing.

[0011] Furthermore, the magnetic clutch mechanism is composed of a plurality of armatures and a plurality of permanent magnets which are correspondingly arranged on the relative end faces of the bearing seat cover and the clutch and cooperate with each other. The plurality of permanent magnets are evenly distributed on the end face of the clutch along the circumferential direction, and an adjustment screw for adjusting the height of the permanent magnet is provided at the bottom of each permanent magnet.

[0012] Furthermore, the guide sleeve and the clutch are coaxially arranged and are slidably connected via a linear bearing.

[0013] Furthermore, the damping unit includes a solid shaft, a hollow shaft, and two circular plates with the same structure and arranged up and down, and a plurality of arc-shaped through holes are opened on the end surface of each circular plate, wherein the circular plate at the bottom is connected to one end of the fork through the solid shaft, the outer side of the solid shaft is sleeved with the hollow shaft and the bottom end of the hollow shaft is connected to the circular plate at the top, and the positional relationship of the arc-shaped through holes on the two circular plates is adjusted by rotating the hollow shaft, thereby realizing the adjustment of the damping of the damping unit.

[0014] Furthermore, the driving mechanism includes a pull rod, a pull rod guide, a linear actuator, a tension spring and a force measuring rod. The pull rod is slidably arranged in the pull rod guide, the linear actuator is connected to the lower end of the pull rod and can drive the pull rod to move linearly up and down in the pull rod guide, the lower end of the tension spring is connected to the upper end of the pull rod, the upper end of the tension spring is connected to the lower end of the force measuring rod, and the fork is connected to the upper end of the force measuring rod.

[0015] Furthermore, the bearing seat cover is made of non-ferromagnetic material, the armature is made of ferromagnetic material, and the armature is provided with a thread for mounting in cooperation with the bearing seat cover.

[0016] Furthermore, the test bearing unit includes a test bearing, a shaft and a tapered screw. A threaded through hole matching the threaded portion of the tapered screw is axially opened inside the shaft, and a tapered hole connected to the threaded through hole is opened inside the top end. The shaft has a plurality of rectangular cutouts along the generatrix direction at the tapered hole. The end of the tapered screw has an inclined surface. By continuously screwing the tapered screw into the threaded through hole, the shaft expands at the tapered hole, thereby realizing the loading of the test bearing.

[0017] Furthermore, the test bearing is an angular contact ball bearing, the narrow end of the outer ring of which contacts the shaft shoulder, and the wide end of the outer ring contacts the bearing seat cover.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the clutch unit provided in the present invention can realize that when the test bearing roller is bonded to the outer ring at high temperature, the axial loading mechanism and the test bearing are separated more quickly, and the loading is carried out in the manner of "linear actuator + lever + permanent magnet", so as to achieve the purpose of accurately and continuously adjusting the axial force applied to the test bearing within a larger range. In addition, the present invention is provided with a variable damping mechanism to improve the measurement anti-interference and measurement accuracy of the device, and the present invention can also realize axial loading tests on bearings of various models in a set of devices, and the overall structure is simple and reasonable, and the manufacturing and use costs are low. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the axial loading device for bearing testing of the present invention;

[0020] Figure 2 A top view of an axial loading device for bearing testing according to the present invention;

[0021] Figure 3 for Figure 2 Sectional view along A-A;

[0022] Figure 4 It is a structural schematic diagram of a shift fork in an axial loading device for bearing testing of the present invention;

[0023] Figure 5A schematic diagram of the structure of the fork seat in the axial loading device for the bearing test of the present invention;

[0024] Figure 6 It is a schematic diagram of the structure of the clutch in the axial loading device for bearing testing of the present invention;

[0025] Figure 7 A schematic diagram of the structure of a bearing seat cover in an axial loading device for bearing testing of the present invention;

[0026] Figure 8 It is a schematic diagram of the structure of the central shaft of the axial loading device for bearing testing of the present invention;

[0027] Fig. 9 It is a schematic structural diagram of the axial loading device for bearing testing of the present invention, in which the angle between the top damping plate and the bottom damping plate is 0°;

[0028] Fig.10 It is a schematic structural diagram of the axial loading device for bearing test of the present invention, in which the angle between the top damping plate and the bottom damping plate is 22.5°;

[0029] Fig.11 It is a schematic structural diagram of the axial loading device for bearing testing of the present invention, in which the angle between the top damping plate and the bottom damping plate is 45°;

[0030] Figure numerals: 1. damping cylinder, 2. top damping plate, 3. bottom damping plate, 4. pull rod, 5. pull rod guide, 6. linear actuator, 7. tension spring, 8. force measuring rod, 9. shift fork, 901. oblong through hole, 902. threaded through hole, 903. balance bolt, 904. circular through hole, 10. shift fork seat, 11. cylindrical pin, 12. needle roller bearing, 13. guide sleeve, 14. clutch, 1401. countersunk threaded through hole, 15. linear bearing, 16. bearing seat cover, 17. armature, 18. permanent magnet, 1801. adjustment screw, 19. test bearing, 20. shaft, 21. tapered screw, 22. fiber grating sensor, 23. rectangular cutout, 24. arc-shaped through hole. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] An axial loading device for bearing testing, such as Figure 1-Figure 3As shown, it includes a damping unit, a loading unit, a clutch unit and a test bearing unit;

[0033] Wherein, the damping unit includes a bottom damping plate 3, a top damping plate 2 and a damping cylinder 1, the bottom damping plate 3 includes a first circular plate and a solid shaft coaxially arranged with the first circular plate, the top damping plate 2 includes a second circular plate and a hollow shaft coaxially arranged with the second circular plate, the aperture of the hollow shaft is larger than the diameter of the solid shaft, the length of the hollow shaft is smaller than the length of the solid shaft, and four arc-shaped through holes of the same size are evenly distributed along the circumferential direction on the two circular plates; the top damping plate 2 is arranged above the bottom damping plate 3, and the two are tightly matched, so that the top damping plate 2 can rotate circumferentially around the central axis of the bottom damping plate 3 only under the action of external force; the size of the overlapping part of the long arc-shaped through holes is changed by rotating the top damping plate 2, thereby changing the damping of the damping plate in the oil, specifically: when the two arc-shaped through holes 24 do not overlap, such as Fig.11 As shown, the damping is maximum; when the two arc-shaped through holes 24 overlap half, as shown Fig.10 As shown, the damping is half of that when the two arc-shaped through holes 24 are completely overlapped. Fig. 9 As shown, the damping is minimum. A certain amount of liquid is injected into the damping cylinder, and the lower ends of the two coaxially mounted damping plates are placed in the damping cylinder 1, and connected to the fork 9 in the loading unit through the bottom damping plate 3 and the solid shaft.

[0034] The loading unit includes a pull rod 4, a pull rod guide frame 5, a linear actuator 6, a tension spring 7, a force measuring rod 8 and a fiber optic Bragg grating sensor 22. The pull rod 4 is arranged in the pull rod guide frame 5. The linear actuator 6 is connected to the lower end of the pull rod 4 and drives the pull rod 4 to move linearly up and down in the pull rod guide frame 5. The lower end of the tension spring 7 is connected to the upper end of the pull rod 4, the upper end of the tension spring 7 is connected to the lower end of the force measuring rod 8, the fork 9 is connected to the upper end of the force measuring rod 8, and the fiber optic Bragg grating sensor 22 for measuring axial force is pasted on the force measuring rod 8.

[0035] like Figure 4-Figure 6As shown, two threaded through holes are provided on the fork handle of the shift fork 9, and an oblong through hole 901, a circular through hole 904 and a threaded through hole 902 are respectively provided on the shift fork arm. The threaded through hole 902 provided on the shift fork handle is respectively connected to the upper end of the force measuring rod 8 and the upper end of the bottom damping plate 3. A cylindrical pin 11 is installed in the oblong through hole 901 and is connected to the clutch 14 and the shift fork 9 through the cylindrical pin 11. A needle bearing 12 is installed at the circular through hole 904 on the shift fork arm. Both ends of the shift fork seat 10 are installed on the inner ring of the needle bearing 12 through the cylindrical pin 11, and the shift fork seat 10 is fixedly installed on the bearing test equipment by bolts. A balancing bolt is installed at the threaded through hole 902 on the right side of the shift fork arm. The balancing bolt and the shift fork seat 10 constitute the lever mechanism in the present invention, and the principle is as follows: a certain number of balancing bolts are installed at one end of the shift fork to adjust the height of the other end of the shift fork to offset the axial force applied to the test bearing by the gravity of the bearing seat cover and the outer ring of the test bearing.

[0036] The clutch unit includes a guide sleeve 13, a clutch 14, a linear bearing 15, a bearing seat cover 16, an armature 17 made of ferromagnetic material, and a permanent magnet 18. The guide sleeve 13 is arranged in the fork arm of the fork 9 and is installed above the bearing test equipment. Two circular holes of the same size are arranged on the side of the clutch 14. The circular holes are connected to the fork 9 through a cylindrical pin 11, and the clutch 14 and the fork 9 are concentrically arranged on the outside of the guide sleeve 13, and a radial gap is left between the two. Figure 7 As shown, three countersunk threaded through holes 1401 are respectively provided at the four corners of the top surface of the clutch 14, so that axial preload can be applied to rolling bearings of various types in the test; the bearing seat cover 16 is made of non-ferromagnetic material, which can protect the test bearing and prevent the test bearing from being magnetized and then adsorbing particles, aggravating the wear of the test bearing and affecting the test results; the linear bearing 15 is concentrically arranged between the clutch 14 and the guide sleeve 13, the bearing seat cover 16 is arranged above the clutch 14 and concentric with the clutch 14, and a certain vertical gap is left between the bearing seat cover 16 and the clutch 14 The clutch 14 is spaced apart so that when the shift fork 9 is lifted upward, the clutch 14 can be driven to move upward; the armature 17 is respectively placed in the four threaded through holes 902 arranged on the bearing seat cover 16, and the armature 17 is provided with threads. The permanent magnet 18 is placed in the countersunk threaded through hole 1401, and an adjusting screw 1801 is arranged below the permanent magnet 18 and connected to the clutch 14. The distance between the permanent magnet 18 and the armature 17 is adjusted by rotating the screw so that the magnetic force between each permanent magnet 18 and the armature 17 is equal; when the permanent magnet 18 needs to be taken out, the adjusting screw 1801 is rotated to push the permanent magnet 18 out from the bottom to the top.

[0037] The test bearing unit comprises a test bearing 19, a shaft 20 and a tapered screw 21, as shown in FIG. Figure 8As shown, a threaded through hole matching the threaded portion of the tapered screw 21 is axially opened inside the shaft 20, and a tapered hole connected to the threaded through hole is opened inside the top end. The shaft is provided with a plurality of rectangular cutouts along the generatrix direction at the tapered hole. The end of the tapered screw has an inclined surface. By continuously screwing the tapered screw into the threaded through hole, the shaft expands at the tapered hole, so that the shaft 20 and the test bearing 19 are transitionally matched, thereby realizing the loading of the test bearing. If the test bearing 19 needs to be replaced or removed, the tapered screw 21 can be unscrewed.

[0038] The working principle of the axial loading device is as follows: the axial loading device is installed on the bearing test equipment through the fork seat 10, and the test bearing 19 is concentrically installed in the bearing seat cover 16; the fork 9 is lifted to move the clutch 14 upward, reducing the air gap between the permanent magnet 18 and the armature 17, so that the clutch and the bearing seat cover 16 are attracted to each other by magnetic force, and the spring 7 is in a stretched state at this time; the balance bolt 903 at the right end of the fork is adjusted to make the fork 9 in a balanced state to offset the axial force applied to the test bearing 19 by the gravity of the bearing seat cover 16 and the outer ring of the test bearing 19; the linear actuator 6 is started to make the pull rod 4 drive the fork 9 to move downward, and the clutch 14 connected to the fork 9 drives the bearing seat cover 16 to move downward under the action of the magnetic force of the permanent magnet 18, and the bearing seat cover 16 moves downward to apply axial force to the test bearing 19; the vibration generated in the process of applying the axial force can be mitigated by the damping unit; the applied axial force is measured by the fiber grating sensor 22 and transmitted to The computer ensures that the magnetic force between the permanent magnet 18 and the armature 17 is always greater than the applied axial force; the motor is started to drive the test bearing 19 to rotate, at which time the inner ring of the test bearing 19 rotates and the outer ring is stationary; as the motor speed of the drive shaft increases, the temperature between the rollers of the test bearing 19 and the inner and outer raceways will rise; when the temperature reaches a certain value, the rollers of the test bearing and the inner and outer raceways will produce high-temperature bonding, and the rollers will drive the outer ring of the test bearing to rotate; when the rotational torque generated by the rotation of the outer ring of the test bearing is greater than the shear torque between the permanent magnet and the armature, the permanent magnet 18 in the clutch 14 and the armature 17 in the bearing seat cover 16 are staggered from each other, so that the magnetic force of mutual attraction between the clutch 14 and the bearing seat cover 16 disappears; under the action of the rebound force of the tension spring 7 and the applied axial force, the shift fork 9 drives the clutch 14 to move downward and return to the initial position; the clutch 14 is separated from the bearing seat cover 16, and the axial force applied to the test bearing 19 is unloaded.

[0039] The working process of the present invention is:

[0040] Lift the shift fork 9 upwards, and the clutch 14 moves linearly upwards under the action of the linear bearing 15, reducing the air gap between the permanent magnet 18 and the armature 17, so that the permanent magnet 18 in the clutch 14 and the armature 17 in the bearing seat cover 16 are attracted to each other through magnetic force; adjust the balance bolt 903 at the right end of the shift fork 9 to make the shift fork 9 of the clutch unit in a balanced state, offsetting the axial force exerted on the test bearing 19 by the gravity of the bearing seat cover 16 and the outer ring of the test bearing 19, and at this time, the tension spring 7 in the loading unit is in a stretched state.

[0041] Start the linear actuator 6, which drives the pull rod 4 to move linearly in the pull rod guide 5, causing the shift fork 9 to tend to move downward. The clutch 14 connected to the shift fork 9 drives the bearing seat cover 16 to move downward under the action of the magnetic force of the permanent magnet 18, and the bearing seat cover 16 drives the outer ring of the test bearing 19 to move downward, thereby applying an axial force to the test bearing 19; the vibration generated in the process of applying the axial force can be mitigated by the damping unit, and the size of the overlapping part of the long arc-shaped through hole can be changed by rotating the top damping plate 2, thereby changing the damping of the damping plate in the oil; the applied axial force is measured by the fiber grating sensor 22 and transmitted to the computer, and the quantitative and precise loading of the axial force is adjusted and completed by observing the data transmitted to the computer. At this time, the axial preload force of the test bearing 19 is applied.

[0042] Start the motor to drive the test bearing 19 to rotate. At this time, the inner ring of the test bearing 19 rotates and the outer ring is stationary. As the motor speed increases, the temperature between the rollers of the test bearing 19 and the inner and outer raceways will rise. When the temperature rises to a certain value, the rollers of the test bearing 19 and the inner and outer raceways will produce high-temperature bonding, and the rollers will drive the outer ring of the test bearing 19 to rotate. When the rotational torque generated by the rotation of the outer ring of the test bearing 19 is greater than the shear torque between the permanent magnet 18 and the armature 17, the armature 17 in the bearing seat cover 16 and the permanent magnet 18 in the clutch 14 will be offset from each other, and the magnetic force between the two disappears. The shift fork 9 drives the clutch 14 to move downward rapidly under the action of the rebound force of the tension spring 7 and the downward axial force applied by the linear actuator 6, and the clutch 14 and the bearing seat cover 16 are separated from each other, and the applied axial preload force is unloaded.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An axial loading device for bearing testing, characterized in that: include, A test bearing unit, used to install and support the test bearing, with a guide sleeve disposed on the outer side of the top end of the test bearing unit; The clutch unit comprises a bearing seat cover which is arranged outside the test bearing and is used to apply an axial load force to the test bearing, and a clutch which is slidably connected to the guide sleeve, wherein a mutually cooperating magnetic clutch mechanism is arranged between the bearing seat cover and the clutch, and when the clutch slides upward along the outer wall of the guide sleeve, the bearing seat cover and the clutch can be sucked and connected; The loading unit includes a shift fork disposed outside the clutch unit and a driving mechanism capable of driving the shift fork to move up and down, and the shift fork is fixedly connected to the clutch, and the driving mechanism drives the engaged clutch unit to move downward through the shift fork, thereby applying an axial loading force to the test bearing; A damping unit, whose damping is adjustable and connected to one end of the shift fork, is used to reduce the vibration generated by the shift fork during the upward and downward movement; The test bearing unit comprises a test bearing, a shaft and a tapered screw. A threaded through hole matching the threaded portion of the tapered screw is provided in the interior of the shaft along the axial direction and a tapered hole connected to the threaded through hole is provided in the interior of the top end. The shaft is provided with a plurality of rectangular cutouts along the generatrix direction at the tapered hole. The end of the tapered screw has an inclined surface. By continuously screwing the tapered screw into the threaded through hole, the shaft expands at the tapered hole, thereby realizing the loading of the test bearing. The magnetic clutch mechanism consists of a plurality of armatures and a plurality of permanent magnets which are correspondingly arranged on the bearing seat cover and the relative end faces of the clutch and cooperate with each other. The plurality of permanent magnets are evenly distributed on the end face of the clutch along the circumferential direction, and an adjustment screw for adjusting the height of the permanent magnet is provided at the bottom of each permanent magnet.

2. The axial loading device for bearing testing according to claim 1, characterized in that: It also includes a lever mechanism, which includes a fork seat for installing and fixing the axial loading device and a plurality of balancing bolts detachably connected to one end of the fork, the two ends of the fork seat are respectively connected to the two fork arms of the fork through cylindrical pins, and a needle bearing is also provided at the connection between the cylindrical pin and the fork arm. By installing a certain number of balancing bolts at one end of the fork, the height of the other end of the fork is adjusted to offset the axial force applied to the test bearing by the gravity of the bearing seat cover and the outer ring of the test bearing.

3. The axial loading device for bearing testing according to claim 1, characterized in that: The guide sleeve and the clutch are coaxially arranged and are slidably connected via a linear bearing.

4. The axial loading device for bearing testing according to claim 1, characterized in that: The damping unit includes a solid shaft, a hollow shaft and two circular plates with the same structure and arranged up and down, and a plurality of arc-shaped through holes are opened on the end surface of each circular plate, wherein the circular plate at the bottom is connected to one end of the fork through the solid shaft, the outer side of the solid shaft is sleeved with the hollow shaft and the bottom end of the hollow shaft is connected to the circular plate at the top, and the positional relationship of the arc-shaped through holes on the two circular plates is adjusted by rotating the hollow shaft, thereby realizing the adjustment of the damping of the damping unit.

5. The axial loading device for bearing testing according to claim 1, characterized in that: The driving mechanism includes a pull rod, a pull rod guide, a linear actuator, a tension spring and a force measuring rod. The pull rod is slidably arranged in the pull rod guide. The linear actuator is connected to the lower end of the pull rod and can drive the pull rod to move linearly up and down in the pull rod guide. The lower end of the tension spring is connected to the upper end of the pull rod, and the upper end of the tension spring is connected to the lower end of the force measuring rod. The fork is connected to the upper end of the force measuring rod.

6. An axial loading device for bearing testing according to claim 1, characterized in that: The bearing seat cover is made of non-ferromagnetic material, the armature is made of ferromagnetic material, and the armature is provided with a thread for matching and mounting with the bearing seat cover.

7. An axial loading device for bearing testing according to claim 1, characterized in that: The test bearing is an angular contact ball bearing, the narrow end of the outer ring of which contacts the shaft shoulder, and the wide end of the outer ring contacts the bearing seat cover.

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