Flexible preload structure, test fixture and high-speed bearing testing machine

Abstract

The present application relates to a flexible preload structure, a test fixture and a high-speed bearing tester. The flexible preload structure of the bearing includes a core shaft and a bearing seat sleeved outside the core shaft. The bearing sleeve is sleeved outside the core shaft and the inner ring of the bearing is fixed to the core shaft. The outer sleeve of the bearing is provided with a transition sleeve between the bearing seat and the bearing. The transition sleeve is fixed to the outer ring of the bearing. There is a spacing between the outer peripheral wall of the transition sleeve and the inner peripheral wall of the bearing seat. The bearing seat has a loading ring plate extending to one side of the transition sleeve. There is a spacing between the loading ring plate and the bearing seat, and an elastic member is provided between the loading ring plate and the transition sleeve to force the two to always have a tendency to move away from each other. The present application has a high test accuracy effect on high-speed bearings.

Description

Technical Field

[0001] The present application relates to the field of bearing testing machines, and in particular to a flexible preload structure, a testing fixture, and a high-speed bearing testing machine. Background Art

[0002] The testing machine is a testing device that detects parameters such as the speed and service life of the bearing. It can simulate the actual load of the bearing by radially loading the bearing.

[0003] In today's testing machines, the test bearing is usually installed on a rotating mandrel, with its inner ring fixed to the mandrel and the outer ring confined in a fixed bearing seat. The rotation of the mandrel drives the inner and outer rings of the test bearing to rotate relative to each other. However, since the rolling element does not completely fit the raceway of the inner ring and the raceway of the outer ring during actual use (that is, there is a certain amount of clearance), the rolling element is not in a pure rolling state relative to the inner and outer rings during the rotation of the bearing, and a certain amount of relative sliding will occur. After years of experiments and simulations by professionals in the industry, it was found that the life and maximum speed of the rolling element are closely related to the axial preload of the bearing, and the most suitable preload is to make the rolling element slightly interfere with the inner and outer rings.

[0004] Therefore, in the preload structure of the test bearing, an axial preload force is applied to one side of the test fixture, which is usually applied to the outer ring of the test bearing on one side, and then transmitted to the test bearing on the other side through the inner ring of the bearing to the core shaft to achieve axial preload of the test bearings on both sides.

[0005] However, the traditional preloading method has certain disadvantages. Due to the rigid preloading and the process of transmitting the preloading force through one side, the preloading force of the test bearings on both sides is not exactly the same, which will cause deviations in the test bearings on both sides during the test process (such as life, temperature, speed and other parameters), affecting the actual test results. In addition, since the test bearing needs to be axially loaded, a certain relative displacement needs to occur between the outer ring of the test bearing and the bearing seat, which means that there must always be a certain gap between the outer ring of the test bearing and the bearing seat, that is, a clearance fit connection method. However, during the rotation of the test bearing, its rolling elements will not only roll in theory, but also have a certain relative sliding, which will cause the outer ring of the test bearing to creep during the test, thereby affecting the normal movement of the rollers. At the same time, it will also cause vibration of the outer ring to a certain extent, causing friction and wear between the outer ring and the bearing seat, resulting in temperature rise, which greatly affects the test accuracy. Summary of the invention

[0006] In order to improve the testing accuracy of high-speed bearings, the present application provides a flexible preload structure, a testing fixture and a high-speed bearing testing machine.

[0007] In the first aspect, the present application provides a bearing flexible preload structure adopting the following technical solution:

[0008] A bearing flexible preload structure comprises a core shaft and a bearing seat sleeved outside the core shaft, the bearing sleeve is sleeved outside the core shaft and the inner ring of the bearing is fixed to the core shaft, the bearing outer sleeve is provided with a transition sleeve located between the bearing seat and the outer ring of the bearing, the transition sleeve is fixed to the outer ring of the bearing, there is a spacing between the outer peripheral wall of the transition sleeve and the inner peripheral wall of the bearing seat, the bearing seat has a loading ring plate extending to one side of the transition sleeve, there is a spacing between the loading ring plate and the bearing seat, and an elastic member is provided between the loading ring plate and the transition sleeve to force the two to always have a tendency to move away from each other.

[0009] By adopting the above technical solution, firstly, the spacing between the transition sleeve and the loading ring plate enables the transition sleeve to have a certain axial movement clearance, and when the loading ring plate is fixed, since the transition sleeve and the loading ring plate are not in contact, the axial load applied by the transition sleeve to the outer ring of the bearing can be approximately supported by the elastic modulus of the elastic member, so that the bearings on both sides of the bearing tester can have approximately the same axial preload, reducing the gap between the two stations, and reducing the situation where the bearing on one side is shut down due to premature failure. In addition, since the transition sleeve and the outer ring of the bearing are fixed, the two can be approximately regarded as a whole, so the overall quality will also be improved, so when the outer ring of the bearing has a tendency to creep, the angle of its overall deviation will be smaller. On the other hand, since the transition sleeve is relatively thick as a whole, the movement between the transition sleeve and the bearing seat has a smaller impact on the outer ring of the bearing, reducing the temperature rise caused by the bearing in a high-speed test environment, thereby effectively improving the accuracy of the test process.

[0010] Preferably, the elastic member includes a compression spring, and a plurality of the compression springs are arranged in the circumferential direction of the transition sleeve. The loading ring plate is provided with a first spring groove for one end of the compression spring to pass through, and the transition sleeve is provided with a second spring groove for the other end of the compression spring to pass through.

[0011] By adopting the above technical solution, the first spring groove and the second spring groove are provided to limit the compression spring, thereby improving the connection strength of the compression spring between the loading ring plate and the transition sleeve.

[0012] Preferably, the first spring groove or the second spring groove is an annular groove.

[0013] By adopting the above technical solution, since the transition sleeve still undergoes a certain circumferential creep, the setting of the annular groove allows the compression spring to undergo a certain circumferential deviation in the annular groove, thereby preventing the compression spring from twisting or even failing.

[0014] Preferably, the depth of the first spring groove is smaller than the depth of the second spring groove.

[0015] Preferably, the transition sleeve is interference fit with the outer ring of the bearing, and the transition sleeve has a limiting portion extending to one side of the bearing, and the limiting portion is located between the bearing and the loading ring plate.

[0016] By adopting the above technical solution, the interference fit method facilitates the installation of the transition sleeve and the bearing. At the same time, the setting of the limit part can also improve the connection strength with the bearing under the drive of the axial preload, and reduce the displacement and slippage between the outer ring of the bearing and the transition sleeve.

[0017] Preferably, the bearing seat includes a base to which the loading ring plate is detachably connected.

[0018] By adopting the above technical solution, the detachable connection method facilitates the installation of the elastic member and the transition sleeve into the bearing seat, thereby improving the assembly efficiency.

[0019] Preferably, two transition sleeves and two bearings are provided, a first spacer sleeve is provided between the inner rings of the two bearings and is respectively pressed against the inner rings of the two bearings, there is a spacing between the two transition sleeves, and two loading ring plates are provided on the bearing seat and are located on two sides opposite to each other of the two transition sleeves.

[0020] By adopting the above technical solution, this setting is usually applied to the test bearing of the bearing tester. Since the distance between the two test bearings is relatively close, the two test bearings can be flexibly preloaded in this way. At the same time, the setting of the two elastic members can also make the axial preload of the two test bearings the same to a certain extent, thereby improving the life of the test bearing.

[0021] Preferably, abutment surfaces are provided on the sides of the two transition sleeves that are close to each other, and the two abutment surfaces are spliced ​​together to form an abutment plane for the loading head of the radial loading mechanism to abut, and the two abutment surfaces are coplanar and perpendicular to the axial direction of the loading head of the radial loading mechanism.

[0022] By adopting the above technical solution, the setting of the abutting plane makes it difficult for the loading head of the radial loading mechanism to slip when abutting against it, thereby improving the stability during radial loading.

[0023] In the second aspect, a bearing testing tool provided in the present application adopts the following technical solution:

[0024] A bearing testing tool comprises the above-mentioned flexible preload structure.

[0025] In the third aspect, the present application provides a high-speed bearing testing machine adopting the following technical solution:

[0026] A high-speed bearing testing machine, comprising a bearing testing tool, a driving mechanism coaxially arranged with the bearing testing tool and located at one end thereof, and an axial loading mechanism located at the other axial end of the bearing testing tool, wherein the bearing testing tool comprises a core shaft and two bearing seats, and the two ends of the core shaft are respectively fixed with a test bearing correspondingly inserted in the bearing seat, the test bearing is preloaded by the above-mentioned flexible preload structure, and two loading ring plates are respectively located on two opposite sides of the test bearings at the two ends;

[0027] Wherein, the axial loading mechanism is used to axially load the outer ring of the test bearing on one side.

[0028] By adopting the above-mentioned technical solution, when the axial loading mechanism loads the outer ring of the test bearing in the test bearing station on one side, the outer ring of the test bearing on this side will tend to deviate away from the axial loading mechanism, and drive the core shaft and the two test bearings on the core shaft to have a slight deviation away from the axial loading mechanism, and compress the compression spring on the other side to provide a greater elastic force, thereby synchronously loading the test bearing on the side close to the driving mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the high-speed bearing testing machine in Example 1 of the present application.

[0030] Figure 2 yes Figure 1 Enlarged schematic diagram of part A.

[0031] Figure 3 It is a structural schematic diagram of the test bearing station in Example 1 of the present application.

[0032] Figure 4 It is a structural schematic diagram of the test bearing station in Example 2 of the present application.

[0033] Explanation of the accompanying reference numerals: 1. testing machine base; 2. bearing test fixture; 3. driving mechanism; 4. axial loading mechanism; 21. test bearing station; 22. test bearing station; 23. spindle; 5. bearing seat; 24. fixing seat; 6. test bearing; 25. locking nut; 7. transition sleeve; 71. limiting portion; 51. loading ring plate; 8. elastic member; 41. loading end cover; 511. first spring groove; 72. second spring groove; 9. test bearing; 10. first spacer sleeve; 11. second spacer sleeve; 52. base; 12. abutment surface; 13. preload spring; 14. limiting plate. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-4 This application is described in further detail.

[0035] Embodiment 1:

[0036] The present application embodiment discloses a high-speed bearing testing machine. Figure 1 The high-speed bearing tester includes a tester base 1, a bearing test fixture 2 fixed on the tester base 1, a driving mechanism 3 coaxially arranged with the bearing test fixture 2 and located at one end thereof, an axial loading mechanism 4 located at the other axial end of the bearing test fixture 2, and a radial loading mechanism (not shown) arranged horizontally and used to radially load the bearing test fixture 2. The test bearing 6 to be tested is arranged in the bearing test fixture 2 and fixed by the bearing test fixture 2, and the simulated working condition of the test bearing 6 under the condition of axial loading is simulated by the setting of the axial loading mechanism 4, and the simulated working condition of the test bearing 6 under the condition of rotation with load is simulated by the loading of the radial loading mechanism.

[0037] The bearing testing tool 2 includes a test bearing station 21, a test bearing station 22 located on both sides of the test bearing station 21, and a core shaft 23 that penetrates the test bearing station 22 and the test bearing station 21 and is linked to the driving mechanism 3, wherein the test bearing stations 22 on both sides are fixed on the testing machine base 1, and the loading head of the radial loading mechanism acts on the test bearing station 21. Also because of the setting of the radial loading mechanism, the test bearing station 21 can also be relatively stably fixed on the testing machine base 1.

[0038] Reference Figure 1 and Figure 2 The test bearing station 22 has a bearing seat 5 and a fixing seat 24 which is arranged on the testing machine base 1 and is used to fix the bearing seat 5. The core shaft 23 is passed through the bearing seat 5. The test bearing 6 is sleeved on the core shaft 23 and is located between the core shaft 23 and the bearing seat 5. The test bearing 6 is pre-tightened in the test bearing station 22 through a flexible pre-tightening structure.

[0039] Specifically, the inner ring of the test bearing 6 is fixed to the inner ring by a locking nut 25, so as to realize the synchronous rotation of the inner ring of the test bearing 6 and the core shaft 23. The outer sleeve of the test bearing 6 is provided with a transition sleeve 7 located between the bearing seat 5 and the bearing, and the transition sleeve 7 is fixedly connected with the outer ring of the test bearing 6 by an interference fit connection mode, and the transition sleeve 7 has a limit portion 71 extending to one side of the test bearing 6 and abutting against the outer ring of the test bearing 6. The bearing seat 5 has a loading ring plate 51 extending to one side of the transition sleeve 7, and the limit portion 71 is located between the loading ring plate 51 and the outer ring of the test bearing 6, and there is a gap δ between the loading ring plate 51 and the transition sleeve 7, and there is a spacing α between the outer peripheral wall of the transition sleeve 7 and the inner peripheral wall of the bearing seat 5. An elastic member 8 is provided between the loading ring plate 51 and the transition sleeve 7, and the elastic member 8 forces the transition sleeve 7 to always have a tendency to move away from the loading ring plate 51. The purpose of flexible preload is achieved through the interaction of the transition sleeve 7, the elastic member 8, the core shaft 23 and the bearing seat 5.

[0040] Among them, the setting of the gap α allows the transition sleeve 7 to have a certain axial movement in the bearing seat 5, and when the transition sleeve 7 heats up and expands, the gap α always exists. The setting of the gap δ allows a certain amount of movement between the transition sleeve 7 and the loading ring plate 51 after balance, which can also play the role of floating installation to a certain extent.

[0041] The test bearing stations 22 on both sides are symmetrically arranged relative to the vertical plane of the connecting line, so when the overall balance is achieved, it can be found that due to the existence of the gap δ, the axial preload force of the outer ring of the test bearing 6 is completely provided by the elastic member 8, wherein the elastic member 8 is selected as a compression spring in this embodiment, so it can be known that the compression amount of the compression spring can be changed by changing the gap δ, thereby adjusting the axial preload force on the outer ring of the test bearing 6. However, since the core shaft 23 has a certain degree of floating, the preload amount of the test bearing 6 on both sides can be kept the same, thereby maintaining the consistency of the preload of the test bearing 6 in the test bearing stations 22 on both sides to a certain extent.

[0042] However, when the axial loading mechanism 4 loads the outer ring of the test bearing 6 in the test bearing station 22 on one side, the outer ring of the test bearing 6 on this side tends to deviate away from the axial loading mechanism 4, and drives the mandrel 23 and the two test bearings 6 on the mandrel 23 to have a slight deviation away from the axial loading mechanism 4, and compresses the compression spring on the other side to provide a greater elastic force, thereby synchronously loading the test bearing 6 close to the driving mechanism 3. Among them, the loading head of the axial loading mechanism 4 acts on a loading end cover 41, and the loading end cover 41 directly abuts against the outer ring of the test bearing 6, thereby realizing the axial loading of the test bearing 6 by the axial loading mechanism 4.

[0043] At the same time, since the transition sleeve 7 and the outer ring of the test bearing 6 are fixed, the two can be approximately regarded as a whole, so their overall mass will also increase, and thus their inertia will also increase. Therefore, when the outer ring of the bearing has a tendency to creep, the angle of its overall deviation will be smaller. On the other hand, since the transition sleeve 7 is relatively thick as a whole, the impact of the movement between the transition sleeve 7 and the bearing seat 5 on the outer ring of the test bearing 6 is also small. When the outer peripheral wall of the transition sleeve 7 and the inner peripheral wall of the bearing seat 5 creep and rub relative to each other and generate heat, only a small part of the generated heat will be transferred to the test bearing 6, reducing the temperature rise caused by the test bearing 6 in the high-speed test environment, and effectively improving the stability and accuracy of the test bearing 6 during the test process.

[0044] Furthermore, at least three compression springs are evenly arranged around the transition sleeve 7. The loading ring plate 51 is provided with a first spring groove 511 for one end of the compression spring to pass through, and the transition sleeve 7 is provided with a second spring groove 72 for the other end of the compression spring to pass through. However, since the transition sleeve 7 may move in a certain circumferential direction, any one of the first spring groove 511 or the second spring groove 72 may be designed as an annular groove. When the transition sleeve 7 moves in a circumferential direction, the compression spring may slide in a circumferential direction in the spring groove which is an annular groove, thereby slowing down the torsion of the compression spring. However, the first spring groove 511 and the second spring groove 72 may not be annular grooves, and when the transition sleeve 7 has a slight circumferential displacement, the radially torsion compression spring may provide a compensating force to prevent the transition sleeve 7 from continuing to deflect in the same direction. Furthermore, the depth of the first spring groove 511 is less than the depth of the second spring groove 72, so that the compression spring may be pre-installed on the second spring groove 72 for easy assembly.

[0045] Reference Figure 1 and Figure 3 Based on the same inventive concept, the test bearing station 21 can also be preloaded with the same flexible preload structure. Specifically, it includes a bearing seat 5 and two transition sleeves 7. The test bearing 9 has two and is sleeved on the core shaft 23. The two transition sleeves 7 are interference-fitted on the outer ring of the test bearing 9 one by one. A first spacer sleeve 10 is provided between the inner rings of the two test bearings 9, which is respectively pressed against the inner rings of the two test bearings 9. A second spacer sleeve 11 is provided between the test bearing 9 and the adjacent test bearing 6, which is respectively pressed against the inner ring of the test bearing 9 and the inner ring of the test bearing 6. The inner rings of the test bearing 9 and the inner ring of the test bearing 6 are relatively fixed through the locking nuts 25 at both ends of the core shaft 23.

[0046] Among them, two loading ring plates 51 are arranged on the bearing seat 5, and the two loading ring plates 51 are respectively located on the two sides of the transition sleeve 7 which are away from each other. Elastic parts 8 for pre-tightening are respectively arranged between the two loading ring plates 51 and the adjacent transition sleeves 7, and there is always a certain gap between the two transition sleeves 7.

[0047] It should be noted that in the test bearing station 21, a flexible preload structure formed between a set of transition sleeves 7, elastic members 8 and a loading ring plate 51 is the same as the flexible preload structure in the test bearing station 22. By adjusting the elastic modulus of the two compression springs in the test bearing station 21 and the distance between the springs and the loading ring plate 51, the two test bearings 9 can be kept under an approximately equal preload force.

[0048] In order to achieve installation, the bearing seat 5 can be configured in a split configuration, that is, it includes a loading ring plate 51 and a base 52 for detachably connecting the loading ring plate 51. The base 52 is sleeved outside the companion test bearing 9. The split bearing seat 5 is not limited to the configuration at the companion test bearing station 21. The bearing seat 5 at the test bearing station 22 can also be arranged in this manner to facilitate installation, which will not be described in detail here.

[0049] At the same time, the base 52 may also have a built-in cooling water chamber to further reduce the heat generated by friction between the transition sleeve 7 and the base 52 and further reduce the temperature of the test bearing 9, thereby increasing the life of the test bearing 9. It should be noted that the life of the test bearing 9 needs to be greater than the life of the test bearing 6 to avoid downtime due to failure of the test bearing 9.

[0050] In addition, in order to improve the stability of the loading head of the radial loading mechanism during the process of loading the test bearing 9, abutment surfaces 12 are provided on the sides of the two transition sleeves 7 that are close to each other. The two abutment surfaces 12 are spliced ​​together to form an abutment plane for the loading head of the radial loading mechanism to abut. The two abutment surfaces 12 are coplanar and the formed abutment plane is perpendicular to the axial direction of the loading head of the radial loading mechanism, so that the radial loading mechanism can stably realize radial loading.

[0051] The implementation principle of the high-speed bearing testing machine in the embodiment of the present application is: through the setting of a flexible preload structure, the preload amount of the bearing in each workstation and the uniformity of loading are guaranteed, and the influence of creep on the bearing is reduced, thereby improving the accuracy of the high-speed bearing testing machine when testing the bearing.

[0052] Embodiment 2:

[0053] The difference between this embodiment and embodiment 1 is that the preload structure of the accompanying test bearing station 21 is different. Figure 4The bearing seat 5 is sleeved outside the two test bearings 9 and limit plates 14 for limiting the test bearings 9 are fixed on both sides of the bearing seat 5. The inner rings of the two test bearings 9 are separated by a first spacer sleeve 10 and abut against the first spacer sleeve 10 at the same time. A preload spring 13 located between the two test bearings 9 is also sleeved on the core shaft 23. The two ends of the preload spring 13 abut against the outer rings of the two test bearings 9 respectively. The elastic force of the preload spring 13 is used to push the outer rings of the two test bearings 9 in opposite directions and realize preload.

[0054] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A bearing flexible preload structure, comprising a core shaft (23) and a bearing seat (5) sleeved outside the core shaft (23), wherein the bearing is sleeved outside the core shaft (23) and the inner ring of the bearing is fixed to the core shaft (23), characterized in that: The bearing outer sleeve is provided with a transition sleeve (7) located between the bearing seat (5) and the bearing, the transition sleeve (7) is fixed to the outer ring of the bearing, there is a gap between the outer peripheral wall of the transition sleeve (7) and the inner peripheral wall of the bearing seat (5), the bearing seat (5) has a loading ring plate (51) extending to one side of the transition sleeve (7), there is a gap between the loading ring plate (51) and the bearing seat (5), and an elastic member (8) is provided between the loading ring plate (51) and the transition sleeve (7) to force the two to always have a tendency to move away from each other; The transition sleeves (7) and the bearings are both provided with two, a first spacer sleeve (10) is provided between the inner rings of the two bearings and is respectively pressed against the inner rings of the two bearings, a spacing is provided between the two transition sleeves (7), and the loading ring plates (51) are provided on the bearing seat (5) and are located on two sides of the two transition sleeves (7) that are away from each other; Abutment surfaces (12) are provided on the sides of the two transition sleeves (7) close to each other, and the two abutment surfaces (12) are spliced ​​together to form an abutment plane for a loading head of the radial loading mechanism to abut against, and the two abutment surfaces (12) are coplanar and perpendicular to the axial direction of the loading head of the radial loading mechanism; The elastic member (8) comprises a compression spring, a plurality of the compression springs are arranged in the circumferential direction of the transition sleeve (7), the loading ring plate (51) is provided with a first spring groove (511) for one end of the compression spring to pass through, and the transition sleeve (7) is provided with a second spring groove (72) for the other end of the compression spring to pass through; The first spring groove (511) or the second spring groove (72) is an annular groove; The depth of the first spring groove (511) is smaller than the depth of the second spring groove (72).

2. The bearing flexible preload structure according to claim 1 is characterized in that: The transition sleeve (7) is interference-fitted with the outer ring of the bearing, and the transition sleeve (7) has a limiting portion (71) extending to one side of the bearing, and the limiting portion (71) is located between the bearing and the loading ring plate (51).

3. The bearing flexible preload structure according to claim 1 is characterized in that: The bearing seat (5) comprises a base (52) to which a loading ring plate (51) is detachably connected.

4. A bearing testing tool, characterized in that: It comprises the flexible pre-tightening structure as described in any one of claims 1 to 3.

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