A bearing friction torque test tool

Abstract

The application belongs to the technical field of bearing test, and particularly relates to a bearing friction torque test tool, which comprises a base, a test table, a test shaft and a test motor. The test table is fixed on the top of the base, the test shaft is rotationally arranged on the surface of the test table, the test motor is fixed on the bottom of the test table and is in transmission connection with the test shaft, and the tool further comprises a dynamic torque sensor, a supporting sleeve, a loading sleeve, a loading wheel, a loading assembly and a clamping unit. The dynamic torque sensor is fixed on the upper end of the test table, and the detection end of the dynamic torque sensor is in transmission connection with the test shaft. The tool can realize dynamic and static friction torque test of bearings under radial partial load working conditions, the test data is more consistent with the real working performance of the bearings, the clamping is convenient, the error caused by the inherent friction torque of the device itself is removed, and the test result is more stable.

Description

Technical Field

[0001] This invention belongs to the field of bearing testing technology, and in particular relates to a bearing friction torque testing fixture. Background Technology

[0002] Bearings are core components of various precision machinery and transmission equipment. Their friction torque performance directly determines the stability of equipment start-up and shutdown, operating energy consumption and service life. In order to accurately determine the bearing assembly quality, lubrication status and transmission performance, and avoid faults such as jamming, abnormal temperature rise and excessive power consumption, it is necessary to accurately detect the bearing friction torque.

[0003] Currently, conventional fixtures for testing bearing friction torque mainly involve clamping the bearing with a positioning structure, fixing the outer ring of the bearing, and driving the inner ring to rotate at a constant speed. A torque sensor is then used to collect the friction torque data of the bearing during steady-state operation, thereby determining whether the bearing's friction performance meets the standards. However, existing testing technologies are mostly based on the ideal working condition of bearings being coaxially unloaded and uniformly stressed. This deviates significantly from the actual service condition of bearings. When bearings are assembled and used in a machine, the drive shaft generally needs to be equipped with functional components such as impellers, gears, and transmission supports. These components have their own fixed weight, and after assembly, they will exert a continuous radial off-center load on the bearing. This causes the bearing to always exhibit an uneven stress state during operation, with a larger load in the lower half and a smaller load in the upper half. This directly leads to changes in the local frictional resistance between the bearing rolling elements and the raceway, and the torque characteristics are significantly different from the ideal uniform load condition. As a result, the test results are not consistent with reality, and the test effect is poor. Summary of the Invention

[0004] The purpose of this invention is to address the above-mentioned problems by providing a bearing friction torque testing fixture that can simulate the radial off-center load during actual bearing operation, making the test results more consistent with reality.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a bearing friction torque testing fixture, comprising a base, a test platform, a test shaft, and a test motor; the test platform is fixed on the top of the base, the test shaft is rotatably disposed on the surface of the test platform, the test motor is fixed on the bottom of the test platform and is connected to the test shaft for transmission, and further comprising: a dynamic torque sensor, a support sleeve, a loading sleeve, a loading wheel, a loading assembly, and a clamping unit; The dynamic torque sensor is fixed at the upper end of the test bench, and the detection end of the dynamic torque sensor is connected to the test shaft drive. The support sleeve is fixedly sleeved to the shaft wall of the test shaft; the loading sleeve is coaxially sleeved on the outside of the support sleeve and fixedly connected to the test bench; the loading assembly is installed on the side wall of the loading sleeve; the loading wheel is installed on the detection end of the loading assembly, and the wheel wall of the loading wheel is in contact with the outer side wall of the support sleeve. The clamping unit is mounted on top of the test shaft and is used to mount the bearing to be tested.

[0006] In the aforementioned bearing friction torque testing fixture, the loading assembly includes a loading cylinder, a first pressure sensor, and a mounting plate; the loading cylinder is fixedly inserted into the side wall of the loading sleeve; the first pressure sensor is fixed to the movable end of the loading cylinder; the mounting plate is fixed to the detection end of the first pressure sensor, and the loading wheel is fixed to the side wall of the mounting plate.

[0007] In the aforementioned bearing friction torque testing fixture, the clamping unit includes an inner ring lower clamping plate, an inner ring upper clamping plate, a clamping drive assembly, an outer ring support groove ring, an outer ring arc-shaped clamping block, a positioning mechanism, and a transmission assembly. The lower inner ring clamp is detachably mounted on the top of the test shaft; the upper inner ring clamp is coaxially positioned above the lower inner ring clamp and mounted on the drive end of the clamping drive assembly, which is mounted on the upper surface of the test bench; the outer ring support groove ring is sleeved on the outside of the lower inner ring clamp, and the inner ring wall of the outer ring support groove ring has an annular stepped groove; the outer ring arc-shaped clamp is mounted on the drive end of the clamping drive assembly; the positioning mechanism and the transmission assembly are both located between the lower inner ring clamp and the upper inner ring clamp, the positioning mechanism is used to position the bearing to be tested, and the lower inner ring clamp is connected to the upper inner ring clamp via the transmission assembly.

[0008] In the aforementioned bearing friction torque testing fixture, the clamping drive assembly includes a mounting frame, a clamping cylinder, a clamping seat, and a rotating shaft; the mounting frame is fixed to the upper surface of the test bench; the clamping cylinder is fixedly inserted through the upper surface of the mounting frame; the clamping seat is fixed to the drive end of the clamping cylinder; the rotating shaft is rotatably disposed at the bottom of the clamping seat, and the inner ring upper clamping plate is detachably mounted at the bottom of the rotating shaft; the outer ring arc-shaped clamping block is detachably mounted at the bottom of the clamping seat and corresponds to the position of the annular stepped groove.

[0009] In the aforementioned bearing friction torque testing fixture, the positioning mechanism includes multiple positioning blocks, multiple springs, and multiple extrusion wheels; the upper surface of the inner ring lower clamping plate is provided with multiple annularly distributed sliding grooves, the positioning blocks are slidably connected to the sliding grooves, and the side of the positioning blocks near the axis of the inner ring lower clamping plate is provided with an inclined extrusion ramp; the springs are fixed between the side wall of the positioning blocks and the groove wall of the sliding grooves; the extrusion wheels are fixed at the bottom of the inner ring upper clamping plate, and the extrusion wheels are positioned above the extrusion ramps, the extrusion wheels push the positioning blocks against the inner ring side wall of the bearing to be tested through the extrusion ramps.

[0010] In the aforementioned bearing friction torque testing fixture, the transmission assembly includes a spline shaft and a spline sleeve; the spline shaft is fixed to the bottom of the inner ring upper clamping plate; the spline sleeve is fixed to the upper surface of the inner ring lower clamping plate, and after the spline shaft is inserted into the spline sleeve, the inner ring lower clamping plate drives the inner ring upper clamping plate to rotate through the spline sleeve and the spline shaft.

[0011] In the aforementioned bearing friction torque testing fixture, a gear ring is fixedly sleeved on the outer wall of the support sleeve; a rack matching the gear ring is provided on the inner side of the loading sleeve; and a horizontal drive assembly for driving the rack to move is installed on the loading sleeve.

[0012] In the aforementioned bearing friction torque testing fixture, the horizontal drive assembly includes a horizontal hydraulic cylinder, a second pressure sensor, and a connecting column; both side walls of the loading sleeve are provided with grooves corresponding to the rack position, and the horizontal hydraulic cylinder is fixed inside one of the grooves; the second pressure sensor is fixed to the drive end of the horizontal hydraulic cylinder; the connecting column is fixed to the detection end of the second pressure sensor, and the connecting column is fixedly connected to the rack.

[0013] Compared with existing technologies, the present invention has the following advantages: 1. This invention, through the setup of a base, test platform, test shaft, test motor, dynamic torque sensor, and clamping unit, enables the bearing under test to be installed at the clamping unit, and the test motor drives the test shaft to complete the dynamic friction torque test of the bearing under test. In addition, with the setup of a support sleeve, loading sleeve, loading wheel, and loading assembly, a radial off-center load can be applied to the test shaft during the dynamic friction torque test of the bearing under test, thereby simulating the radial off-center load that the bearing is subjected to during actual operation, so as to test the actual friction torque of the bearing under the action of radial off-center load, making the test results more in line with reality.

[0014] 2. The positioning mechanism of this invention enables the inner ring upper clamping plate to drive the extrusion wheel downward when the bearing under test is clamped, so that the positioning block pushes the bearing under test to automatically center and return to its position. On the one hand, it can reduce the accuracy requirements when initially installing the bearing under test. On the other hand, it can ensure that the bearing under test and the test shaft remain coaxial, and minimize the error caused by the misalignment of the two axes to the test results. At the same time, the positioning block can more stably transmit the radial off-center load on the test bearing to the bearing under test, ensuring the radial loading effect.

[0015] 3. The present invention, through its transmission component, can pre-connect the upper inner ring clamping plate and the lower inner ring clamping plate when testing the bearing under test, thereby completing the friction torque detection in the state where the bearing under test is not installed. It collects the inherent friction torque of the device itself, minimizing the interference of the tooling itself on the test results of the bearing friction torque, which helps to improve the test accuracy of the dynamic friction torque of the bearing under test. Furthermore, through the transmission component, the driving force of the test shaft can be stably transmitted to the upper inner ring clamping plate, thereby making the rotation of the inner ring of the bearing under test more stable and further improving the test stability.

[0016] 4. The present invention, through the setting of gear ring, rack, and horizontal drive assembly, can drive the rack to move using the horizontal drive assembly, so that the gear ring applies rotational driving force to the test shaft through the loading sleeve. With the cooperation of the second pressure sensor, it can perform static friction torque test on the bearing under test. Dynamic friction torque and static friction torque test can be completed in one clamping. It is suitable for bearings with special testing requirements, such as damping bearings. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a bearing friction torque testing fixture provided by the present invention; Figure 2 This is a bottom view of the test platform provided by the present invention. Figure 3 This is a schematic diagram of the internal structure of the support sleeve provided by the present invention; Figure 4 This is a schematic diagram of the installation of the bearing to be tested provided by the present invention; Figure 5 This is a schematic diagram of the inner ring lower clamping plate provided by the present invention; Figure 6 This is a schematic diagram of the structure of the inner ring upper clamping plate provided by the present invention; Figure 7 This is a bottom view of the internal structure of the support sleeve provided by the present invention.

[0018] In the diagram: 1. Base; 2. Test bench; 3. Test shaft; 4. Test motor; 5. Dynamic torque sensor; 6. Support sleeve; 7. Loading sleeve; 8. Loading wheel; 9. Loading assembly; 91. Loading cylinder; 92. First pressure sensor; 93. Mounting plate; 10. Clamping unit; 101. Inner ring lower clamping plate; 102. Inner ring upper clamping plate; 103. Outer ring support groove ring; 104. Outer ring arc-shaped clamping block; 105. Annular stepped groove; 11. Clamping drive assembly; 111. Installation 112. Frame; 113. Clamping cylinder; 114. Mounting seat; 12. Rotating shaft; 12. Positioning mechanism; 121. Positioning block; 122. Spring; 123. Extrusion wheel; 124. Slide groove; 125. Extrusion ramp; 13. Transmission assembly; 131. Splined shaft; 132. Splined sleeve; 14. Gear ring; 15. Rack; 16. Horizontal drive assembly; 161. Horizontal cylinder; 162. Second pressure sensor; 163. Connecting column; 164. Groove; 17. Bearing to be tested. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] like Figures 1-2 As shown, a bearing friction torque testing fixture includes a base 1, a test platform 2, a test shaft 3, and a test motor 4. The test platform 2 is fixed to the top of the base 1, the test shaft 3 is rotatably mounted on the surface of the test platform 2, and the test motor 4 is fixed to the bottom of the test platform 2 and is drivenly connected to the test shaft 3. An angle encoder (not shown) is installed at the output end of the test motor 4 to monitor the rotation angle of the test shaft 3. The device also includes a dynamic torque sensor 5, a support sleeve 6, a loading sleeve 7, a loading wheel 8, a loading assembly 9, a clamping unit 10, and a PLC controller. The dynamic torque sensor 5 is fixed to the upper end of the test platform 2, and the detection end of the dynamic torque sensor 5 is drivenly connected to the test shaft 3. Sensor 5 acquires the micro-deformation signal of the elastic shaft through an internal strain bridge, and calculates the torque value in real time based on the linear correspondence between torque and strain, with a sampling frequency of up to 100Hz; support sleeve 6 is fixedly sleeved to the shaft wall of test shaft 3; loading sleeve 7 is coaxially sleeved on the outside of support sleeve 6 and fixedly connected to test platform 2; loading assembly 9 is installed on the side wall of loading sleeve 7; loading wheel 8 is installed on the detection end of loading assembly 9, and the wheel wall of loading wheel 8 is in contact with the outer side wall of support sleeve 6; clamping unit 10 is installed on the top of test shaft 3, and clamping unit 10 is used to install the bearing 17 to be tested; PLC controller is used to control the operation of various electrical control components of the device and read the values ​​of sensors such as dynamic torque sensor 5.

[0021] In actual testing, in this embodiment, the bearing under test 17 is installed through the clamping unit 10. The loading component 9 applies a radial off-center load pressure perpendicular to the axis of the test shaft 3 to the support sleeve 6 through the loading wheel 8. The support sleeve 6 transmits this radial off-center load pressure to the bearing under test 17 through the test shaft 3, thereby creating a non-uniform radial force state between the inner and outer rings of the bearing under test 17. This simulates the real off-center load condition of the bearing under test 17 during the use of the whole machine due to its own weight, assembly eccentricity, and load offset. Subsequently, the test motor 4 drives the test shaft 3, and the dynamic torque sensor 5 detects the friction torque of the bearing under test 17 under radial off-center load pressure, making the test results more consistent with reality.

[0022] like Figures 2-3 As shown, in this embodiment, the loading component 9 includes a loading cylinder 91, a first pressure sensor 92, and a mounting plate 93; the loading cylinder 91 is fixedly inserted into the side wall of the loading sleeve 7; the first pressure sensor 92 is fixed to the movable end of the loading cylinder 91; the mounting plate 93 is fixed to the detection end of the first pressure sensor 92, and the loading wheel 8 is fixed to the side wall of the mounting plate 93.

[0023] In actual testing, this embodiment applies pressure to the first pressure sensor 92 through the loading cylinder 91. The first pressure sensor 92 then transmits the pressure to the loading wheel 8 through the mounting plate 93, thereby applying radial off-center load pressure to the loading wheel 8. The required value of the simulated radial off-center load pressure is preset by the PLC controller. After the first pressure sensor 92 detects that the set threshold has been reached, it sends an electrical signal back to the PLC controller. The PLC controller then controls the loading cylinder 91 to stop working, improving the convenience and accuracy of the radial off-center load pressure application operation.

[0024] like Figure 1 , Figure 2 , Figures 4-6 As shown, in this embodiment, the clamping unit 10 further includes an inner ring lower clamping plate 101, an inner ring upper clamping plate 102, a clamping drive assembly 11, an outer ring support groove ring 103, an outer ring arc-shaped clamping block 104, a positioning mechanism 12, and a transmission assembly 13. The inner ring lower clamping plate 101 is detachably installed on the top of the test shaft 3; the inner ring upper clamping plate 102 is coaxially arranged above the inner ring lower clamping plate 101, and the inner ring upper clamping plate 102 is installed on the driving end of the clamping drive assembly 11, which is installed on the upper surface of the test bench 2; the outer ring support groove ring 103 is sleeved on the outside of the inner ring lower clamping plate 101, and the inner ring wall of the outer ring support groove ring 103 is provided with an annular stepped groove 105; the outer ring arc-shaped clamping block 104 is installed on the driving end of the clamping drive assembly 11; the positioning mechanism 12 and the transmission assembly 13 are both arranged between the inner ring lower clamping plate 101 and the inner ring upper clamping plate 102. The positioning mechanism 12 is used to position the bearing 17 to be tested, and the inner ring lower clamping plate 101 is connected to the inner ring upper clamping plate 102 through the transmission assembly 13.

[0025] In actual testing, this embodiment allows the bearing 17 to be placed in the outer ring support groove ring 103. The outer ring arc-shaped clamping block 104 applies pressure from above the bearing 17 to fix the outer ring of the bearing 17 relative to the outer ring support groove ring 103 and the outer ring arc-shaped clamping block 104. The inner ring lower clamping plate 101 supports the inner ring of the bearing 17 and, together with the upper inner ring clamping plate 102, applies downward pressure to the inner ring of the bearing 17, fixing the inner ring of the bearing 17 relative to the lower inner ring clamping plate 101 and the upper inner ring clamping plate 102. Since the lower inner ring clamping plate 101 is rotatable, the inner ring and outer ring of the bearing 17 can rotate relative to each other. By moving the clamping seat 113 down once, the clamping and fixing of the inner and outer rings of the bearing can be completed, simplifying the clamping structure and making clamping more convenient.

[0026] like Figure 1 , Figure 2 , Figure 4 and Figure 6 As shown, further in this embodiment, the clamping drive assembly 11 includes a mounting frame 111, a clamping cylinder 112, a clamping seat 113, and a rotating shaft 114; the mounting frame 111 is fixed to the upper surface of the test bench 2; the clamping cylinder 112 is fixedly inserted through the upper surface of the mounting frame 111; the clamping seat 113 is fixed to the drive end of the clamping cylinder 112; the rotating shaft 114 is rotatably disposed at the bottom of the clamping seat 113, and the inner ring upper clamping plate 102 is detachably mounted at the bottom of the rotating shaft 114; the outer ring arc-shaped clamping block 104 is detachably mounted at the bottom of the clamping seat 113 and corresponds to the position of the annular stepped groove 105.

[0027] In actual testing, this embodiment uses the clamping cylinder 112 to drive the clamping seat 113 to move downwards. The clamping seat 113 can drive the outer ring arc-shaped clamping block 104 and the rotating shaft 114 to move downwards, while the rotating shaft 114 can drive the inner ring upper clamping plate 102 to move downwards. Since the outer ring arc-shaped clamping block 104 and the inner ring upper clamping plate 102 move downwards synchronously, the inner and outer rings of the bearing under test can be clamped and fixed synchronously under the action of a single driving source of the clamping cylinder 112, without affecting the relative rotation of the inner and outer rings of the bearing under test, which is convenient for clamping and testing.

[0028] like Figure 5 and Figure 6 As shown, further, in this embodiment, the positioning mechanism 12 includes multiple positioning blocks 121, multiple springs 122, and multiple extrusion wheels 123; the upper surface of the inner ring lower clamping plate 101 is provided with multiple annularly distributed sliding grooves 124, the positioning blocks 121 are slidably connected to the sliding grooves 124, and the side of the positioning blocks 121 near the axis of the inner ring lower clamping plate 101 is provided with an inclined extrusion ramp 125; the springs 122 are fixed between the side wall of the positioning blocks 121 and the groove wall of the sliding grooves 124; extrusion The wheel 123 is fixed to the bottom of the inner ring clamping plate 102, and the extrusion wheel 123 is set above the extrusion ramp 125. The extrusion wheel 123 pushes the positioning block 121 to abut against the inner ring side wall of the bearing 17 to be tested through the extrusion ramp 125. There are three positioning blocks 121, springs 122, extrusion wheels 123 and slide grooves 124. The side wall of the positioning block 121 that contacts the bearing 17 to be tested is arc-shaped, which improves the stability of the positioning block 121 in pressing against the inner ring of the bearing 17 to be tested.

[0029] In actual testing, when the inner ring upper clamping plate 102 moves downward, it can drive the extrusion roller 123 to move downward synchronously. The extrusion roller 123 is in pre-contact with the extrusion ramp 125 on the side wall of the positioning block 121. Under the action of the inclined surface of the extrusion ramp 125, the pressure of the extrusion roller 123 moving downward can be converted into a horizontal thrust on the positioning block 121. Since the positioning blocks 121 are evenly distributed in a ring on the surface of the inner ring lower clamping plate 101, when the bearing under test 17 is initially placed off-center, the positioning blocks 121 that are in pre-contact with the inner ring of the bearing under test 17 can... Move the bearing under test 17 until all three positioning blocks 121 are in contact with the inner sidewall of the inner ring of the bearing under test 17. At this time, the bearing under test 17 and the test shaft 3 remain coaxial, which can minimize the impact on test accuracy due to the offset of the bearing under test 17 during subsequent testing, and can reduce the accuracy requirements when initially placing the bearing under test 17. At the same time, since the positioning blocks 121 are in direct contact with the inner ring of the bearing under test 17, the radial off-center load pressure on the test shaft 3 can be transmitted to the bearing under test 17 more stably, which helps to improve the radial off-center load test effect.

[0030] like Figure 5 and Figure 6As shown, further, in this embodiment, the transmission assembly 13 includes a spline shaft 131 and a spline sleeve 132; the spline shaft 131 is fixed to the bottom of the inner ring upper clamping plate 102; the spline sleeve 132 is fixed to the upper surface of the inner ring lower clamping plate 101, and after the spline shaft 131 is inserted into the spline sleeve 132, the inner ring lower clamping plate 101 drives the inner ring upper clamping plate 102 to rotate through the spline sleeve 132 and the spline shaft 131.

[0031] In actual testing, in this embodiment, when the upper inner ring clamp 102 moves downward, the spline shaft 131 can be inserted into the spline sleeve 132, so that the upper inner ring clamp 102 and the lower inner ring clamp 101 can transmit rotational driving force through the spline shaft 131 and the spline sleeve 132. On the one hand, this can improve the clamping stability of the upper inner ring clamp 102 and the lower inner ring clamp 101 on the inner ring of the bearing 17 under test, making the rotation of the inner ring of the bearing 17 under test more stable. On the other hand, it can ensure stable transmission contact between the upper inner ring clamp 102 and the lower inner ring clamp 101 when the bearing 17 under test is not installed, which facilitates the inherent frictional resistance torque of the testing device itself and helps to reduce the frictional torque error in subsequent formal testing.

[0032] like Figure 3 and Figure 7 As shown, in this embodiment, a gear ring 14 is fixedly sleeved on the outer wall of the support sleeve 6; a rack 15 matching the gear ring 14 is provided on the inner side of the loading sleeve 7, and a horizontal drive assembly 16 for driving the rack 15 to move is installed on the loading sleeve 7.

[0033] In actual testing, in this embodiment, the core working performance of the damping bearing is constant damping holding force. That is, the core of the use of the damping bearing is not only the dynamic damping performance during rotation, but also the locking and anti-loosening ability in the static state. Its static friction torque directly determines the core performance of the component not slipping or shifting when stationary. Only by detecting the dynamic friction torque, the damping effect during the bearing rotation can be determined, but the maximum static friction performance after static contact cannot be detected. Therefore, the damping bearing must be tested for static friction torque. When testing the static friction torque, the inherent static friction resistance torque of the device itself is tested first when the bearing under test 17 is not installed. Then, after installing the bearing under test 17, the rack 15 drives the gear ring 14. The gear ring 14 applies a rotational force to the test shaft 3 through the support sleeve 6. By detecting the pushing force required for the rack 15 to drive the gear ring 14 and the radius of the gear ring 14, the static friction torque of the bearing under test 17 can be calculated. The calculation formula is: T=F1*r-F2*r, where T is the static friction torque, F1 is the pushing force of the rack 15 to push the gear ring 14 to start rotating from static, r is the pitch circle radius of the gear ring 14, and F2 is the pushing force of the rack 15 to push the gear ring 14 to start rotating from static when the bearing under test 17 is not installed. After the static friction torque test is completed, the dynamic friction torque test is performed. Thus, the static and dynamic friction torque tests of the bearing under test 17 can be completed in one clamping.

[0034] like Figure 3 and Figure 7 As shown, further, in this embodiment, the horizontal drive assembly 16 includes a horizontal cylinder 161, a second pressure sensor 162, and a connecting post 163; both side walls of the loading sleeve 7 are provided with grooves 164 corresponding to the positions of the rack 15, and the horizontal cylinder 161 is fixed inside one of the grooves 164; the second pressure sensor 162 is fixed to the drive end of the horizontal cylinder 161; the connecting post 163 is fixed to the detection end of the second pressure sensor 162, and the connecting post 163 is fixedly connected to the rack 15.

[0035] In actual testing, this embodiment uses a horizontal hydraulic cylinder 161 to push a second pressure sensor 162, which, in conjunction with a connecting column 163, can move a rack 15. The pushing force of the horizontal hydraulic cylinder 161 gradually increases. Under the action of static frictional resistance of the bearing 17 under test, the rack 15 cannot drive the gear ring 14 to rotate initially. However, as the pressure applied by the horizontal hydraulic cylinder 161 increases, the gear ring 14 begins to rotate. The second pressure sensor 162 can monitor the thrust applied by the horizontal hydraulic cylinder 161 to the rack 15 in real time, and thus measure the maximum thrust required for the rack 15 to drive the gear ring 14 to rotate, which is convenient for calculating the static friction torque.

[0036] The operation process of this invention is as follows: Before clamping the bearing 17 to be tested, the historical data of the equipment is cleared and zero-point calibration is completed. Then, the clamping cylinder 112 is controlled to drive the inner ring upper clamping plate 102 and the outer ring arc-shaped clamping block 104 to move down through the clamping seat 113 and the rotating shaft 114, so that the spline shaft 131 is inserted into the spline sleeve 132. The loading cylinder 91 is controlled to apply radial off-center load pressure to the support sleeve 6 through the first pressure sensor 92 and the loading wheel 8. Then, the test motor 4 is controlled to run stably at a preset low speed, driving the test shaft 3 and the dynamic torque sensor. The device 5, support sleeve 6, inner ring lower clamping plate 101, inner ring upper clamping plate 102, rotating shaft 114, etc. operate and run stably for 60 seconds. The inherent friction torque of the entire device when the bearing to be tested 17 is not installed is detected by the dynamic torque sensor 5. The inherent friction torque includes the transmission damping of the test motor 4, the transmission friction of the dynamic torque sensor 5, and the rotation friction of the rotating bearing of the rotating shaft 114. The average torque value of the test motor 4 from 10 seconds after starting to 10 seconds before stopping is taken as the reference value of the dynamic inherent friction torque. The bearing 17 to be tested is placed in the annular stepped groove 105 by manual operation or an external loading robot. Then, the clamping cylinder 112, through the clamping seat 113 and the rotating shaft 114, moves the inner ring upper clamping plate 102 and the outer ring arc-shaped clamping block 104 downwards. The inner ring upper clamping plate 102 drives the extrusion roller 123 to move downwards synchronously. When the extrusion roller 123 contacts the extrusion ramp 125 of the positioning block 121, under the extrusion action of the extrusion roller 123 on the extrusion ramp 125, the positioning block 121 moves horizontally along the slide groove 124 and finally abuts against the inner ring of the bearing 17 to be tested. Because the positioning blocks 121 are evenly distributed annularly on the surface of the inner ring lower clamping plate 101, ... Therefore, each positioning block 121 will push the bearing under test 17 to move in the annular stepped groove 105, so that the bearing under test 17 and the test shaft 3 remain coaxial. At this time, the inner ring of the bearing under test 17 is in contact with the inner ring lower clamping plate 101, and the outer ring is in contact with the outer ring support groove ring 103. When the clamping cylinder 112 finishes working, the inner ring lower clamping plate 101 and the inner ring upper clamping plate 102 clamp and fix the inner ring of the bearing under test 17, and the outer ring arc-shaped clamping block 104 and the outer ring support groove ring 103 clamp and fix the outer ring of the bearing under test 17. At the same time, the spline shaft 131 at the bottom of the inner ring upper clamping plate 102 is inserted into the spline sleeve 132 of the inner ring lower clamping plate 101. Subsequently, the loading cylinder 91 applies radial off-center load pressure to the support sleeve 6 through the first pressure sensor 92 and the loading wheel 8. The support sleeve 6 transmits the radial off-center load pressure to the bearing under test 17 through the test shaft 3, so that a non-uniform radial force is formed between the inner ring and the outer ring of the bearing under test 17. Next, the test motor 4 drives the test shaft 3 to rotate. The test shaft 3, through the clamping and fixing action of the inner ring lower clamp 101 and the inner ring upper clamp 102, can drive the inner ring of the bearing under test 17 to rotate. Since the outer ring of the bearing under test 17 is clamped and fixed by the outer ring arc-shaped clamp 104 and the outer ring support groove ring 103, the inner and outer rings of the bearing under test 17 rotate relative to each other. During the test, the dynamic torque sensor 5 collects the torque change signal of the test shaft 3 in real time and continuously, monitors the dynamic friction torque during the uniform speed operation stage, and performs error subtraction by combining the pre-calibrated dynamic inherent friction torque benchmark value, and finally obtains the true friction torque parameters of the bearing under test 17 under the off-center load condition, thus completing the bearing friction torque test.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A bearing friction torque testing fixture, comprising a base (1), a test platform (2), a test shaft (3), and a test motor (4); the test platform (2) is fixed on the top of the base (1), the test shaft (3) is rotatably mounted on the surface of the test platform (2), and the test motor (4) is fixed on the bottom of the test platform (2) and is connected to the test shaft (3) in a transmission connection, characterized in that, Also includes: Dynamic torque sensor (5), support sleeve (6), loading sleeve (7), loading wheel (8), loading assembly (9) and clamping unit (10); The dynamic torque sensor (5) is fixed on the upper end of the test bench (2), and the detection end of the dynamic torque sensor (5) is connected to the test shaft (3) in a transmission connection. The support sleeve (6) is fixedly sleeved to the shaft wall of the test shaft (3); the loading sleeve (7) is coaxially sleeved on the outside of the support sleeve (6) and fixedly connected to the test bench (2); the loading component (9) is installed on the side wall of the loading sleeve (7); the loading wheel (8) is installed on the detection end of the loading component (9), and the wheel wall of the loading wheel (8) is in contact with the outer side wall of the support sleeve (6); The clamping unit (10) is mounted on top of the test shaft (3) and is used to mount the bearing to be tested (17).

2. The bearing friction torque testing fixture according to claim 1, characterized in that, The loading assembly (9) includes a loading cylinder (91), a first pressure sensor (92), and a mounting plate (93); the loading cylinder (91) is fixedly inserted into the side wall of the loading sleeve (7); the first pressure sensor (92) is fixed to the movable end of the loading cylinder (91); the mounting plate (93) is fixed to the detection end of the first pressure sensor (92), and the loading wheel (8) is fixed to the side wall of the mounting plate (93).

3. The bearing friction torque testing fixture according to claim 1, characterized in that, The clamping unit (10) includes an inner ring lower clamping plate (101), an inner ring upper clamping plate (102), a clamping drive assembly (11), an outer ring support groove ring (103), an outer ring arc-shaped clamping block (104), a positioning mechanism (12), and a transmission assembly (13). The inner ring lower clamping plate (101) is detachably mounted on the top of the test shaft (3); the inner ring upper clamping plate (102) is coaxially disposed above the inner ring lower clamping plate (101), and the inner ring upper clamping plate (102) is mounted on the driving end of the clamping drive assembly (11), which is mounted on the upper surface of the test bench (2); the outer ring support groove ring (103) is sleeved on the outside of the inner ring lower clamping plate (101), and the outer ring support groove ring (103) The inner ring wall of the bearing is provided with an annular stepped groove (105); the outer ring arc-shaped clamping block (104) is installed on the driving end of the clamping drive assembly (11); the positioning mechanism (12) and the transmission assembly (13) are both arranged between the inner ring lower clamping plate (101) and the inner ring upper clamping plate (102). The positioning mechanism (12) is used to position the bearing to be tested (17). The inner ring lower clamping plate (101) is connected to the inner ring upper clamping plate (102) through the transmission assembly (13).

4. The bearing friction torque testing fixture according to claim 3, characterized in that, The clamping drive assembly (11) includes a mounting frame (111), a clamping cylinder (112), a clamping seat (113), and a rotating shaft (114); the mounting frame (111) is fixed on the upper surface of the test bench (2); the clamping cylinder (112) is fixedly inserted through the upper surface of the mounting frame (111); the clamping seat (113) is fixed at the driving end of the clamping cylinder (112); the rotating shaft (114) is rotatably disposed at the bottom of the clamping seat (113), and the inner ring upper clamping plate (102) is detachably installed at the bottom of the rotating shaft (114); the outer ring arc-shaped clamping block (104) is detachably installed at the bottom of the clamping seat (113) and corresponds to the position of the annular stepped groove (105).

5. The bearing friction torque testing fixture according to claim 3, characterized in that, The positioning mechanism (12) includes multiple positioning blocks (121), multiple springs (122), and multiple extrusion wheels (123); the upper surface of the inner ring lower clamping plate (101) is provided with multiple annularly distributed sliding grooves (124), the positioning blocks (121) are slidably connected to the sliding grooves (124), and the positioning blocks (121) are provided with inclined extrusion ramps (125) on the side of the positioning blocks (121) near the axis of the inner ring lower clamping plate (101); the springs (122) are fixed between the side wall of the positioning blocks (121) and the groove wall of the sliding grooves (124); the extrusion wheels (123) are fixed at the bottom of the inner ring upper clamping plate (102), and the extrusion wheels (123) are set above the extrusion ramps (125), and the extrusion wheels (123) push the positioning blocks (121) to abut against the inner ring side wall of the bearing to be tested (17) through the extrusion ramps (125).

6. The bearing friction torque testing fixture according to claim 3, characterized in that, The transmission assembly (13) includes a spline shaft (131) and a spline sleeve (132); the spline shaft (131) is fixed to the bottom of the inner ring upper clamping plate (102); the spline sleeve (132) is fixed to the upper surface of the inner ring lower clamping plate (101), and after the spline shaft (131) is inserted into the spline sleeve (132), the inner ring lower clamping plate (101) drives the inner ring upper clamping plate (102) to rotate through the spline sleeve (132) and the spline shaft (131).

7. The bearing friction torque testing fixture according to claim 1, characterized in that, The outer wall of the support sleeve (6) is fixedly fitted with a gear ring (14); the inner side of the loading sleeve (7) is provided with a rack (15) that matches the gear ring (14), and the loading sleeve (7) is equipped with a horizontal drive assembly (16) that drives the rack (15) to move.

8. The bearing friction torque testing fixture according to claim 7, characterized in that, The horizontal drive assembly (16) includes a horizontal cylinder (161), a second pressure sensor (162), and a connecting column (163); the two side walls of the loading sleeve (7) are provided with grooves (164) corresponding to the position of the rack (15), and the horizontal cylinder (161) is fixed inside one of the grooves (164); the second pressure sensor (162) is fixed at the drive end of the horizontal cylinder (161); the connecting column (163) is fixed at the detection end of the second pressure sensor (162), and the connecting column (163) is fixedly connected to the rack (15).

Images