Experimental measurement device and method for dragging resistance of bearing rolling body

Abstract

The invention relates to the technical field of bearing friction tests, in particular to an experimental measurement device and a measurement method for drag resistance of a rolling body of a rolling bearing. Comprising a wind tunnel experiment section, a pitot tube is arranged at the front end of the wind tunnel experiment section, the experiment piece is arranged on a measuring structure of the wind tunnel experiment section, a force sensor is arranged on the measuring structure, and the force sensor is connected with the wind tunnel experiment section. The force sensor is connected with a force acquisition computer through a force acquisition module, and the low-speed wind tunnel is further provided with a wind tunnel control computer. The device not only can measure the drag resistance of the bearing rolling body under different incoming flow velocity conditions, but also can meet the measurement requirements of rolling bodies with different sizes and different types; the device is simple to operate, and can measure the drag resistance borne by the bearing rolling body under different constraint space conditions at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of bearing friction testing, in particular to an experimental measuring device and a measuring method for the drag resistance of a rolling element of a rolling bearing. Background Art

[0002] When the main shaft bearing of an aircraft engine is working, moving dual surfaces will be formed between the components. In order to reduce the friction between the dual surfaces, reduce wear, and remove the hard inclusions formed, the main shaft bearing needs to be fully and effectively lubricated. At the same time, a large amount of heat is generated during the operation of the main shaft bearing, and the external high temperature environment will also transfer heat to the bearing. This requires the flow of lubricating oil to remove the heat to ensure that the bearing operates within a reasonable temperature range. In recent years, with the continuous increase in the main shaft speed of advanced aircraft engines, the working environment of the main shaft bearing has continued to deteriorate, which requires a more refined thermal analysis of the bearing to ensure the safety and reliability of the main shaft bearing.

[0003] During the operation of rolling bearings, only a very small amount of lubricating oil that enters the bearing will enter the contact area to form a lubricating oil film. Most of the lubricating oil will mix with air in the bearing ring cavity to form an oil-gas two-phase lubricating oil mist. When the bearing rotates, the rolling body will interact strongly with the oil-gas two-phase flow, resulting in significant fluid viscous friction loss. The force exerted on the bearing parts when they translate in the lubricating oil is called drag resistance, and the torque exerted on the bearing parts when they rotate in the lubricating oil is called eddy torque. Fluid viscosity loss constitutes a considerable part of the total power loss of the rolling element. When the bearing rotates at high speed, the fluid viscous friction loss can even reach about 50% of the total power loss of the bearing. Therefore, accurately calculating the drag resistance of the bearing rolling element moving in the bearing can more accurately analyze the bearing fluid viscous friction and improve the accuracy of the bearing heat generation calculation. However, the complex internal geometry and working environment of the bearing have brought great difficulties to the actual measurement of the drag resistance.

[0004] In the prior art, the research on the drag resistance of rolling elements in bearings is mainly focused on the numerical simulation part. There is a lack of experimental measurement devices and methods for the drag resistance of rolling elements in rolling bearings, which cannot meet the relevant experimental verification capabilities of existing and future aircraft engine main shaft bearings, as well as the research and development and design requirements of bearings. Summary of the invention

[0005] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a bearing rolling element drag resistance experimental measurement device and method, which can measure the bearing rolling element drag resistance in a constrained space, which is of great significance to the study of bearing friction and can solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: the bearing rolling element drag resistance experimental measurement device is characterized in that it includes a low-speed wind tunnel that provides air with a suitable wind speed for the experimental piece, the low-speed wind tunnel is fixed on the wind tunnel support, the low-speed wind tunnel includes a wind tunnel experimental section, a Pitot tube is arranged at the front end of the wind tunnel experimental section, the experimental piece is arranged on the measurement structure of the wind tunnel experimental section, a force sensor is arranged on the measurement structure, the force sensor is connected to the force acquisition computer through a force acquisition module, and the low-speed wind tunnel is also provided with a wind tunnel control computer.

[0007] The low-speed wind tunnel is also provided with an atmospheric pressure sensor, a temperature and humidity sensor. The wind tunnel control computer reads the temperature and humidity in the wind tunnel, the indoor atmospheric pressure and the indication of the differential pressure variable through the sensor, and then calculates the standard wind speed in the wind tunnel. According to the comparison result between the current wind speed and the wind tunnel wind speed set by the input in the computer, a corresponding instruction is issued to the frequency converter, and the rotation speed of the wind tunnel fan is changed by controlling the motor speed through the frequency converter, so as to achieve the control of the wind speed in the wind tunnel; by controlling the wind speed in the wind tunnel, the flow velocity of the rolling body in the experimental piece is controlled to simulate the revolution motion of the rolling body in the bearing at different speeds. The force sensor is used to measure the drag resistance of the bearing rolling body in the experimental piece. The force acquisition module is connected to the force acquisition computer, and the force acquisition module converts the pressure signal received by the sensor into a digital signal and transmits it to the force acquisition computer for recording.

[0008] The wind speed control range of the low-speed wind tunnel is 0m / s to 25m / s. The wind tunnel test section is 1.2m long and has a cross-section of a square of 0.3m×0.3m. Wind tunnel observation windows for observation are arranged on the left and right side walls of the wind tunnel test section, and the wind tunnel observation windows are acrylic window panels.

[0009] The measuring structure includes a vertical support installed on the transverse support, a swing shaft is installed on the vertical support through a swing shaft mounting hole, a swing rod is installed on the swing shaft, a cross bar is arranged at the upper end of the swing rod, and the lower end of the swing rod is connected to the support rod of the rolling body to be measured on the wind tunnel wall. A sensor bracket is also arranged on the vertical support, the sensor bracket is installed on the sensor bracket, and the force sensor is fixed on the sensor bracket.

[0010] The transverse support is installed on both sides of the wind tunnel test section to support the measurement structure. The vertical support is fixed to the transverse support by bolts. A plurality of bolt holes are reserved on the transverse support to meet the fixation of the vertical supports at different positions and to measure the drag resistance of rolling bodies at different positions. The swing shaft mounting hole is arranged on the upper part of the vertical support to support the swing shaft of the force amplification structure. The swing shaft serves as the fulcrum of the lever structure. The swing shaft is installed in the circular hole on the swing rod. The swing rod swings around the swing shaft. The lower end of the swing rod is fastened with the support rod of the measured rolling body by bolts. Due to the different force arm lengths of the swing rod, the drag resistance of the measured rolling body on the support rod of the measured rolling body is amplified. The sensor bracket is installed on the vertical support by bolts. The sensor bracket is installed on the sensor bracket by bolts. The force sensor is fixed to the sensor bracket by bolts. After the sensor is installed, the sensor height is consistent with the crossbar height.

[0011] The experimental piece comprises a rolling body support seat, on which a plurality of rolling bodies to be tested are arranged through a retaining frame and a rolling body support rod to be tested, and an acrylic plate is installed on the rolling body support seat through an acrylic plate support module.

[0012] The acrylic plate support module is fixed to the rolling body support seat by bolts, and the acrylic plate is fixed to the acrylic plate support module by bolts. The acrylic plate provides a flat interlayer constraint space for the rolling body to be tested. The acrylic plate support module is replaced according to the experimental requirements to adjust the size of the interlayer space; experimental piece installation positioning holes are reserved on the acrylic plate support module and the rolling body support seat. The hole positions of the experimental piece installation positioning holes are the same as the hole positions of the side walls of the wind tunnel test section, which are used to install and fix the experimental piece in the wind tunnel test section; a plurality of rolling body installation holes are reserved on the rolling body support seat for fixing the positions of the rolling body to be tested and the rolling bodies arranged in parallel, and different rolling body installation holes are used to realize The invention relates to the measurement of drag resistance under conditions of different numbers of rolling elements and spacing between rolling elements; support rods of the rolling elements to be measured are installed on both sides of the rolling elements to be measured, and the support rods of the rolling elements to be measured pass through the rolling element mounting holes on the rolling element support seats and are connected to the measuring structure, so that the rolling elements to be measured are suspended in the air without contacting other structures; support rods of the rolling elements to be arranged in parallel are installed on both sides of the rolling elements to make the rolling elements to be arranged in parallel be installed in the rolling element mounting holes, so as to provide a flow environment for the rolling elements to be measured; the retaining frame is placed on the support rods of the rolling elements to be arranged in parallel, and the retaining frame fixing module fixes the retaining frame by bolts; the experimental piece can provide a flow environment for the rolling elements to be measured that simulates the actual situation in the bearing.

[0013] The interval between two adjacent holes of the multiple rolling body mounting holes is 130mm, the diameter of the rolling body mounting hole is 10mm, the diameter of the experimental piece mounting positioning hole is 5mm, the diameter of the tested rolling body support rod is 5mm, and the diameter of the parallel arranged rolling body support rod is 10mm.

[0014] The method for measuring the drag resistance of a rolling element of a bearing is characterized by comprising the following steps: (1) Check the low-speed wind tunnel, pitot tube and wind tunnel control computer to ensure the safe operation of the wind tunnel and accurate wind speed measurement; (2) Open the wind tunnel observation window on one side of the wind tunnel test section, fix the test piece to the wind tunnel wall with bolts, close the wind tunnel observation window, connect the tested rolling element support rods on both sides of the tested rolling element with the two swing rods in the measurement structure with bolts, so that the tested rolling element is suspended in the air, install the force sensor and connect it to the force acquisition computer, and ensure that the other end of the force amplification structure contacts the force sensor; (3) Check whether there are other foreign objects in the low-speed wind tunnel, verify whether the test piece is installed properly, whether the tested rolling element support rod is suspended, and whether the other end of the force amplification structure contacts the pressure sensor; (4) Open the force acquisition computer software, turn on the data recording function, and prepare to collect force; (5) Start the low-speed wind tunnel and control the wind speed by controlling the frequency. After the wind speed changes steadily, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer; (6) Change the fan operating frequency in sequence and measure the value of the force sensor at different incoming wind speeds; (7) After the data collection is completed, the wind speed of the wind tunnel is gradually reduced. After the wind tunnel stops running, the wind tunnel is closed and the force sensor data collection software is closed. Thus, the measurement experiment of the drag resistance of the rolling element of a bearing of a certain structural form is completed; (8) Remove the experimental piece, change the structure of the experimental piece as required, repeat steps 2 to 8, and conduct the experiment of the next structural form; (9) The drag resistance data collected by the force sensor is exported and processed.

[0015] The experimental data processing process in the ninth step includes the following steps: 1) For the measurement results at any wind speed, after the sensor readings are stable, select the average value of the measurement data over a period of time as the measurement result of the drag resistance of the rolling element at that wind speed; 2) Analyze the experimental measurement results, identify unreasonable data and eliminate them; 3) For multiple groups of experiments conducted under the same conditions, the average value of the multiple groups of experiments is taken as the measurement result of the drag resistance of the rolling element under the wind speed.

[0016] The beneficial effects of the present invention are as follows: the present invention provides a bearing rolling element drag resistance experimental measurement device and method, which can provide a flow environment in a constrained space for the rolling element to be measured, and can not only measure the drag resistance of the bearing rolling element under different incoming flow velocities on the experimental bench, but also meet the measurement requirements of rolling elements of different sizes and types; the device is simple to operate, and can measure the drag resistance experienced by the bearing rolling element under different incoming flow velocities, and can also measure the drag resistance experienced by bearing rolling elements of different sizes and types; at the same time, it can measure the drag resistance experienced by the bearing rolling element under different constrained space conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a bearing rolling element drag resistance experimental measurement device of the present invention; Figure 2 The experimental parts in the embodiment of the present invention are shown in FIG. Figure 1 ; Figure 3 The experimental parts in the embodiment of the present invention are shown in FIG. Figure 2 ; Figure 4 is a schematic diagram of a measurement structure in an embodiment of the present invention; Figure 5 It is a schematic diagram of the process provided by the present invention.

[0018] In the figure, 1. low-speed wind tunnel, 2. pitot tube, 3. wind tunnel control computer, 4. wind tunnel support, 5. force sensor, 6. force acquisition module, 7. force acquisition computer, 8. wind tunnel test section, 9. test piece, 10. measurement structure, 11. acrylic plate, 12. acrylic plate support module, 13. rolling body support seat, 14. rolling body mounting hole, 15. test piece mounting positioning hole, 16. measured rolling body, 17. measured rolling body support rod, 18. rolling body arranged in parallel, 19. cage, 20. cage fixing module, 21. rolling body support rod arranged in parallel, 22. vertical support, 23. swing shaft mounting hole, 24. swing shaft, 25. swing rod, 26. cross bar, 27. sensor support, 28. sensor bracket, 29. wind tunnel wall, 30. wind tunnel observation window, 31. transverse support, 32. bolt hole. DETAILED DESCRIPTION

[0019] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0020] In order to achieve the above object, the present invention provides the following specific implementation methods: Figure 1As shown, the bearing rolling element drag resistance experimental measurement device is characterized in that it includes a low-speed wind tunnel 1 for providing air with a suitable wind speed for the experimental piece 9, the low-speed wind tunnel 1 is fixed on a wind tunnel support 4, the low-speed wind tunnel 1 includes a wind tunnel experimental section 8, a Pitot tube 2 is arranged at the front end of the wind tunnel experimental section 8, the experimental piece 9 is arranged on a measuring structure 10 of the wind tunnel experimental section 8, a force sensor 5 is arranged on the measuring structure 10, and the force sensor 5 is connected to a force acquisition computer 7 through a force acquisition module 6, and a wind tunnel control computer 3 is also arranged on the low-speed wind tunnel 1.

[0021] The low-speed wind tunnel 1 is also provided with an atmospheric pressure sensor, a temperature and humidity sensor. The wind tunnel control computer 3 reads the temperature and humidity in the wind tunnel, the indoor atmospheric pressure and the indication of the differential pressure variable through the sensor, and then calculates the standard wind speed in the wind tunnel. According to the comparison result between the current wind speed and the wind tunnel wind speed input and set in the computer, a corresponding instruction is issued to the frequency converter, and the rotation speed of the wind tunnel fan is changed by controlling the motor speed through the frequency converter, so as to achieve the control of the wind speed in the wind tunnel; by controlling the wind speed in the wind tunnel, the flow velocity of the rolling body in the experimental piece 9 is controlled to simulate the revolution motion of the rolling body in the bearing at different speeds. The force sensor 5 is used to measure the drag resistance of the bearing rolling body in the experimental piece. The force acquisition module 6 is connected to the force acquisition computer 7. The force acquisition module 6 converts the pressure signal received by the sensor into a digital signal and transmits it to the force acquisition computer 7 for recording.

[0022] like Figure 4 As shown, the wind speed control range of the low-speed wind tunnel 1 is 0m / s to 25m / s, the wind tunnel test section 8 is 1.2m long and has a cross-section of a square of 0.3m×0.3m. Wind tunnel observation windows 30 for observation are arranged on the left and right side walls of the wind tunnel test section 8, and the wind tunnel observation windows 30 are acrylic window panels.

[0023] like Figure 2 , 3 As shown in Figure 4, the measuring structure 10 includes a vertical support 22 installed on a horizontal support 31, a swing shaft 24 is installed on the vertical support 22 through a swing shaft mounting hole 23, a swing rod 25 is installed on the swing shaft 24, a cross bar 26 is provided on the upper end of the swing rod 25, and the lower end of the swing rod 25 is connected to the measured rolling body support rod 17 on the wind tunnel wall 29. A sensor bracket 28 is also provided on the vertical support 22, the sensor bracket 27 is installed on the sensor bracket 28, and the force sensor 5 is fixed on the sensor bracket 27.

[0024] The lateral support 31 is installed on both sides of the wind tunnel test section 8 to support the measurement structure 10. The vertical support 22 is fixed to the lateral support 31 by bolts. A plurality of bolt holes 32 are reserved on the lateral support 31 to meet the needs of fixing the vertical support 22 at different positions and to measure the drag resistance of the rolling body at different positions. The swing shaft mounting hole 23 is arranged on the upper part of the vertical support 22 to support the swing shaft 24 of the installation force amplification structure. The swing shaft 24 serves as the fulcrum of the lever structure. The swing shaft 24 is installed in the circular hole on the swing rod 25. The swing rod 25 swings around the swing shaft 24. The lower end of the rod 25 is fastened to the measured rolling body support rod 17 by bolts. Due to the different force arm lengths of the swing rod 25, the drag resistance of the measured rolling body 16 on the measured rolling body support rod 17 is amplified. The sensor bracket 28 is installed on the vertical support 22 by bolts, the sensor support 27 is installed on the sensor bracket 28 by bolts, and the force sensor 5 is fixed to the sensor support 27 by bolts. After the sensor is installed, the sensor height is consistent with the height of the cross bar 26; the measuring structure 10 can amplify the drag resistance of the measured rolling body 16, which is convenient for measurement and reduces experimental errors.

[0025] The experimental piece 9 comprises a rolling body support seat 13 , on which a plurality of rolling bodies 16 to be tested are arranged via a retaining frame 19 and a rolling body support rod 17 to be tested, and an acrylic plate 11 is mounted on the rolling body support seat 13 via an acrylic plate support module 12 .

[0026] The acrylic plate support module 12 is fixed to the rolling body support seat 13 by bolts, and the acrylic plate 11 is fixed to the acrylic plate support module 12 by bolts. The acrylic plate 11 provides a flat interlayer constraint space for the tested rolling body 16. The acrylic plate support module 12 is replaced according to the experimental requirements to adjust the size of the interlayer space; the acrylic plate support module 12 and the rolling body support seat 13 are both reserved with experimental piece installation positioning holes 15, and the hole positions of the experimental piece installation positioning holes 15 are the same as the hole positions of the side walls of the wind tunnel test section 8, which are used to install and fix the experimental piece in the wind tunnel test section 8; the rolling body support seat 13 is reserved with a plurality of rolling body installation holes 14 for fixing the positions of the tested rolling body 16 and the parallel arranged rolling bodies 18, and by using different rolling body installation holes 14 to realize The drag resistance is measured under conditions of different numbers of rolling elements and rolling element spacing; the measured rolling element support rods 17 are installed on both sides of the measured rolling element 16, and the measured rolling element support rods 17 pass through the rolling element mounting holes 14 on the rolling element support seat 13 and are connected to the measuring structure 10, so that the measured rolling element 16 is suspended in the air without contacting other structures; the parallel arranged rolling elements 18 are installed on both sides of the parallel arranged rolling elements 18, so that the parallel arranged rolling elements 18 are installed in the rolling element mounting holes 14, providing a flow environment for the measured rolling elements 16; the retaining frame 19 is placed on the parallel arranged rolling element support rods 21, and the retaining frame fixing module 20 fixes the retaining frame 19 by bolts; the experimental piece 9 can provide a flow environment for the measured rolling element 16 that simulates the actual situation in the bearing.

[0027] The interval between two adjacent holes of the multiple rolling body mounting holes 14 is 130mm, the diameter of the rolling body mounting hole 14 is 10mm, the diameter of the experimental piece mounting positioning hole 15 is 5mm, the diameter of the tested rolling body support rod 17 is 5mm, and the diameter of the parallel arranged rolling body support rod 21 is 10mm.

[0028] like Figure 5 As shown, the experimental measurement method for the drag resistance of a bearing rolling element is characterized by comprising the following steps: (1) Check the low-speed wind tunnel 1, the Pitot tube 2 and the wind tunnel control computer 3 to ensure the safe operation of the wind tunnel and accurate wind speed measurement; (2) Open the wind tunnel observation window 30 on one side of the wind tunnel test section 8, fix the test piece 9 to the wind tunnel wall 29 as a whole by bolts, close the wind tunnel observation window 30, connect the tested rolling element support rods 17 on both sides of the tested rolling element 16 to the two swing rods 25 in the measuring structure 10 by bolts, so that the tested rolling element 16 is suspended in the air, install the force sensor 5 and connect it to the force acquisition computer 7, and ensure that the other end of the force amplification structure contacts the force sensor 5; (3) Check whether there are other foreign objects in the low-speed wind tunnel 1, verify whether the test piece 9 is installed properly, whether the tested rolling element support rod 17 of the tested rolling element 16 is suspended, and whether the other end of the force amplification structure contacts the pressure sensor 5; (4) Open the force acquisition computer software, turn on the data recording function, and prepare to collect force; (5) Start the low-speed wind tunnel 1, control the wind speed by controlling the frequency, and after the wind speed changes stably, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer 3; (6) Change the fan operating frequency in sequence and measure the value of force sensor 5 at different incoming wind speeds; (7) After the data collection is completed, the wind speed of the wind tunnel is gradually reduced. After the wind tunnel stops running, the wind tunnel is closed and the force sensor data collection software is closed. Thus, the measurement experiment of the drag resistance of the rolling element of a bearing of a certain structural form is completed; (8) Remove the experimental piece 9, replace the structure of the experimental piece as required, repeat steps 2 to 8, and conduct the experiment of the next structural form; (9) The drag resistance data collected by the force sensor 5 is exported and processed.

[0029] The experimental data processing process in the ninth step includes the following steps: 1) For the measurement results at any wind speed, after the sensor readings are stable, select the average value of the measurement data over a period of time as the measurement result of the drag resistance of the rolling element at that wind speed; 2) Analyze the experimental measurement results, identify unreasonable data and eliminate them; 3) For multiple groups of experiments conducted under the same conditions, the average value of the multiple groups of experiments is taken as the measurement result of the drag resistance of the rolling element under the wind speed.

[0030] A bearing rolling element drag resistance experimental measurement device and method. During the test, during the operation of the bearing, the rolling element is always in a tangent state with the inner and outer raceways. Therefore, in the design of the experimental device, the curvature of the inner and outer rings of the bearing is ignored, and the annular cavity space is changed into a straight interlayer space. In addition, during the operation of the bearing, the drag resistance of the rolling element will also be affected by the adjacent rolling elements in front and behind. The experimental device is equipped with rolling elements of the same size arranged in parallel in front and behind the rolling element to be tested. Together with the upper and lower acrylic plates, they create flow conditions in the bearing for the rolling element to be tested. In the wind tunnel simulation experiment, single-phase fluid flow is used to simulate the oil-gas two-phase flow in the bearing. In addition, due to the actual wind speed and flow conditions in the wind tunnel, the resistance of a single rolling element is very small. In order to reduce the error and facilitate measurement, a new measurement scheme is established in the device, which uses a force amplification measurement structure based on the lever principle to amplify the drag resistance of the rolling element to be tested. One end of the force amplification structure is connected to the rolling element to be tested by bolts, and the rolling element to be tested is suspended in the wind tunnel through the support of the support. The other end is connected to the crossbar, and the crossbar contacts the force sensor. The length ratio of the two force arms of the force amplification structure is 5:1, which can amplify the drag resistance of the rolling element under test by 5 times.

[0031] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bearing rolling element drag resistance experimental measurement device, characterized in that: The invention comprises a low-speed wind tunnel (1) for providing air with a suitable wind speed for an experimental piece (9). The low-speed wind tunnel (1) is fixed on a wind tunnel support (4). The low-speed wind tunnel (1) comprises a wind tunnel experimental section (8). A Pitot tube (2) is arranged at the front end of the wind tunnel experimental section (8). The experimental piece (9) is arranged on a measuring structure (10) of the wind tunnel experimental section (8). A force sensor (5) is arranged on the measuring structure (10). The force sensor (5) is connected to a force acquisition computer (7) via a force acquisition module (6). The low-speed wind tunnel (1) is also provided with a wind tunnel control computer (3).

2. A bearing rolling element drag resistance test measurement device as claimed in claim 1, characterized in that: The low-speed wind tunnel (1) is also provided with an atmospheric pressure sensor, a temperature and humidity sensor, and the wind tunnel control computer (3) reads the temperature and humidity in the wind tunnel, the indoor atmospheric pressure and the indication of the differential pressure transducer through the sensors, and then calculates the standard wind speed in the wind tunnel. According to the comparison result between the current wind speed and the wind tunnel wind speed input and set in the computer, a corresponding instruction is issued to the frequency converter, and the rotation speed of the wind tunnel fan is changed by controlling the motor speed through the frequency converter, so as to achieve the control of the wind speed in the wind tunnel; by controlling the wind speed in the wind tunnel, the flow velocity of the rolling body in the experimental piece (9) is controlled to simulate the revolution motion of the rolling body in the bearing at different speeds. The force sensor (5) is used to measure the drag resistance of the bearing rolling body in the experimental piece. The force acquisition module (6) is connected to the force acquisition computer (7), and the force acquisition module (6) converts the pressure signal received by the sensor into a digital signal and transmits it to the force acquisition computer (7) for recording.

3. A bearing rolling element drag resistance test measurement device as claimed in claim 1 or 2, characterized in that: The wind speed control range of the low-speed wind tunnel (1) is 0 m / s to 25 m / s. The wind tunnel test section (8) is 1.2 m in length and has a cross-section of a square of 0.3 m×0.3 m. Wind tunnel observation windows (30) for observation are arranged on the left and right side walls of the wind tunnel test section (8). The wind tunnel observation windows (30) are acrylic window panels.

4. A bearing rolling element drag resistance test measurement device as claimed in claim 1, characterized in that: The measuring structure (10) comprises a vertical support (22) mounted on a transverse support (31); a swing shaft (24) is mounted on the vertical support (22) through a swing shaft mounting hole (23); a swing rod (25) is mounted on the swing shaft (24); a cross bar (26) is arranged at the upper end of the swing rod (25); the lower end of the swing rod (25) is connected to a measured rolling body support rod (17) on a wind tunnel wall (29); a sensor bracket (28) is also arranged on the vertical support (22); the sensor bracket (27) is mounted on the sensor bracket (28); and the force sensor (5) is fixed on the sensor bracket (27).

5. The bearing rolling element drag resistance test measurement device according to claim 1, characterized in that: The experimental piece (9) comprises a rolling body support seat (13), on which a plurality of rolling bodies (16) to be tested are arranged via a retaining frame (19) and a rolling body support rod (17), and an acrylic plate (11) is mounted on the rolling body support seat (13) via an acrylic plate support module (12).

6. A bearing rolling element drag resistance test measurement device as claimed in claim 4, characterized in that: The transverse support (31) is installed on both sides of the wind tunnel test section (8) to support the measurement structure (10). The vertical support (22) is fixed to the transverse support (31) by bolts. A plurality of bolt holes (32) are reserved on the transverse support (31) to meet the needs of fixing the vertical supports (22) at different positions and to measure the drag resistance of rolling bodies at different positions. The swing shaft installation hole (23) is arranged on the upper part of the vertical support (22) to support the swing shaft (24) of the installation force amplification structure. The swing shaft (24) serves as the fulcrum of the lever structure. The swing shaft (24) is installed on the round swing rod (25). In the hole, the swing rod (25) swings around the swing axis (24), and the lower end of the swing rod (25) is locked with the measured rolling body support rod (17) by bolts. Due to the different force arm lengths of the swing rod (25), the drag resistance of the measured rolling body (16) on the measured rolling body support rod (17) is amplified. The sensor bracket (28) is installed on the vertical support (22) by bolts, and the sensor bracket (27) is installed on the sensor bracket (28) by bolts. The force sensor (5) is fixed on the sensor bracket (27) by bolts. After the sensor is installed, the height of the sensor is consistent with the height of the cross bar (26).

7. A bearing rolling element drag resistance test measurement device as claimed in claim 5, characterized in that: The acrylic plate support module (12) is fixed to the rolling body support seat (13) by bolts, and the acrylic plate (11) is fixed to the acrylic plate support module (12) by bolts. The acrylic plate (11) provides a flat interlayer constraint space for the rolling body (16) to be tested. The acrylic plate support module (12) is replaced according to the experimental requirements to adjust the size of the interlayer space. The acrylic plate support module (12) and the rolling body support seat (13) are both reserved with experimental piece installation positioning holes (15). The hole positions of the experimental piece installation positioning holes (15) are the same as the hole positions of the side walls of the wind tunnel test section (8) and are used to install and fix the experimental piece in the wind tunnel test section (8). The rolling body support seat (13) is reserved with a plurality of rolling body installation holes (14) for fixing the positions of the rolling body (16) to be tested and the rolling bodies (18) arranged in parallel. By using different rolling body installation holes (14), the experimental piece installation positioning holes (15) are used to fix the positions of the rolling body (16) to be tested and the rolling bodies (18) arranged in parallel are fixed. The invention relates to a method for measuring drag resistance under conditions of different rolling element numbers and rolling element spacings; a rolling element support rod (17) to be measured is installed on both sides of a rolling element (16) to be measured, and the rolling element support rod (17) to be measured passes through a rolling element mounting hole (14) on a rolling element support seat (13) and is connected to a measuring structure (10), so that the rolling element (16) to be measured is suspended in the air and does not contact other structures; rolling element support rods (21) to be arranged in parallel are installed on both sides of the rolling elements (18) to install the rolling elements (18) in parallel in the rolling element mounting hole (14), so that a flow environment is provided for the rolling elements (16) to be measured; a retaining frame (19) is placed on the rolling element support rods (21) to be arranged in parallel, and a retaining frame fixing module (20) fixes the retaining frame (19) by bolts; the experimental piece (9) can provide a flow environment simulating the actual situation in the bearing for the rolling element (16) to be measured.

8. A bearing rolling element drag resistance test measurement device as claimed in claim 7, characterized in that: The interval between two adjacent holes of the plurality of rolling element mounting holes (14) is 130 mm, the diameter of the rolling element mounting hole (14) is 10 mm, the diameter of the test piece mounting positioning hole (5) is 5 mm, the diameter of the tested rolling element support rod (17) is 5 mm, and the diameter of the parallel arranged rolling element support rods (21) is 10 mm.

9. A method for measuring the drag resistance of a bearing rolling element, characterized in that: The following steps are involved: The first step is to check the low-speed wind tunnel (1), the pitot tube (2) and the wind tunnel control computer (3) to ensure that the wind tunnel is operating safely and the wind speed measurement is accurate; The second step is to open the wind tunnel observation window (30) on one side of the wind tunnel test section (8), fix the test piece (9) to the wind tunnel wall (29) as a whole by bolts, close the wind tunnel observation window (30), connect the tested rolling body support rods (17) on both sides of the tested rolling body (16) to the two swing rods (25) in the measuring structure (10) by bolts, so that the tested rolling body (16) is suspended in the air, install the force sensor (5) and connect it to the force acquisition computer (7), and ensure that the other end of the force amplification structure contacts the force sensor (5); The third step is to check whether there are other foreign objects in the low-speed wind tunnel (1), verify whether the test piece (9) is installed intact, whether the tested rolling element support rod (17) of the tested rolling element (16) is suspended, and whether the other end of the force amplification structure contacts the pressure sensor (5); Step 4: Start the force acquisition computer software, turn on the data recording function, and prepare for force acquisition; Step 5: Start the low-speed wind tunnel (1), control the wind speed by controlling the frequency, and after the wind speed changes stably, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer (3); Step 6, changing the fan operating frequency in turn, and measuring the value of the force sensor (5) at different incoming wind speeds; Step 7: After the data collection is completed, the wind speed of the wind tunnel is gradually reduced. After the wind tunnel stops running, the wind tunnel is closed and the force sensor data collection software is closed. Thus, the measurement experiment of the drag resistance of the rolling element of a bearing of a certain structural form is completed. Step 8: Remove the experimental piece (9), replace the structure of the experimental piece as required, repeat steps 2 to 8, and conduct experiments on the next structural form; The ninth step is to export the drag resistance data collected by the force sensor (5) and perform data processing.

10. A bearing rolling element drag resistance experimental measurement method as claimed in claim 9, characterized in that: The experimental data processing process in the ninth step includes the following steps: (1) For the measurement results at any wind speed, after the sensor readings are stable, the average value of the measurement data over a period of time is selected as the measurement result of the drag resistance of the rolling element at that wind speed; (2) Analyze the experimental measurement results, identify unreasonable data and eliminate them; (3) For multiple groups of experiments carried out under the same conditions, the average value of the multiple groups of experiments is taken as the measurement result of the drag resistance of the rolling element under the wind speed.

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