A bearing rolling body drag force experimental measurement device and method

Abstract

The present application relates to the technical fields of bearing friction test, especially to a kind of experimental measuring device and measuring method of rolling bearing rolling body drag resistance. Including the low-speed wind tunnel of air suitable for providing wind speed for experimental piece, the low-speed wind tunnel is fixed on wind tunnel support, and the low-speed wind tunnel includes wind tunnel experimental section, and the front end of wind tunnel experimental section is provided with pitot tube, experimental piece is arranged on the measuring structure of wind tunnel experimental section, force sensor is arranged on the measuring structure, and force sensor is connected with force acquisition computer by force acquisition module, and wind tunnel control computer is further arranged on the low-speed wind tunnel. The present application can not only measure the drag resistance of bearing rolling body under different incoming flow velocity conditions, but also meet the measurement requirements of different sizes and different types of rolling bodies;Its device is simple to operate, and the drag resistance of bearing rolling body under different constraint space conditions can be measured simultaneously.

Description

Technical Field

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

[0002] When the main shaft bearings of aircraft engines are operating, moving dual surfaces are formed between the various components. To reduce friction between the dual surfaces, minimize wear, and remove any hard inclusions that form, the main shaft bearings require sufficient and effective lubrication. Furthermore, the main shaft bearings generate a large amount of heat during operation, and the high external temperature environment also transfers heat to the bearings. This heat needs to be removed through the flow of lubricating oil to ensure that the bearings operate within a reasonable temperature range. In recent years, with the continuous increase in the main shaft speed of advanced aircraft engines, the operating environment of the main shaft bearings has continued to deteriorate, requiring more refined thermal analysis of the bearings to ensure the safety and reliability of the main shaft bearings.

[0003] During the operation of rolling bearings, only a very small amount of the lubricating oil that enters the bearing enters the contact area to form a lubricating film. The majority of the lubricating oil mixes with air in the bearing ring cavity to form an oil-gas two-phase lubricating mist. As the bearing rotates, the rolling elements interact strongly with the oil-gas two-phase flow, resulting in significant fluid viscous friction losses. The force exerted on bearing parts as they translate in the lubricating oil is called drag resistance, and the torque exerted on bearing parts as they rotate in the lubricating oil is called eddy torque. Fluid viscous losses constitute a significant portion of the total power loss of the rolling elements. At high-speed bearing rotation, fluid viscous friction losses can even reach approximately 50% of the total bearing power loss. Therefore, accurately calculating the drag resistance of the rolling elements moving within the bearing can more accurately analyze the bearing fluid viscous friction and improve the accuracy of bearing heat generation calculations. However, the complex internal geometry and operating environment of the bearing make the actual measurement of drag resistance extremely difficult.

[0004] In the existing technology, the research on the drag resistance of rolling elements in bearings mainly focuses 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 existing technology 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 solves the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: the above-mentioned 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 provided at the front end of the wind tunnel experimental section, the experimental piece is set on the measurement structure of the wind tunnel experimental section, a force sensor is provided 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 differential pressure transducer reading 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 motor speed is controlled by the frequency converter to change the rotation speed of the wind tunnel fan, thereby achieving 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 element in the experimental piece is controlled to simulate the revolution motion of the rolling element in the bearing at different speeds. The force sensor is used to measure the drag resistance of the bearing rolling element in the experimental piece. The force acquisition module is connected to the force acquisition computer. 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 0.3m×0.3m square. Wind tunnel observation windows for observation are provided on the left and right side walls of the wind tunnel test section. The wind tunnel observation windows are acrylic window panels.

[0009] The measuring structure includes a vertical support installed on the horizontal support, a swing shaft is installed on the vertical support through the swing shaft mounting hole, a swing rod is installed on the swing shaft, a cross bar is provided at the upper end of the swing rod, and the lower end of the swing rod is connected to the support rod of the measured rolling body on the wind tunnel wall. A sensor bracket is also provided 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 horizontal support is installed on both sides of the wind tunnel test section to support the measurement structure. The vertical support is fixed to the horizontal support by bolts. Multiple groups of bolt holes are reserved on the horizontal support to meet the fixation of vertical supports at different positions and to measure the drag resistance of rolling bodies at different positions. The swing shaft mounting hole is set 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 to 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 includes a rolling body support seat, on which a plurality of rolling bodies to be tested are arranged through a retaining frame and a supporting rod of the rolling body to be tested, and an acrylic plate is installed on the rolling body support seat through an acrylic plate supporting module.

[0012] The acrylic plate support module is fixed to the rolling element 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 element to be tested. The acrylic plate support module is replaced according to the experimental requirements to adjust the size of the interlayer space; the acrylic plate support module and the rolling element support seat are both reserved with experimental piece installation positioning holes, and 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; the rolling element support seat is reserved with multiple rolling element installation holes for fixing the positions of the rolling element to be tested and the rolling elements arranged in parallel, and by using different rolling element installation holes to realize The invention relates to a method for measuring drag resistance under conditions of different numbers of rolling elements and spacing between rolling elements; support rods for the rolling elements to be measured are installed on both sides of the rolling elements to be measured, and the support rods for 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 for the rolling elements to be arranged in parallel are installed on both sides of the rolling elements to be arranged in parallel, so that the rolling elements to be arranged in parallel are mounted in the rolling element mounting holes, providing a flow environment for the rolling elements to be measured; the cage is placed on the support rods for the rolling elements to be arranged in parallel, and the cage fixing module fixes the cage 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 element mounting holes is 130 mm, the diameter of the rolling element mounting hole is 10 mm, the diameter of the experimental piece mounting positioning hole is 5 mm, the diameter of the tested rolling element support rod is 5 mm, and the diameter of the parallel arranged rolling element support rod is 10 mm.

[0014] The method for measuring the drag resistance of a bearing rolling element is characterized by comprising the following steps:

[0015] (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;

[0016] (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 rolling element support rods on both sides of the rolling element to the two swing rods in the measurement structure with bolts, so that the 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;

[0017] (3) Check whether there are any foreign objects in the low-speed wind tunnel, verify whether the test piece is installed properly, whether the support rod of the tested rolling element is suspended in the air, and whether the other end of the force amplification structure contacts the pressure sensor;

[0018] (4) Open the force acquisition computer software, turn on the data recording function, and prepare to collect force;

[0019] (5) Start the low-speed wind tunnel and control the wind speed by controlling the frequency. After the wind speed changes stabilize, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer;

[0020] (6) Change the fan operating frequency in sequence and measure the value of the force sensor at different incoming wind speeds;

[0021] (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 acquisition software is closed. This completes the measurement experiment of the drag resistance of the bearing rolling element of one structural form;

[0022] (8) Remove the experimental piece, change the structure of the experimental piece according to the requirements, repeat steps 2 to 8, and conduct the experiment of the next structural form;

[0023] (9) The drag resistance data collected by the force sensor is exported and processed.

[0024] The experimental data processing process in the ninth step includes the following steps:

[0025] 1) For the measurement results at any wind speed, after the sensor reading stabilizes, 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;

[0026] 2) Analyze the experimental measurement results, identify unreasonable data and eliminate them;

[0027] 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 at the wind speed.

[0028] 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

[0029] Figure 1 It is a structural schematic diagram of the bearing rolling element drag resistance experimental measurement device of the present invention;

[0030] Figure 2 This is a schematic diagram of the experimental piece in the embodiment of the present invention Figure 1 ;

[0031] Figure 3 This is a schematic diagram of the experimental piece in the embodiment of the present invention Figure 2 ;

[0032] Figure 4 is a schematic diagram of a measurement structure in an embodiment of the present invention;

[0033] Figure 5 It is a schematic flow chart of the method provided by the present invention.

[0034] 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 element support seat, 14. rolling element mounting hole, 15. test piece mounting positioning hole, 16. measured rolling element, 17. measured rolling element support rod, 18. rolling elements arranged in parallel, 19. cage, 20. cage fixing module, 21. rolling element 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

[0035] The principles and features of the present invention are described below with reference to 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.

[0036] In order to achieve the above object, the present invention provides the following specific implementation methods: Figure 1 As shown, the bearing rolling element drag resistance experimental measurement device is characterized by including a low-speed wind tunnel 1 that provides 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 provided at the front end of the wind tunnel experimental section 8. The experimental piece 9 is set on a measuring structure 10 of the wind tunnel experimental section 8. A force sensor 5 is provided on the measuring structure 10. The force sensor 5 is connected to a force acquisition computer 7 through a force acquisition module 6. The low-speed wind tunnel 1 is also provided with a wind tunnel control computer 3.

[0037] 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 differential pressure transducer reading through the sensors, and then calculates the standard wind speed in the wind tunnel. Based on 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. The frequency converter controls the motor speed to change the rotation speed of the wind tunnel fan, thereby achieving control of the wind speed in the wind tunnel; by controlling the wind speed in the wind tunnel, the flow velocity of the rolling element in the experimental piece 9 is controlled to simulate the revolution motion of the rolling element in the bearing at different speeds. The force sensor 5 is used to measure the drag resistance of the bearing rolling element 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.

[0038] like Figure 4 As shown, 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 long and has a cross-section of a square of 0.3 m × 0.3 m. Wind tunnel observation windows 30 for observation are provided 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.

[0039] like Figure 2 、 3 As shown in Figure 4, the measuring structure 10 includes a vertical support 22 mounted on a horizontal 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 provided at the upper end of the swing rod 25, and the lower end of the swing rod 25 is connected to the measured rolling element 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 mounted on the sensor bracket 28, and the force sensor 5 is fixed on the sensor bracket 27.

[0040] The horizontal 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 horizontal support 31 by bolts. A plurality of bolt holes 32 are reserved on the horizontal support 31 to meet the fixation of 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 set on the upper part of the vertical support 22 to support the swing shaft 24 of the 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 element support rod 17 by bolts. Due to the different force arm lengths of the swing rod 25, the drag resistance of the measured rolling element 16 on the measured rolling element support rod 17 is amplified. The sensor bracket 28 is installed on the vertical support 22 by bolts, and the sensor support 27 is installed on the sensor bracket 28 by bolts. 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 element 16, which is convenient for measurement and reduces experimental errors.

[0041] The experimental piece 9 includes a rolling body support seat 13 , on which a plurality of rolling bodies 16 to be tested are arranged through 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 through an acrylic plate support module 12 .

[0042] The acrylic plate support module 12 is fixed to the rolling element 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 element 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 element 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 element support seat 13 is reserved with multiple rolling element installation holes 14 for fixing the positions of the rolling element 16 to be tested and the rolling elements 18 arranged in parallel. By using different rolling element installation holes 14, the experimental piece installation positioning holes 15 are used to fix the positions of the rolling element 16 to be tested and the rolling elements 18 arranged in parallel. 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; parallel rolling element support rods 21 are installed on both sides of the parallel rolling elements 18, so that the parallel rolling elements 18 are mounted 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 rolling element support rods 21, and the retaining frame fixing module 20 fixes the retaining frame 19 with bolts; the experimental piece 9 can provide a flow environment for the measured rolling element 16 that simulates the actual situation in the bearing.

[0043] The interval between two adjacent holes of the multiple rolling body mounting holes 14 is 130 mm, the diameter of the rolling body mounting hole 14 is 10 mm, the diameter of the experimental piece mounting positioning hole 15 is 5 mm, the diameter of the tested rolling body support rod 17 is 5 mm, and the diameter of the parallel arranged rolling body support rod 21 is 10 mm.

[0044] 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:

[0045] (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 the accurate wind speed measurement;

[0046] (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 with 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 measurement structure 10 with 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;

[0047] (3) Check whether there are any foreign objects in the low-speed wind tunnel 1, check whether the test piece 9 is installed properly, whether the tested rolling element support rod 17 of the tested rolling element 16 is suspended in the air, and whether the other end of the force amplification structure contacts the pressure sensor 5;

[0048] (4) Open the force acquisition computer software, turn on the data recording function, and prepare to collect force;

[0049] (5) Start the low-speed wind tunnel 1 and control the wind speed by controlling the frequency. After the wind speed changes stabilize, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer 3;

[0050] (6) Change the fan operating frequency in sequence and measure the value of force sensor 5 at different incoming wind speeds;

[0051] (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 acquisition software is closed. This completes the measurement experiment of the drag resistance of the bearing rolling element of one structural form;

[0052] (8) Remove the experimental piece 9, change the structure of the experimental piece as required, repeat steps 2 to 8, and conduct the experiment of the next structural form;

[0053] (9) The drag resistance data collected by the force sensor 5 is exported and processed.

[0054] The experimental data processing process in the ninth step includes the following steps:

[0055] 1) For the measurement results at any wind speed, after the sensor reading stabilizes, 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;

[0056] 2) Analyze the experimental measurement results, identify unreasonable data and eliminate them;

[0057] 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 at the wind speed.

[0058] A device and method for measuring the drag resistance of bearing rolling elements is described. During the test, the rolling elements are constantly tangent to the inner and outer raceways during bearing operation. Therefore, the experimental device design ignores the curvature of the bearing's inner and outer rings, converting the annular cavity into a flat interlayer space. Furthermore, during bearing operation, the drag resistance experienced by the rolling element is also affected by the adjacent rolling elements in front and behind. This experimental device features parallel installation of rolling elements of the same size in front and behind the rolling element under test. These elements, along with upper and lower acrylic plates, create flow conditions around the rolling element within the bearing. In wind tunnel simulations, single-phase fluid flow is used to simulate the two-phase oil-gas flow within the bearing. Due to the actual wind speed and flow conditions in the wind tunnel, the drag experienced by a single rolling element is very small. To reduce errors and facilitate measurement, this device incorporates a novel measurement scheme using a lever-based force amplification measurement structure to amplify the drag resistance experienced by the rolling element under test. One end of the force amplification structure is bolted to the rolling element under test, which is suspended in the wind tunnel by a support. The other end is connected to the rolling element through a crossbar, which contacts a 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.

[0059] 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 in the scope of protection 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 of suitable wind speed for an experimental piece (9), wherein 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 provided at the front end of the wind tunnel experimental section (8), the experimental piece (9) is provided on a measuring structure (10) of the wind tunnel experimental section (8), a force sensor (5) is provided on the measuring structure (10), the force sensor (5) is connected to a force acquisition computer (7) via a force acquisition module (6), and a wind tunnel control computer (3) is also provided on the low-speed wind tunnel (1); The measuring structure (10) includes a vertical support (22) mounted on a transverse support (31), a swing shaft (24) mounted on the vertical support (22) through a swing shaft mounting hole (23), a swing rod (25) mounted on the swing shaft (24), a cross bar (26) provided at the upper end of the swing rod (25), and a lower end of the swing rod (25) connected to a measured rolling element support rod (17) on a wind tunnel wall (29), a sensor bracket (28) further provided on the vertical support (22), the sensor bracket (27) mounted on the sensor bracket (28), and a force sensor (5) fixed on the sensor bracket (27); The experimental piece (9) includes a rolling body support seat (13), a plurality of rolling bodies (16) to be tested are arranged on the rolling body support seat (13) through a retaining frame (19) and a rolling body support rod (17), and an acrylic plate (11) is installed on the rolling body support seat (13) through an acrylic plate support module (12).

2. The bearing rolling element drag resistance test and measurement device according to 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 differential pressure variable reading 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 motor speed is controlled by the frequency converter to change the rotation speed of the wind tunnel fan, thereby achieving 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 at different speeds in the bearing. 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 then 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.

3. A bearing rolling element drag resistance test and measurement device according to 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 provided 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. The bearing rolling element drag resistance test and measurement device according to claim 3, 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 the rolling body at different positions. The swing shaft mounting hole (23) is set on the upper part of the vertical support (22) to support the swing shaft (24) of the force amplification structure. The swing shaft (24) serves as the fulcrum of the lever structure. The swing shaft (24) is mounted on the circular 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 element support rod (17) by a bolt. Due to the different force arm lengths of the swing rod (25), the drag resistance of the measured rolling element (16) on the measured rolling element support rod (17) is amplified. The sensor bracket (28) is mounted on the vertical support (22) by bolts, and the sensor bracket (27) is mounted on the sensor bracket (28) by bolts. The force sensor (5) is fixed to the sensor bracket (27) by bolts. After the sensor is installed, the sensor height is consistent with the height of the crossbar (26).

5. The bearing rolling element drag resistance test and measurement device according to claim 4, characterized in that: The acrylic plate support module (12) is fixed to the rolling element 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 element (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 element 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), and are used to install and fix the experimental piece in the wind tunnel test section (8); a plurality of rolling element installation holes (14) are reserved on the rolling element support seat (13) for fixing the positions of the rolling element (16) to be tested and the rolling elements (18) arranged in parallel, and by using different rolling element installation holes (14) to implement The invention relates to a method for measuring drag resistance under conditions of different numbers of rolling elements and spacing between rolling elements; a rolling element support rod (17) to be measured is installed on both sides of the rolling element (16) to be measured, and the rolling element support rod (17) to be measured passes through the rolling element mounting hole (14) on the rolling element support seat (13) and is connected to the measuring structure (10), so that the rolling element (16) to be measured is suspended in the air without contacting other structures; rolling element support rods (21) to be arranged in parallel are installed on both sides of the rolling elements (18), so that the rolling elements (18) to be arranged in parallel are installed in the rolling element mounting hole (14), providing a flow environment for the rolling elements (16) to be measured; a retainer (19) is placed on the rolling element support rods (21) to be arranged in parallel, and a retainer fixing module (20) fixes the retainer (19) by bolts; the experimental piece (9) can provide a flow environment for the rolling element (16) to be measured that simulates the actual situation in the bearing.

6. The bearing rolling element drag resistance test and measurement device according to claim 5, 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 experimental 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.

7. A method for measuring the drag resistance of a bearing rolling element according to claim 1, 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 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); 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 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); Step 4: Open the force acquisition computer software, turn on the data recording function, and prepare to collect force; Step 5: Start the low-speed wind tunnel (1), control the wind speed by controlling the frequency, and after the wind speed changes stabilize, record the wind speed and force sensor values ​​displayed by the wind tunnel control computer (3); Step 6: Change the fan operating frequency in sequence and measure the value of the force sensor (5) at different incoming wind speeds; Step 7: After data collection is completed, gradually reduce the wind tunnel wind speed. After the wind tunnel stops running, turn off the wind tunnel and the force sensor data acquisition software. This completes the measurement experiment of the rolling element drag resistance of a bearing structure. Step 8: Remove the experimental piece (9), change the structure of the experimental piece according to the requirements, repeat steps 2 to 8, and conduct the experiment of the next structural form; In the ninth step, the drag resistance data collected by the force sensor (5) is exported and processed.

8. A bearing rolling element drag resistance experimental measurement method according to claim 7, 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 reading stabilizes, 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 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 at the wind speed.

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