Lubricant oil film shear force detection equipment and oil film shear force dual measurement method

Abstract

A device for detecting the shear force of a lubricant oil film and a dual measurement method for the shear force of the oil film relate to the field of measurement and control technology. The present invention solves the problems of low measurement accuracy of the shear force of the lubricant oil film and weak working condition capability of measuring the shear force of the oil film in existing lubricant oil film shear force detection equipment. The lower part of the ring drive mechanism of the present invention is fixedly connected to the upper part of the loading device, the lower part of the ball drive mechanism is fixedly connected to the upper part of the support device, the sample cavity is installed on the table of the bench mechanical structure, the ball specimen and the ring specimen are both arranged in the sample cavity, the ball specimen is located in the groove of the ring specimen, the ball specimen is in line contact with the ring specimen, the ring drive mechanism and the ball drive mechanism respectively drive the ball specimen and the ring specimen to rotate, when there is a certain speed difference between the ball and the ring and the oil film is subjected to shear, the shear force of the oil film is measured. The present invention is used for dual measurement of the shear force of the oil film to make the measurement result more accurate.

Description

Technical Field

[0001] The present invention relates to the field of measurement and control technology, and in particular to a device for detecting lubricant oil film shear force and a dual measurement method for oil film shear force. Background Art

[0002] Bearing slip is a key cause of bearing failure. Insufficient oil film shear force can lead to bearing slip, which affects the reliability and life of the bearing. Oil film shear force is essentially a rheological property of the lubricant. Therefore, to accurately characterize the mechanical properties of oil film shear force, it is crucial to develop lubricant film shear force testing equipment that simulates the relative motion and forces between bearing rolling elements and rings and measures the mechanical properties of oil film shear force.

[0003] Currently, existing lubricant film shear force testing equipment has the following limitations: 1. No equipment exists that can simulate the contact and motion between the rolling elements and rings of angular contact ball bearings. 2. The accuracy of lubricant film shear force measurement needs to be further improved. 3. The operating conditions under which lubricant film shear force can be measured need to be further enhanced. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of low lubricant oil film shear force measurement accuracy and weak working condition capability of measuring oil film shear force in existing lubricant oil film shear force detection equipment, and further provide a lubricant oil film shear force detection equipment and a dual measurement method of oil film shear force.

[0005] The technical solution of the present invention is:

[0006] A device for detecting the shear force of a lubricant oil film comprises a ball and ring friction pair test piece, a driving device, a sensor for measuring the oil film shear force, a supporting device, a loading device and a bench mechanical structure. The ball and ring friction pair test piece is arranged above the middle of the bench mechanical structure table. The driving device comprises a ring driving mechanism and a ball driving mechanism. The ring driving mechanism and the ball driving mechanism are respectively arranged on both sides of the ball and ring friction pair test piece. The ring driving mechanism is installed on the bench mechanical structure table. The sensor for measuring the oil film shear force is installed on the side of the ring driving mechanism. A loading device is provided below the ring driving mechanism. The lower part of the driving mechanism is fixedly connected to the upper part of the loading device, the loading device is installed on the bottom plate of the bench mechanical structure, a supporting device is provided under the ball driving mechanism, the lower part of the ball driving mechanism is fixedly connected to the upper part of the supporting device, the supporting device is installed on the table of the bench mechanical structure, the ball and ring friction pair specimen includes a ball specimen, a ring specimen and a specimen cavity, the specimen cavity is installed on the table of the bench mechanical structure, the ball specimen and the ring specimen are both arranged in the specimen cavity, the ball specimen is located in the groove of the ring specimen, the ball specimen is in line contact with the ring specimen, the ring driving mechanism and the ball driving mechanism respectively drive the ball specimen and the ring specimen to rotate.

[0007] Furthermore, the loading device includes a servo electric cylinder, a load sensor, a damping adjustment device, an air floating pad and an air floating bearing. The air floating bearing, the air floating pad, the damping adjustment device, the load sensor and the servo electric cylinder are arranged in sequence from top to bottom in the vertical direction directly below the ring drive mechanism. The servo electric cylinder is installed on the bottom plate of the test bench mechanical structure. The lower end face of the load sensor is fixedly connected to the upper end face of the servo electric cylinder. The damping adjustment device is installed on the upper end face of the load sensor. The air floating pad is coaxially fixedly connected to the damping adjustment device. There is a gap between the coaxial disc of the air floating pad and the lower end of the air floating bearing. The air floating bearing is installed on the table of the test bench mechanical structure.

[0008] Furthermore, the damping adjustment device includes a buffer sleeve, a spring and a buffer rod. The buffer rod is installed on the upper end surface of the load sensor. The upper end of the spring is clearance-fitted with the raised outer circular surface of the buffer sleeve, and the lower end of the spring is clearance-fitted with the inner circular surface of the buffer rod. The buffer sleeve and the buffer rod are clearance-fitted, and the air floating pad is coaxially fixedly connected to the buffer sleeve.

[0009] Furthermore, the ring drive mechanism includes an electric spindle, an electric spindle fixing part, a transmission spindle and a bracket. The electric spindle fixing part is fixedly connected to the upper end surface of the air bearing. The electric spindle is installed above the electric spindle fixing part. One end of the transmission spindle is coaxially fixedly connected to the electric spindle. The other end of the transmission spindle is fixedly connected to the ring specimen. The upper end of the bracket is coaxially matched with the transmission spindle, and the lower end of the bracket is installed on the table of the bench mechanical structure.

[0010] Furthermore, the loading device also includes a counterweight assembly, which includes a weight rack and several weight plates. The weight rack is an L-shaped rod structure. The end of the transverse rod of the weight rack is fixedly connected to one end of the electric spindle. The end of the longitudinal rod of the weight rack is provided with a support plate, and the weight plate is installed on the longitudinal rod of the weight rack.

[0011] Furthermore, the supporting device includes a servo electric cylinder 2 and a screw lifting platform. The screw lifting platform includes a lifting platform body, a movable support plate and multiple hinges. One end of the movable connecting plate is hinged to one end of the upper end surface of the fixed support plate on the top of the lifting platform body through a hinge. The servo electric cylinder 2 11 is tilted and arranged between the fixed support plate and the movable connecting plate. The bottom of the servo electric cylinder 2 is hinged to the other end of the upper end surface of the fixed support plate through a hinge. The protruding end of the servo electric cylinder 2 is hinged to the lower end surface of the movable connecting plate through a hinge.

[0012] Furthermore, the ball drive mechanism includes an electric spindle 2, an electric spindle fixing part 2, a transmission spindle 2 and a bracket 2. The electric spindle fixing part 2 is fixedly connected to the upper end surface of the screw lifting platform. The electric spindle 2 is installed above the electric spindle fixing part 2. One end of the dynamic spindle 2 is coaxially fixedly connected to the electric spindle 2, and the other end of the transmission spindle 2 is fixedly connected to the ball specimen. The upper end of the bracket 2 is coaxially matched with the transmission spindle 2, and the lower end of the bracket 2 is installed on the table of the test bench mechanical structure.

[0013] Furthermore, it also includes a data acquisition, monitoring and storage system, which includes pressure sensor 1, pressure sensor 2, speed sensor 1, speed sensor 2, temperature sensor 1, temperature sensor 2 and torque sensor. Pressure sensor 1 and pressure sensor 2 are respectively installed between servo electric cylinder 1 and damping adjustment device and on the side of electric spindle 1, and are respectively used to measure the load applied by servo electric cylinder 1 and oil film shear force; temperature sensor 1 and temperature sensor 2 are respectively installed on lubricating oil inlet pipe and ring specimen, and are respectively used to measure lubricating oil supply temperature and contact area temperature of ball and ring friction pair specimen; speed sensor 1 and speed sensor 2 are respectively installed on the axial surface of electric spindle 1 and electric spindle 2, and are respectively used to monitor the speed of electric spindle 1 and electric spindle 2 in real time; one end of the torque sensor is fixedly connected to the axial end of electric spindle 2, and the other end of the torque sensor is fixedly connected to transmission spindle 2, and is used to measure the oil film shear force in the contact area of ball and ring friction pair specimen.

[0014] Furthermore, it also includes a circulating lubrication system, which includes an oil tank, a nozzle, an oil supply line, an oil return line and two oil pumps. The oil tank is located directly below the sample cavity and is mounted on the lower end surface of the bench mechanical structure. The sample cavity is a rectangular box body, which is mounted on the bench mechanical structure. A transmission spindle mounting hole 1 is provided on the box wall on one side of the sample cavity, which is clearance-matched with the transmission spindle 1. The transmission spindle mounting hole 1 is a circular hole, and one end of the transmission spindle coaxially passes through the transmission spindle mounting hole 1 and is coaxially fixedly connected to the ring specimen. The sample A second transmission main shaft mounting hole which is clearance-matched with the second transmission main shaft is provided on the box wall on the other side of the cavity. The second transmission main shaft mounting hole is an elongated hole with the major axis arranged in the vertical direction. The two ends of the transmission main shaft pass through the second transmission main shaft mounting hole and are fixedly connected to the ball specimen. A nozzle is installed on the side wall of the specimen cavity. The nozzle head faces the contact area of the ball and ring friction pair specimen. The oil inlet of the nozzle is connected to the oil outlet of the oil tank through an oil supply pipeline. The oil outlet at the bottom of the specimen cavity is connected to the oil inlet of the oil tank through an oil return pipeline. Oil pumps are installed on both the oil supply pipeline and the oil return pipeline.

[0015] A dual measurement method for oil film shear force, the dual measurement method for oil film shear force is based on the lubricant oil film shear force detection device, and the method is implemented by the following steps:

[0016] Step 1: Adjust the posture of the ball specimen:

[0017] During the measurement, the height of the screw lifting platform is adjusted to adjust the height of the electric spindle 2, and the posture of the ball test piece is adjusted by the servo electric cylinder 2 to simulate the contact state between the ball and the ring of the angular contact ball bearing under different rotation angles.

[0018] Step 2: Formation of oil film:

[0019] Start the oil pump to spray the lubricating oil in the oil tank through the nozzle to the contact area of the ball and ring friction pair test piece, thereby forming an oil film;

[0020] Step 3: Adjust the contact area between the ball and the ring:

[0021] Start the first and second electric spindles and adjust their speeds so that the contact area of the ball and ring friction pair specimen is in a pure rolling state. At the same time, start the industrial water cooler to dissipate heat from the first and second electric spindles.

[0022] Step 4: Apply load to the contact area between the ball and the ring:

[0023] Drive the servo electric cylinder 1 and turn on the air pump to supply air to the air bearing to complete the support of the electric spindle 1. By adjusting the weight of the weight plate, load is applied to the contact area of the ball and ring friction pair test piece to ensure that the electric spindle 1 does not generate overturning torque;

[0024] Step 5: Generate elastohydrodynamic oil film shear force:

[0025] Under certain load and rotation speed conditions and with sufficient lubrication, an elastohydrodynamic oil film of a certain thickness can be formed between the ball specimen and the ferrule specimen. By adjusting the rotation speeds of the first and second electric spindles, the linear velocities of the contact points of the ball specimen and the ferrule specimen are made different, thereby forming a certain sliding speed difference. In this way, the corresponding elastohydrodynamic oil film shear force can be generated on the contact surface.

[0026] Step 6: Measure the oil film shear force:

[0027] Under the action of the oil film shear force, the air bearing deflects. At this time, the second pressure sensor at the same height as the oil film shear force can display the value of the oil film shear force. At the same time, the torque generated by the oil film shear force can also be measured by the torque sensor installed on the second transmission main shaft, thus realizing the dual measurement of the oil film shear force.

[0028] Compared with the prior art, the present invention has the following effects:

[0029] 1. The lubricant film shear force testing device of the present invention utilizes a ball and ring pair to simulate the contact between the ball and ring in the primary load-bearing area of deep groove ball bearings and angular contact ball bearings. Furthermore, when simulating angular contact ball bearings, the device can measure and study the oil film shear force after lubricant entrainment at different rotation angles by adjusting the lead screw lifting platform and servo electric cylinder.

[0030] 2. The lubricant oil film shear force detection device of the present invention can dually measure oil film shear force, making the measurement results more accurate. On the one hand, the oil film shear force is transmitted to the second transmission spindle through the contact area of the ball-ring friction pair test piece, and then transmitted to the torque sensor through the second transmission spindle. On the other hand, the oil film shear force is also transmitted to the first transmission spindle through the contact area of the ball-ring friction pair test piece, and then transmitted to the first motorized spindle through the first motorized spindle, and finally transmitted to the oil film shear force sensor (pressure sensor 2) through the first motorized spindle.

[0031] 3. The lubricant film shear force detection device of the present invention improves the stability of oil film shear force measurement by incorporating a damping adjustment device into the loading mechanism. Since servo electric cylinder 1 uses rigid loading, the lead screw of servo electric cylinder 1 may reach zero elevation during loading, causing a sharp increase in loading force, potentially overloading and damaging other components. Therefore, a flexible damping adjustment device is incorporated. When the lead screw of servo electric cylinder 1 reaches zero elevation, the load compresses the spring, thereby achieving a buffering effect.

[0032] 4. The lubricant film shear force detection device of the present invention incorporates an air bearing within the loading device. This allows the first motorized spindle to rotate about its axis and move axially when air is introduced into the bearing, with negligible horizontal friction torque. Furthermore, the use of a high-resolution mechanical sensor allows for measurement accuracy of up to 0.02% for lubricant film shear force. Furthermore, the use of a high-speed motorized spindle and air bearing for loading enhances the ability to measure lubricant film shear force. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a lubricant oil film shear force detection device according to the present invention;

[0034] Figure 2 It is a schematic structural diagram of the damping adjustment device in the lubricant oil film shear force detection device of the present invention;

[0035] Figure 3 This is a schematic diagram of the oil film shear force measurement principle of the present invention (a side view of a device for detecting lubricant oil film shear force);

[0036] Figure 4 This is a schematic diagram of the oil film shear force measurement principle of the present invention (a top view of the lubricant oil film shear force detection device);

[0037] Figure 5 It is a structural block diagram of the data acquisition system of the present invention.

[0038] In the figure: 1. Mechanical structure of the test bench; 2. Support device; 3. Sensor for measuring oil film shear force; 4. Loading device; 5. Electric spindle 1; 6. Electric spindle fixing part 1; 7. Transmission spindle 1; 8. Transmission spindle 2; 9. Electric spindle 2; 10. Electric spindle fixing part 2; 11. Servo electric cylinder 2; 12. Screw lifting platform; 13. Ball test piece; 14. Ring test piece; 15. Bracket 1; 16. Bracket 2; 17. Servo electric cylinder 1; 18. Load sensor; 19. Damping adjustment device; 20. Air cushion; 21. Air bearing; 22. Counterweight assembly; 23. Ball and ring friction pair test piece; 24. Buffer sleeve; 25. Spring; 26. Buffer rod. DETAILED DESCRIPTION

[0039] Specific implementation method 1: Combination Figure 1 and Figure 2 Description of the present embodiment. This embodiment is a device for detecting the shear force of a lubricant oil film. It includes a ball and ring friction pair test piece 23, a driving device, a sensor for measuring the oil film shear force 3, a supporting device 2, a loading device 4 and a bench mechanical structure 1. The ball and ring friction pair test piece 23 is arranged above the middle of the bench mechanical structure 1. The driving device includes a ring driving mechanism and a ball driving mechanism. The ring driving mechanism and the ball driving mechanism are respectively arranged on both sides of the ball and ring friction pair test piece 23. The ring driving mechanism is installed on the bench mechanical structure 1. The sensor for measuring the oil film shear force 3 is installed on the side of the ring driving mechanism. A loading device 4 is provided below the ring driving mechanism. The lower part of the mechanism is fixedly connected to the upper part of the loading device 4, and the loading device 4 is installed on the bottom plate of the bench mechanical structure 1. A supporting device 2 is provided under the ball driving mechanism, and the lower part of the ball driving mechanism is fixedly connected to the upper part of the supporting device 2. The supporting device 2 is installed on the table of the bench mechanical structure 1. The ball and ring friction pair specimen 23 includes a ball specimen 13, a ring specimen 14 and a specimen cavity. The specimen cavity is installed on the table of the bench mechanical structure 1. The ball specimen 13 and the ring specimen 14 are both arranged in the specimen cavity. The ball specimen 13 is located in the groove of the ring specimen 14. The ball specimen 13 is in line contact with the ring specimen 14. The ring driving mechanism and the ball driving mechanism respectively drive the ball specimen 13 and the ring specimen 14 to rotate.

[0040] In this embodiment, the ball-ring friction pair test piece 23 is designed by simulating the structure of a deep groove ball bearing or an angular contact ball bearing, and is a core mechanism for testing the shear force of the lubricating oil film.

[0041] Specific implementation method 2: Combination Figure 1 and Figure 2To describe this embodiment, the loading device 4 of this embodiment includes a servo electric cylinder 17, a load sensor 18, a damping adjustment device 19, an air cushion 20 and an air bearing 21. The air bearing 21, the air cushion 20, the damping adjustment device 19, the load sensor 18 and the servo electric cylinder 17 are arranged in sequence from top to bottom in the vertical direction directly below the ring drive mechanism. The servo electric cylinder 17 is installed on the bottom plate of the table mechanical structure 1. The lower end face of the load sensor 18 is fixedly connected to the upper end face of the servo electric cylinder 17. The damping adjustment device 19 is installed on the upper end face of the load sensor 18. The air cushion 20 is coaxially fixedly connected to the damping adjustment device 19. There is a gap between the coaxial disc of the air cushion 20 and the lower end of the air bearing 21. The air bearing 21 is installed on the table of the table mechanical structure 1. With this arrangement, the load is transmitted from servo electric cylinder 17 to load sensor 18, which then transmits it to damping adjustment device 19. From there, it is transferred to air cushion 20, causing it to move upward. Air cushion 20, through its air film, transfers the load to air bearing 21, thereby supporting electric spindle 5. With air flowing through air bearing 21, electric spindle 5 can both rotate about its axis and move axially, with negligible horizontal friction torque. Other components and connections are identical to those in Specific Embodiment 1.

[0042] In this embodiment, the air bearing 21 can adopt the AB-R250 air bearing produced by Shanghai Xiyu Automation Technology Co., Ltd.

[0043] In this embodiment, the servo electric cylinder 17 is fixed to the bottom plate of the bench mechanical structure 1 by screws; the bottom surface of the load sensor 18 is threadedly connected to the protruding end of the servo electric cylinder 17, and the top of the load sensor 18 is fixedly connected by screws and a buffer rod 26; the disc at the lower end of the air bearing 21 is coaxially matched with the upper end of the air cushion 20, and the air cushion 20 plays an axial bearing role. The upper end of the air bearing 21 is fixed to the table of the bench mechanical structure 1 by screws.

[0044] Specific implementation method three: Combination Figure 1 and Figure 2To explain this embodiment, the damping adjustment device 19 of this embodiment includes a buffer sleeve 24, a spring 25, and a buffer rod 26. The buffer rod 26 is mounted on the upper end face of the load sensor 18. The upper end of the spring 25 is in clearance with the raised outer circumference of the buffer sleeve 24, and the lower end of the spring 25 is in clearance with the inner circumference of the buffer rod 26. The buffer sleeve 24 and the buffer rod 26 are in clearance, and the air cushion 20 is coaxially fixedly connected to the buffer sleeve 24. With this arrangement, since the servo electric cylinder 17 is loaded in a rigid manner, the lead screw of the servo electric cylinder 17 may rise to zero during the loading process, resulting in a sharp increase in the loading force, thereby causing overload and damage to other components. Therefore, a damping adjustment device 19 with flexible loading is added. When the lead screw of the servo electric cylinder 17 rises to zero, the load can compress the spring 25, thereby achieving a buffering effect. Other components and connection relationships are the same as those of the specific embodiment one or two.

[0045] In this embodiment, the buffer sleeve 24 and the air cushion 20 are fixed by screws.

[0046] Specific implementation method four: Combination Figure 1 and Figure 2 To describe this embodiment, the ring drive mechanism of this embodiment includes an electric spindle 5, an electric spindle fixture 6, a transmission spindle 7, and a bracket 15. The electric spindle fixture 6 is fixedly connected to the upper end surface of the air bearing 21. The electric spindle 5 is installed above the electric spindle fixture 6. One end of the transmission spindle 7 is coaxially fixedly connected to the electric spindle 5, and the other end of the transmission spindle 7 is fixedly connected to the ring specimen 14. The upper end of the bracket 15 is coaxially matched with the transmission spindle 7, and the lower end of the bracket 15 is installed on the table of the bench mechanical structure 1. With this arrangement, the ring drive mechanism is used to drive the ring specimen 14 to rotate. The load is applied to the contact area between the ball and the ring through the electric spindle 5. The other components and connection relationships are the same as those of the specific embodiments one, two, or three.

[0047] In this embodiment, the electric spindle fixture 6 is screwed onto the upper end surface of the air bearing 21 in the loading device 4. One end of the transmission spindle 7 is keyed to the electric spindle 5, and the other end of the transmission spindle 7 is fixedly engaged with the ring test piece 14.

[0048] Specific implementation method five: Combination Figure 1 and Figure 2To explain this embodiment, the loading device 4 also includes a counterweight assembly 22, which consists of a weight rack and several weight plates. The weight rack is an L-shaped rod structure, with the ends of its transverse members fixedly connected to the ends of the motorized spindle 5. The ends of its longitudinal members are provided with support plates, and the weight plates are mounted on the longitudinal members of the weight rack. This arrangement secures the counterweight assembly 22 to the motorized spindle 5, primarily to prevent the motorized spindle 5 from generating a tipping moment under high load. The remaining components and connections are identical to those in Specific Embodiments 1, 2, 3, or 4.

[0049] Specific implementation method six: combination Figure 1 and Figure 2 To describe this embodiment, the support device 2 of this embodiment includes a servo electric cylinder 11 and a screw lifting platform 12. The screw lifting platform 12 includes a lifting platform body, a movable support plate, and multiple hinges. One end of the movable connecting plate is hinged to one end of the upper end surface of the fixed support plate at the top of the lifting platform body through a hinge. The servo electric cylinder 11 is tilted and arranged between the fixed support plate and the movable connecting plate. The bottom of the servo electric cylinder 11 is hinged to the other end of the upper end surface of the fixed support plate through a hinge. The extended end of the servo electric cylinder 11 is hinged to the lower end surface of the movable connecting plate through a hinge. With this arrangement, when measuring, the height of the screw lifting platform 12 is adjusted to adjust the height of the electric spindle 9. The posture of the ball test piece 13 is adjusted by the servo electric cylinder 11, thereby simulating the contact state between the ball and the ring of the angular contact ball bearing when the ball rotates at different angles. The other components and connection relationships are the same as those of the specific embodiments one, two, three, four or five.

[0050] In this embodiment, the screw lifting platform 12 can adopt a shear-type electric screw lifting platform produced by Suzhou Xunte Hydraulic Lifting Machinery Co., Ltd.

[0051] Specific implementation method seven: combination Figure 1 and Figure 2 To describe this embodiment, the ball drive mechanism includes an electric spindle 9, an electric spindle fixture 10, a transmission spindle 8, and a bracket 16. The electric spindle fixture 10 is fixedly connected to the upper end surface of the screw lift platform 12. The electric spindle 9 is mounted above the electric spindle fixture 10. One end of the dynamic spindle 8 is coaxially fixedly connected to the electric spindle 9, and the other end of the transmission spindle 8 is fixedly connected to the ball test piece 13. The upper end of the bracket 16 is coaxially matched with the transmission spindle 8, and the lower end of the bracket 16 is mounted on the table of the stand mechanical structure 1. With this arrangement, the ball drive mechanism is used to drive the ball test piece 13 to rotate. The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, or sixth embodiments.

[0052] In this embodiment, the second motorized spindle fixture 10 is screwed to the fixed support plate within the support device 2. One end of the second transmission spindle 8 is keyed to the second motorized spindle 9, while the other end of the second transmission spindle 8 is fixedly engaged with the ball test piece 13. The upper end of the second bracket 16 is coaxially engaged with the second transmission spindle 8, while the lower end of the bracket 16 is screwed to the upper surface of the movable connecting plate.

[0053] Specific implementation method eight: combination Figure 1 and Figure 2 To explain this embodiment, this embodiment also includes a data acquisition, monitoring and storage system, which includes pressure sensor 1, pressure sensor 2, speed sensor 1, speed sensor 2, temperature sensor 1, temperature sensor 2 and torque sensor. Pressure sensor 1 and pressure sensor 2 are respectively installed between servo electric cylinder 17 and damping adjustment device 19 and on the side of electric spindle 15, and are respectively used to measure the load applied by servo electric cylinder 17 and the oil film shear force; temperature sensor 1 and temperature sensor 2 are respectively installed on the lubricating oil inlet pipe and the ring specimen 14, and are respectively used to measure the lubricating oil supply temperature and the contact area temperature of the ball and ring friction pair specimen 23; speed sensor 1 and speed sensor 2 are respectively installed on the axial surface of electric spindle 15 and electric spindle 2 9, and are respectively used to monitor the speed of electric spindle 15 and electric spindle 2 9 in real time; one end of the torque sensor is fixedly connected to the axial end of electric spindle 2 9, and the other end of the torque sensor is fixedly connected to the transmission spindle 2 8, and is used to measure the oil film shear force in the contact area of the ball and ring friction pair specimen 23. With this setup, speed sensors 1 and 2 ensure the accuracy of the speed data required for testing and monitor changes in the electric spindle speed during the test in real time. Pressure sensor 1, mounted above servo electric cylinder 17, ensures the accuracy of the loading force, while pressure sensor 2, mounted on electric spindle 1, measures the shear force of the oil film. Temperature sensor 1, mounted on the oil supply port, measures and monitors the oil supply temperature in real time. Temperature sensor 2, mounted on the ferrule, indirectly measures the contact zone temperature. Other components and connections are identical to those in Specific Embodiments 1, 2, 3, 4, 5, 6, or 7.

[0054] In this embodiment, each of these sensors is powered by a switching power supply, with signals transmitted to the control computer via an acquisition card. The data acquisition, monitoring, and storage system primarily utilizes a combination of hardware and LABVIEW software to record, process, display, and store data on lubricating oil film shear force, speed, load, and temperature.

[0055] Specific implementation method nine: Combination Figure 1Describe this embodiment, this embodiment also includes a circulating lubrication system, the circulating lubrication system includes an oil tank, a nozzle, an oil supply line, an oil return line and two oil pumps, the oil tank is located directly below the sample cavity, the oil tank is mounted on the lower end surface of the bench mechanical structure 1, the sample cavity is a rectangular box body, the rectangular box body is mounted on the bench mechanical structure 1, one side of the sample cavity box wall is provided with a transmission main shaft mounting hole 1 that is clearance-matched with the transmission main shaft 1 7, the transmission main shaft mounting hole 1 is a circular hole, the end of the transmission main shaft 1 7 coaxially passes through the transmission main shaft mounting hole 1 and is coaxially fixedly connected to the ring specimen 14 Next, the other side wall of the sample cavity is provided with a transmission main shaft mounting hole 2 that is clearance-matched with the transmission main shaft 2 8. The transmission main shaft mounting hole 2 is an elongated hole with its major axis arranged in the vertical direction. The end of the transmission main shaft 2 8 passes through the transmission main shaft mounting hole 2 and is fixedly connected to the ball specimen 13. A nozzle is installed on the side wall of the sample cavity, with the nozzle head facing the contact area of the ball and ferrule friction pair specimen 23. The oil inlet of the nozzle is connected to the oil outlet of the oil tank through an oil supply line, and the oil outlet at the bottom of the sample cavity is connected to the oil inlet of the oil tank through an oil return line. Oil pumps are installed on both the oil supply line and the oil return line. With this arrangement, the circulating lubrication system uses a side spray method to spray lubricating oil on the contact area of the ball and ferrule friction pair specimen 23. Other components and connection relationships are the same as those of specific embodiments one, two, three, four, five, six, seven or eight.

[0056] Specific implementation method ten: Combination Figure 1 、 Figure 2 and Figure 5 This embodiment describes a dual measurement method for oil film shear force. The dual measurement method for oil film shear force is implemented by the lubricant oil film shear force detection device. The method is implemented by the following steps:

[0057] Step 1: Adjust the posture of the ball test piece 13:

[0058] During measurement, the height of the screw lifting platform 12 is adjusted to adjust the height of the electric spindle 9, and the posture of the ball test piece 13 is adjusted by the servo electric cylinder 11, thereby simulating the contact state between the ball and the ring of the angular contact ball bearing under different rotation angles;

[0059] Step 2: Formation of oil film:

[0060] Start the oil pump to spray the lubricating oil in the oil tank through the nozzle to the contact area of the ball and ring friction pair test piece 23, thereby forming an oil film;

[0061] Step 3: Adjust the contact area between the ball and the ring:

[0062] Start the electric spindle 1 5 and the electric spindle 2 9 and adjust their rotation speeds so that the contact area between the ball and the ring friction pair specimen 23 is in a pure rolling state. At the same time, start the industrial water cooler to dissipate heat from the electric spindle 1 5 and the electric spindle 2 9.

[0063] Step 4: Apply load to the contact area between the ball and the ring:

[0064] Drive the servo electric cylinder 17 and turn on the air pump to supply air to the air bearing 21 to complete the support of the electric spindle 5. By adjusting the weight of the weight plate 22, a load is applied to the contact area of the ball and ring friction pair specimen 23 to ensure that the electric spindle 5 does not generate an overturning moment.

[0065] Step 5: Generate elastohydrodynamic oil film shear force:

[0066] Under certain load and rotation speed conditions and with sufficient lubrication, an elastohydrodynamic oil film of a certain thickness can be formed between the ball test piece 13 and the ferrule test piece 14. By adjusting the rotation speeds of the electric spindle 1 5 and the electric spindle 2 9, the linear velocities of the contact points of the ball test piece 13 and the ferrule test piece 14 are made different, thereby forming a certain sliding speed difference. In this way, a corresponding elastohydrodynamic oil film shear force can be generated on the contact surface.

[0067] Step 6: Measure the oil film shear force:

[0068] The oil film shear force causes air bearing 21 to deflect. Pressure sensor 2, at the same height as the oil film shear force, displays the shear force value. Simultaneously, the torque generated by the shear force can be measured by the torque sensor mounted on transmission spindle 2 8, achieving dual measurement of the shear force. The remaining components and connections are identical to those of embodiments 1, 2, 3, 4, 5, 6, 7, 8, or 9.

[0069] How it works

[0070] Combine Figures 1 to 5 The working principle of the lubricant oil film shear force detection device of the present invention is described as follows:

[0071] The oil film shear force between the ball and the ferrule causes the air bearing 21 to deflect. At this time, the oil film shear force sensor (pressure sensor 2) at the same height as the shear force will have a reading, which is the oil film shear force in the contact area between the ball and the ferrule. The vertical torque balance can prevent the torque overturning of the electric spindle 5 under high load conditions. The horizontal torque balance can achieve high-precision measurement of the oil film shear force.

[0072] For the analysis of the left main shaft (electric spindle 5), the load is transferred to the transmission main shaft 7 through the contact area of the ball and ring friction pair specimen 23, and then to the electric spindle 5 through the transmission main shaft 7, and then to the electric spindle fixing part 6 through the electric spindle fixing part 6, and then to the loading device 4 through the loading device 4, and finally to the gantry mechanical structure 1; for the analysis of the right main shaft (electric spindle 2 8), the load is transferred to the transmission main shaft 2 8 through the contact area of the ball and ring friction pair specimen 23, and then to the electric spindle 2 9 through the transmission main shaft 2 8, and finally to the gantry mechanical structure 1 through the loading device 4. The oil film shear force is further transmitted to the electric spindle fixing part 2 10 through the electric spindle fixing part 2 10, and then to the support device 2 through the support device 2, and finally to the test bench mechanical structure 1; the oil film shear force is transmitted to the transmission spindle 2 8 through the contact area of the ball and ring friction pair specimen 23, and is transmitted to the torque sensor through the transmission spindle 2 8; the oil film shear force is also transmitted to the transmission spindle 1 7 through the contact area of the ball and ring friction pair specimen 23, and is transmitted to the electric spindle 1 5 through the transmission spindle 1 7, and finally to the oil film shear force sensor (pressure sensor 2) through the electric spindle 1 5.

[0073] Further, if Figure 3 As shown, the electric spindle 2 9 drives the ball test piece 13 to rotate at a speed n1, and the servo electric cylinder 2 11 is adjusted to make the ball test piece 13 press the ring test piece 14 downward, thereby forming a contact load W between the ball test piece 13 and the ring test piece 14 接触载荷 The electric spindle 5 drives the ring test piece 14 at a speed n2. When the speeds n1 and n2 are different, the lubricant is sheared to form a real oil film shear force F. 真实的油膜剪切力 Under the support of the air bearing 21 with almost no friction torque, the actual oil film shear force F 真实的油膜剪切力 The electric spindle 5 is deflected as a whole by an angle α, and the electric spindle 5 is subjected to a certain real oil film shear force F 真实的油膜剪切力 Then, using the moment balance principle, knowing the rotation center of the air bearing 21 and the distance between l1 and l2, the actual oil film shear force F can be calculated. 真实的油膜剪切力 .

[0074] During the measurement process, if the contact load W is too large, the air bearing 21 is likely to generate an overturning moment, affecting the contact load measurement.

[0075] To ensure the accuracy of the measurement, it is necessary to add a counterweight assembly 22 to the tail of the electric spindle 5 supported by the air bearing 21, and then balance the torque to achieve accurate measurement of the oil film shear force. 配重 The product of the distance l3 from the counterweight assembly 22 to the rotation center is equal to the distance l4 from the center of the electric spindle 5 to the rotation center and the gravity G of the electric spindle 1. 5的重力The product of the distance from the contact center to the rotation center of the ball specimen 13 and the ring specimen 14 (l4+l5) and the contact load W 接触载荷 The product is balanced.

[0076] The moment balance of the test bench in the vertical direction is:

[0077] W 接触载荷 (l4+l5)+G 5的重力 l4-F 配重 l3=0

[0078] The moment balance of the test bench in the horizontal direction is:

[0079] F 真实的油膜剪切力 l1-F 所测的油膜剪切力 l2=0

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A device for detecting the shear force of a lubricant oil film, characterized in that: It includes a ball and ring friction pair test piece (23), a driving device, a sensor for measuring oil film shear force (3), a supporting device (2), a loading device (4) and a bench mechanical structure (1). The ball and ring friction pair test piece (23) is arranged above the middle of the bench mechanical structure (1). The driving device includes a ring driving mechanism and a ball driving mechanism. The ring driving mechanism and the ball driving mechanism are respectively arranged on both sides of the ball and ring friction pair test piece (23). The ring driving mechanism is installed on the bench mechanical structure (1). The sensor for measuring oil film shear force (3) is installed on the side of the ring driving mechanism. A loading device (4) is provided below the ring driving mechanism. The lower part of the ring driving mechanism is fixed to the upper part of the loading device (4). The loading device (4) is installed on the bottom plate of the bench mechanical structure (1), a support device (2) is provided below the ball driving mechanism, the lower part of the ball driving mechanism is fixedly connected to the upper part of the support device (2), the support device (2) is installed on the table of the bench mechanical structure (1), the ball and ring friction pair test piece (23) includes a ball test piece (13), a ring test piece (14) and a sample cavity, the sample cavity is installed on the table of the bench mechanical structure (1), the ball test piece (13) and the ring test piece (14) are both arranged in the sample cavity, the ball test piece (13) is located at the groove of the ring test piece (14), the ball test piece (13) and the ring test piece (14) are in line contact, the ring driving mechanism and the ball driving mechanism respectively drive the ball test piece (13) and the ring test piece (14). 3) and the ring specimen (14) rotate, the loading device (4) includes a servo electric cylinder (17), a load sensor (18), a damping adjustment device (19), an air floating pad (20) and an air floating bearing (21), the air floating pad (21), the air floating pad (20), the damping adjustment device (19), the load sensor (18) and the servo electric cylinder (17) are arranged in sequence from top to bottom in the vertical direction just below the ring driving mechanism, the servo electric cylinder (17) is installed on the bottom plate of the bench mechanical structure (1), the lower end surface of the load sensor (18) is fixedly connected to the upper end surface of the servo electric cylinder (17), the damping adjustment device (19) is installed on the upper end surface of the load sensor (18), the air floating pad (2 0) is coaxially fixedly connected to the damping adjustment device (19), a gap exists between the air floating pad (20) and the disc at the lower end of the air floating bearing (21), the air floating bearing (21) is mounted on the table of the bench mechanical structure (1), the damping adjustment device (19) includes a buffer sleeve (24), a spring (25) and a buffer rod (26), the buffer rod (26) is mounted on the upper end surface of the load sensor (18), the upper end of the spring (25) and the outer cylindrical surface of the buffer sleeve (24) are clearance matched, the lower end of the spring (25) and the inner cylindrical surface of the buffer rod (26) are clearance matched, the buffer sleeve (24) and the buffer rod (26) are clearance matched, and the air floating pad (20) is coaxially fixedly connected to the buffer sleeve (24).

2. The lubricant oil film shear force detection device according to claim 1, characterized in that: The ring driving mechanism includes an electric spindle (5), an electric spindle fixing part (6), a transmission spindle (7) and a bracket (15), the electric spindle fixing part (6) is fixedly connected to the upper end surface of the air bearing (21), the electric spindle (5) is installed above the electric spindle fixing part (6), one end of the transmission spindle (7) is coaxially fixedly connected to the electric spindle (5), the other end of the transmission spindle (7) is fixedly connected to the ring test piece (14), the upper end of the bracket (15) is coaxially matched with the transmission spindle (7), and the lower end of the bracket (15) is installed on the table of the bench mechanical structure (1).

3. The lubricant oil film shear force detection device according to claim 1, characterized in that: The loading device (4) further includes a counterweight assembly (22), which includes a weight rack and a plurality of weight discs. The weight rack is an L-shaped rod structure. The end of the transverse rod of the weight rack is fixedly connected to the end of the electric spindle (5). The end of the longitudinal rod of the weight rack is provided with a support plate, and the weight disc is installed on the longitudinal rod of the weight rack.

4. The lubricant oil film shear force detection device according to claim 1 or 3, characterized in that: The supporting device (2) includes a servo electric cylinder 2 (11) and a screw lifting platform (12), the screw lifting platform (12) includes a lifting platform body, a movable support plate and a plurality of hinges, one end of the movable connecting plate is hinged to one end of the upper end surface of the fixed support plate at the top of the lifting platform body through a hinge, the servo electric cylinder 2 (11) is tilted and arranged between the fixed support plate and the movable connecting plate, the bottom of the servo electric cylinder 2 (11) is hinged to the other end of the upper end surface of the fixed support plate through a hinge, and the protruding end of the servo electric cylinder 2 (11) is hinged to the lower end surface of the movable connecting plate through a hinge.

5. The lubricant oil film shear force detection device according to claim 4, characterized in that: The ball drive mechanism includes an electric spindle 2 (9), an electric spindle fixing part 2 (10), a transmission spindle 2 (8) and a bracket 2 (16). The electric spindle fixing part 2 (10) is fixedly connected to the upper end surface of the screw lifting platform (12). The electric spindle 2 (9) is installed above the electric spindle fixing part 2 (10). One end of the transmission spindle 2 (8) is coaxially fixedly connected to the electric spindle 2 (9). The other end of the transmission spindle 2 (8) is fixedly connected to the ball test piece (13). The upper end of the bracket 2 (16) is coaxially matched with the transmission spindle 2 (8). The lower end of the bracket 2 (16) is installed on the table of the bench mechanical structure (1).

6. The lubricant oil film shear force detection device according to claim 5, characterized in that: It also includes a data acquisition, monitoring and storage system, which includes a pressure sensor 1, a pressure sensor 2, a speed sensor 1, a speed sensor 2, a temperature sensor 1, a temperature sensor 2 and a torque sensor. The pressure sensor 1 and the pressure sensor 2 are respectively installed between the servo electric cylinder 1 (17) and the damping adjustment device (19) and on the side of the electric spindle 1 (5), and are used to measure the load applied by the servo electric cylinder 1 (17) and the oil film shear force; the temperature sensor 1 and the temperature sensor 2 are respectively installed on the lubricating oil inlet pipe and The ring test piece (14) is used to measure the lubricating oil supply temperature and the temperature of the contact area between the ball and the ring friction pair test piece (23); the speed sensor 1 and the speed sensor 2 are respectively installed on the axial surface of the electric spindle 1 (5) and the electric spindle 2 (9), and are respectively used to monitor the speed of the electric spindle 1 (5) and the electric spindle 2 (9) in real time; one end of the torque sensor is fixedly connected to the axial end of the electric spindle 2 (9), and the other end of the torque sensor is fixedly connected to the transmission spindle 2 (8), and is used to measure the oil film shear force in the contact area between the ball and the ring friction pair test piece (23).

7. The lubricant oil film shear force detection device according to claim 1 or 6, characterized in that: It also includes a circulating lubrication system, which includes an oil tank, a nozzle, an oil supply pipeline, an oil return pipeline and two oil pumps. The oil tank is located directly below the sample cavity and is installed on the lower end surface of the table of the bench mechanical structure (1). The sample cavity is a rectangular box body, which is installed on the table of the bench mechanical structure (1). A transmission main shaft mounting hole 1 that is clearance-matched with the transmission main shaft 1 (7) is opened on the box wall on one side of the sample cavity. The transmission main shaft mounting hole 1 is a circular hole. The end of the transmission main shaft 1 (7) coaxially passes through the transmission main shaft mounting hole 1 and is coaxially fixedly connected to the ring test piece (14). The sample cavity A second transmission main shaft mounting hole which is clearance-matched with the second transmission main shaft (8) is provided on the box wall on the other side of the body. The second transmission main shaft mounting hole is a long strip hole with the long axis of the long strip hole arranged in the vertical direction. The end of the second transmission main shaft (8) passes through the second transmission main shaft mounting hole and is fixedly connected to the ball test piece (13). A nozzle is installed on the side wall of the sample cavity. The nozzle head of the nozzle faces the contact area of the ball and ring friction pair test piece (23). The oil inlet of the nozzle is connected to the oil outlet of the oil tank through the oil supply pipeline. The oil outlet at the bottom of the sample cavity is connected to the oil inlet of the oil tank through the oil return pipeline. Oil pumps are installed on both the oil supply pipeline and the oil return pipeline.

8. A dual measurement method for oil film shear force, characterized by: The dual measurement method of oil film shear force is implemented based on the lubricant oil film shear force detection device according to claim 7, and is characterized in that: the method is implemented by the following steps: Step 1: Adjust the posture of the ball specimen (13): When measuring, the height of the lead screw lifting platform (12) is adjusted to adjust the height of the electric spindle 2 (9), and the posture of the ball test piece (13) is adjusted by the servo electric cylinder 2 (11), thereby simulating the contact state between the ball and the ring under different rotation angles of the ball in the angular contact ball bearing; Step 2: Formation of oil film: The oil pump is started to spray the lubricating oil in the oil tank through the nozzle to the contact area of the ball and ring friction pair test piece (23), thereby forming an oil film; Step 3: Adjust the contact area between the ball and the ring: Start the electric spindle 1 (5) and the electric spindle 2 (9) and adjust their rotation speeds so that the contact area of the ball and the ring friction pair test piece (23) is in a pure rolling state, and at the same time start the industrial water cooler to dissipate heat from the electric spindle 1 (5) and the electric spindle 2 (9); Step 4: Apply load to the contact area between the ball and the ring: Drive the servo electric cylinder (17) and turn on the air pump to supply air to the air bearing (21) to complete the support of the electric spindle (5), and apply a load to the contact area of the ball and ring friction pair test piece (23) by adjusting the weight of the weight plate to ensure that the electric spindle (5) does not generate an overturning moment; Step 5: Generate elastohydrodynamic oil film shear force: Under the conditions of a certain load and rotation speed and sufficient lubrication, an elastohydrodynamic oil film with a certain thickness can be formed between the ball specimen (13) and the ferrule specimen (14). By adjusting the rotation speeds of the electric spindle 1 (5) and the electric spindle 2 (9), the linear speeds of the contact points of the ball specimen (13) and the ferrule specimen (14) are different, thereby forming a certain sliding speed difference, so that a corresponding elastohydrodynamic oil film shear force can be generated on the contact surface. Step 6: Measure the oil film shear force: Under the action of the oil film shear force, the air bearing (21) deflects. At this time, the pressure sensor 2 at the same height as the oil film shear force can display the value of the oil film shear force. At the same time, the torque generated by the oil film shear force can also be measured by the torque sensor installed on the second transmission main shaft (8), thereby realizing dual measurement of the oil film shear force.

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