Ball screw nut pair transmission power and efficiency testing device and testing method

Abstract

The present application relates to the field of ball screw nut pair transmission power and efficiency test, and relates to a ball screw nut pair transmission power and efficiency testing device and testing method. The ball screw nut pair transmission power and efficiency testing device comprises a loading screw driving device, a load loading device, a load transmission device, a measured nut clamping device, a measured screw driving device, a torque measurement and transmission device and a displacement measurement device. The loading screw driving device is connected with the load loading device. The load loading device is connected with the load transmission device. The load transmission device comprises a first spherical hinge floating joint, a second spherical hinge floating joint, a floating joint connector, a floating joint connecting seat and a pressure sensor. The pressure sensor is connected with the measured nut clamping device. The measured screw driving device is connected with the measured screw through the torque measurement and transmission device. The measured screw is matched with the measured nut. The displacement measurement device is used for measuring the displacement of the measured nut clamping device.

Description

Technical Field

[0001] This invention relates to the field of testing the transmission power and efficiency of ball screw nut pairs, and specifically to a testing device and method for testing the transmission power and efficiency of ball screw nut pairs. Background Technology

[0002] As a core transmission component that converts rotary motion into linear motion, the transmission efficiency and power characteristics of ball screw nut assemblies are key indicators for measuring their performance, predicting their lifespan, and even assessing the energy consumption of the entire equipment system. Therefore, developing high-precision dedicated testing devices and methods is an important requirement in the manufacturing industry, especially in the field of high-end equipment.

[0003] Currently, there are several testing devices and methods for testing the power and efficiency of ball screw nut pairs. Patent publication number CN110542501A discloses a ball screw transmission efficiency testing system, employing a vertical structure. The screw under test rotates, and the nut moves linearly, compressing multiple spring-force sensor assemblies evenly distributed circumferentially below. By measuring the total axial force and input torque, the average efficiency of the screw over a certain stroke is calculated. This linear efficiency measurement concept is advanced and offers high accuracy, making it particularly suitable for high-load, static efficiency testing. However, it suffers from poor load adjustability and controllability; changing the load requires replacing spring sets with different stiffnesses, making dynamic, stepless load changes during testing impossible. The entire system is a closed shell structure, with the screw under test supported inside. Installation and replacement require opening the top cover and operating components such as the bearing housing, making the process complex. With limited compensation capacity, the nut bracket slides in the guide groove of the housing through the lugs, which is a rigid guide. Although multiple sets of springs connected in parallel can share the load equally, if the initial coaxiality deviation is large, it will generate additional bending moment in the lead screw and nut pair, affecting the test accuracy and the life of the parts.

[0004] Patent CN111060311A discloses an improved ball screw efficiency testing fixture. It uses a spring loading device to provide axial force and incorporates a polyurethane self-aligning rod between the loading rod and the nut under test, achieving flexible loading. This allows for adaptive absorption of radial and angular deviations, reducing the requirements for machining and assembly precision. The flexible self-aligning design ensures that the load is transmitted along the axis to the test piece after adaptive adjustment by the self-aligning rod, effectively protecting the test piece and improving measurement accuracy. However, the long-term stability and creep of the polyurethane material need to be considered. Furthermore, the load application method remains passive, with the load magnitude set by the spring preload. Changing the load requires replacing spring sets with different stiffnesses, resulting in poor dynamic adjustment capability.

[0005] Patent publication number CN107576496A discloses an efficiency testing device for ball screw pairs. This device employs a vertical structure, with an upper servo motor driving the screw under test to rotate via a torque sensor. A lower servo motor pushes a placement mechanism for the nut under test upwards via a ball screw pair, applying an axial load. Force is indirectly generated by controlling the displacement of the lower servo motor. The accuracy of force control depends on the transmission accuracy of the lower screw pair and the system rigidity. While this improves force control accuracy to some extent, it lacks closed-loop control, resulting in limited accuracy and response speed. Furthermore, its compensation capability is weak, relying solely on springs and washers in the linkage mechanism to provide very limited radial flexibility. The main components remain rigidly connected, requiring high coaxiality during installation.

[0006] The main problems with existing ball screw transmission efficiency and power testing devices and methods are as follows:

[0007] (1) The load control capability is insufficient, and it is impossible to achieve precise control and real-time adjustment of the load. The optimization of the force transmission path is ignored when actively controlling the load.

[0008] (2) The error compensation mechanism is insufficient. The rigid connection method is prone to additional bending moment due to installation error, which leads to non-concentricity of force axis and affects the test accuracy.

[0009] (3) The equipment has a complex structure, the installation and replacement process of the test parts is cumbersome, the testing efficiency is low, and it is difficult to meet the needs of rapid batch testing.

[0010] Therefore, there is an urgent need for a new type of testing device and method that can integrate precise control of dynamic load, effective automatic compensation for centering error, and rapid replacement of the test piece, so as to achieve highly reliable and efficient testing of the transmission efficiency and power of ball screw nut pairs. Summary of the Invention

[0011] To address the technical problems existing in the prior art, this invention provides a testing device and method for testing the transmission power and efficiency of a ball screw nut pair.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] In a first aspect, a ball screw nut pair transmission power and efficiency testing device includes a loading screw drive device, a load loading device, a load transmission device, a nut clamping device, a screw drive device, a torque measurement and transmission device, and a displacement measurement device.

[0014] The loading screw drive device is connected to the load loading device; the load loading device is connected to the load transmission device.

[0015] The load transfer device includes a first ball-joint floating joint, a second ball-joint floating joint, a floating joint connector, a floating joint connector base, and a pressure sensor. One end of the first ball-joint floating joint is fixed to a loading nut via a loading bracket. The other end of the first ball-joint floating joint is connected to the second ball-joint floating joint via the floating joint connector. The threads of the first and second ball-joint floating joints are opposite in direction. The second ball-joint floating joint is fixed to the floating joint connector base. The floating joint connector base is connected to one end of the pressure sensor, and the pressure sensor is connected to the nut clamping device to be tested.

[0016] The aforementioned nut clamping device is used to fix the nut to be tested;

[0017] The test lead screw drive device is connected to the test lead screw through a torque measurement and transmission device, and the test lead screw is engaged with the test nut;

[0018] The displacement measuring device is used to measure the displacement of the nut clamping device under test;

[0019] As a further technical solution, the load loading device includes a loading screw and a loading nut; the loading screw and the loading nut are threaded together, the loading nut is fixed on the first guide rail slider group, and the first guide rail slider group is engaged with the guide rail; the loading screw is connected to a loading screw drive device.

[0020] As a further technical solution, the nut clamping device includes a nut clamping frame, a nut clamping block, and a clamping device top plate; the nut clamping frame is fixed to the clamping device top plate, and the clamping device top plate is fixed to the second guide rail slider assembly, which cooperates with the guide rail to restrict the rotation of the nut; the nut clamping frame is fixed to the nut clamping block, which has a hollow structure, with square grooves adapted to the size of the nut on its first and second end faces, and stepped short cylindrical shafts on both end faces of the nut.

[0021] As a further technical solution, the test ball screw drive device includes a test ball screw drive servo motor and a drive motor fixing base; the test ball screw drive servo motor and the drive motor fixing base are locked together; the motor shaft of the test ball screw drive servo motor is connected to a torque measurement and transmission device through a third coupling, outputting drive torque, and the torque is transmitted to the external hexagonal transmission shaft through the torque measurement and transmission device, causing it to rotate, thereby driving the test ball screw nut pair to move.

[0022] As a further technical solution, the torque measurement and transmission device includes a second coupling, a third coupling, a torque sensor, and an external hexagonal transmission shaft; the first shaft of the torque sensor is connected to the motor shaft of the ball screw drive servo motor under test through the third coupling, and the second shaft of the torque sensor is connected to the second end of the external hexagonal transmission shaft fixed in the transmission shaft fixing seat through the second coupling, so as to realize torque transmission and accurately measure the driving torque of the ball screw nut pair under test.

[0023] As a further technical solution, the first end of the lead screw to be tested is provided with an internal hexagonal hole, which is connected to the external hexagonal column on the external hexagonal transmission shaft to transmit rotational motion. The second end of the lead screw to be tested is installed in the lead screw support device. The lead screw to be tested is positioned by the dovetail groove slider of the lead screw support device cooperating with the dovetail groove base on the base.

[0024] As a further technical solution, the displacement measuring device is a laser displacement sensor, which is installed on one side of the nut clamping device to be tested. The laser displacement sensor directly measures the displacement of the nut clamping device to be tested, and is not affected by mechanical factors such as lead screw backlash, elastic deformation, thermal expansion, and manufacturing errors. It reflects the true motion state of the nut under loading conditions. The health status of the transmission system can be monitored in real time by comparing the true displacement measured by the laser sensor with the theoretical displacement calculated by the torque sensor speed.

[0025] As a further technical solution, it also includes a first limiting device and a second limiting device, wherein the first limiting device is used to limit the safe position of the load loading device; and the second limiting device is used to limit the safe position of the nut clamping device to be tested.

[0026] Secondly, based on the aforementioned ball screw nut pair transmission power and efficiency testing device, the present invention also provides a testing method.

[0027] The lead screw drive device under test, as the main drive end of the system, is responsible for generating and controlling the rotational motion of the lead screw under test, simulating the input conditions during actual operation.

[0028] The rotational motion of the lead screw under test is converted into linear motion by the nut under test, driving the nut clamping device to move along the guide rail;

[0029] The load loading device is responsible for applying a precise and controllable axial load to the nut under test;

[0030] Receive the force signal detected by the pressure sensor F actual and compare it with the target value F target Compare and calculate the force error. e = F target -F actual ;

[0031] Based on the error, proportional, integral, and differential operations are performed to generate a corrected torque command. T cmd Torque command T cmd The torque is sent to the loading screw drive; the loading screw drive precisely outputs the corresponding torque, which is converted into a linear force by the loading ball screw nut pair, and then applied to the nut under test through the load transmission device; the above process cycles at a frequency of several kilohertz, forming a dynamic balance system, thus... F actual Capable of fast and stable tracking F target ;

[0032] Then the torque measuring and transmission device directly measures the input torque. T in and the speed of the lead screw to be measured n Pressure sensor directly measures F actual The displacement measuring device directly measures the moving speed of the nut clamping device under test. V Simultaneously collect data from all sensors and perform real-time calculation of effective power. P 2 and transmission efficiency η .

[0033] As a further technical solution, the effective power P The calculation method for 2 is as follows:

[0034]

[0035] As a further technical solution, the transmission efficiency η The calculation method is as follows:

[0036]

[0037] in, P The lead of the lead screw to be tested is given.

[0038] The beneficial effects of this invention are as follows:

[0039] This invention enables the testing of the transmission power and efficiency of ball screw nut pairs, achieving high-precision, dynamically adjustable load loading. It abandons traditional passive spring loading or open-loop servo control modes, employing a real-time force closed-loop control strategy based on pressure sensor feedback. This allows the system to not only accurately maintain a constant load but also to programmatically load complex dynamic load spectra. This software-defined load capability greatly expands the testing scenarios, enabling more realistic simulation of actual working conditions for fatigue testing and dynamic performance evaluation. Furthermore, this invention introduces a load transfer device into the load transfer path. This device uses a double-ball-joint floating joint and a finely adjustable length connection structure, allowing for minor radial and angular deviations between the loading end and the test end. Through the adaptive rotation of the ball joint, it ensures that the axial loading force is always transmitted along the axis of the ball screw under test. This solves the problem of force axis misalignment caused by machining, assembly errors, or guide rail wear, avoids interference from additional bending moments on the test results, improves the accuracy and reliability of the measurement, and simultaneously reduces the stringent requirements for the machining and assembly precision of the equipment foundation. This invention uses a displacement measuring device to directly measure the actual displacement of the nut under test, rather than relying on the theoretical lead and rotational speed of the lead screw for indirect calculation. This eliminates speed measurement errors caused by factors such as lead screw backlash, elastic deformation, and manufacturing errors, making the calculation of output power more accurate.

[0040] This invention features a highly efficient quick-change mechanism. The test screw pair is positioned by a dovetail groove slider on the test screw support seat engaging with a dovetail groove base on the base, and is driven via a simple external hexagonal shaft / internal hexagonal hole connection. When changing the test component, simply loosen the clamping block and insert / remove the limiting pin; the entire pre-assembled test unit, including the screw pair and support seat, can then slide out / in along the groove. This modular component changeover design shortens auxiliary time, improves the efficiency of batch testing, and is suitable for large-scale quality inspection and performance screening of the same product model. Attached Figure Description

[0041] Figure 1 This is an assembly drawing of the overall structure of the ball screw nut pair transmission power and efficiency testing device.

[0042] Figure 2 This is a schematic diagram of the guide rail and base layout;

[0043] Figure 3 A schematic diagram of the load loading device after removing the top plate.

[0044] Figure 4 This is a schematic diagram of the load transfer device.

[0045] Figure 5 This is a schematic diagram of the structure of the nut clamping device to be tested;

[0046] Figure 6A schematic diagram showing the installation method of a ball screw nut assembly;

[0047] Figure 7 A schematic diagram of the structure of the lead screw support device;

[0048] Figure 8 This is a schematic diagram of the support device for the lead screw under test.

[0049] Figure 9 This is a schematic diagram of the displacement measuring device.

[0050] Figure 10 This is a schematic diagram of the limiting device.

[0051] In the diagram: 1. Loading servo motor; 2. Loading motor mounting base; 3. Loading screw mounting base; 4. Loading device top plate; 5. Loading screw support device; 6. Load transmission device; 7. Clamping device top plate; 8. Nut to be tested; 9. Lead screw to be tested; 10. External hexagonal transmission shaft; 11. Displacement measuring device; 12. Base; 13. First coupling; 14. Guide rail; 15. Guide rail base; 16. Nut clamping device; 17. Transmission shaft mounting base. 18. Fixed base; 19. Second coupling; 20. Torque sensor; 21. Third coupling; 22. Drive motor fixed base; 23. Servo motor for driving the lead screw under test; 24. Loading lead screw; 25. First limiting device; 26. Nut seat; 27. Loading nut; 28. Loading frame fixed plate; 29. ​​Loading frame; 30. Second limiting device; 31. Support device for the lead screw under test; 32. First guide rail slider group; 33. Second guide rail slider group; 44. Locking screw 34. Limit switch; 35. Limit switch bracket; 51. Loading screw support seat; 52. Loading screw support seat bearing; 53. Loading screw support seat bearing retaining ring; 54. Loading screw support seat base; 61. First ball joint floating joint; 62. Floating joint connector; 63. Second ball joint floating joint; 64. Floating joint connector seat; 65. Pressure sensor; 66. Washer; 67. Locking bolt; 81. Vertical support column; 82. Orthogonal 83. Column fixing clamp; 84. Open column fixing bracket; 85. Horizontal column; 86. Sensor mounting plate; 87. Laser displacement sensor; 88. Column fixing base; 161. Nut clamping bracket; 162. Nut clamping block; 301. Lead screw support seat; 302. Lead screw support seat bearing; 303. Lead screw support seat bearing retaining ring; 304. Lead screw support seat dovetail groove slider; 305. Lead screw support seat dovetail groove base; Detailed Implementation

[0052] To address the shortcomings of existing technologies, the purpose of this invention is to provide a testing device and method for testing the transmission power and efficiency of ball screw nut pairs.

[0053] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0054] This embodiment provides a ball screw nut pair transmission power and efficiency testing device, including a loading screw drive device, a load loading device, a load transmission device, a nut clamping device, a torque measurement and transmission device, a ball screw drive device, a displacement measurement device, a first limit device, and a second limit device.

[0055] The loading screw drive device is mounted on the base and connected to the first end of the loading screw via a first coupling; the load loading device is mounted on the first guide rail slider assembly and connected to the nut clamping device under test via a load transmission device, applying axial load to the nut under test along the axis of the nut pair under test; the driving device of the screw under test is connected to the first end of the screw under test via a torque measuring and transmission device; the displacement measuring device measures the displacement of the nut clamping device under test; the first limiting device ensures the load loading device is in a safe position; the second limiting device ensures the nut clamping device under test is in a safe position.

[0056] In a typical embodiment of the present invention, such as Figure 1 , Figure 2 As shown, this embodiment provides a ball screw nut pair transmission power and efficiency testing device, mainly including a load loading servo motor 1, a loading motor fixing base 2, a loading screw fixing base 3, a loading device top plate 4, a loading screw support device 5, a load transmission device 6, a clamping device top plate 7, a nut to be tested 8, a screw to be tested 9, an external hexagonal transmission shaft 10, a displacement measuring device 11, a base 12, a first coupling 13, a guide rail 14, a guide rail base 15, a nut to be tested clamping device 16, a transmission shaft fixing base 17, a second coupling 18, a torque sensor 19, a third coupling 20, a drive motor fixing base 21, a screw to be tested drive servo motor 22, a loading screw 23, a first limiting device 24, a nut seat 25, a loading nut 26, a loading frame fixing plate 27, a loading frame 28, a second limiting device 29, a screw to be tested support device 30, a first guide rail slider group 31, and a second guide rail slider group 32.

[0057] The schematic diagram of the guide rail and base arrangement in this embodiment is as follows: Figure 2 As shown. The base 12 is bolted with the following components in sequence: loading motor mounting base 2, loading screw mounting base 3, loading screw support device 5, guide rail base 15, test screw support device 30, transmission shaft mounting base 17, torque sensor 19, and drive motor mounting base 21.

[0058] The guide rail base 15 is symmetrically fixed to the base 12 by bolts, and the guide rail 14 is symmetrically fixed to the guide rail base 15 by screws. The first guide rail slider group 31 and the second guide rail slider group 32 are installed on the guide rail 14. A load loading device is fixed on the first guide rail slider group 31, and the load loading device can move on the guide rail 14 with the first guide rail slider group 31. A nut clamping device 16 to be tested is fixed on the second guide rail slider group 32, and the nut clamping device 16 to be tested can move on the guide rail 14 with the second guide rail slider group 32.

[0059] As a further technical solution, the load loading device, such as Figure 1 , Figure 2 , Figure 3 As shown, the device includes a loading screw 23, a loading nut 26, a nut seat 25, a loading frame 28, a loading frame fixing plate 27, and a loading device top plate 4. The loading nut 26 is a standard ball screw nut with a through hole on its first end face. The nut seat 25 is a nut seat made to match the loading nut 26, with a threaded hole on its first end face. The loading frame fixing plate 27 has a through hole. A screw passes through the first end face of the loading frame 28, through the through hole of the loading nut 26, and then screws into the threaded hole of the nut seat 25, thus connecting the loading nut 26 and the loading nut seat. The female seat 25 and the loading frame fixing plate 27 are locked together. In addition, the loading frame fixing plate 27 is provided with a mounting through hole for the loading frame 28. The first end face of the loading frame 28 is provided with a threaded hole. After the screw passes through the second end face of the loading frame fixing plate 27, it is screwed into the threaded hole on the first end face of the loading frame 28. In addition, the top end face of the nut seat 25 is provided with a threaded hole. The nut seat 25 is locked to the loading device top plate 4 by screws. In addition, the loading device top plate 4 is mounted on the first guide rail slider group 31 by screws to restrict the rotation of the loading nut 26.

[0060] As a further technical solution, the loading screw drive device includes a load loading servo motor 1 and a loading motor fixing base 2; the load loading servo motor 1 is locked to the loading motor fixing base 2 by bolts; the motor shaft of the load loading servo motor 1 is connected to the first end of the loading screw 23 fixed to the loading screw fixing base 3 through a first coupling 13, and the second end of the loading screw 23 is fixed in the loading screw support device 5; the structural schematic diagram of the loading screw support device 5 is shown below. Figure 7As shown, the system includes a loading screw support seat 51, a loading screw support seat bearing 52, a loading screw support seat bearing retaining ring 53, and a loading screw support seat base 54. The loading screw support seat bearing 52 and the loading screw support seat bearing retaining ring 53 are installed in the loading screw support seat 54 to be tested. The second end of the loading screw 23 is installed in the loading screw support seat bearing 52. The loading screw support seat 54 is locked to the loading screw support seat base 54 by screws. The loading screw drive device converts the rotational motion of the loading screw 23 into the linear motion of the load loading device, and applies the load to the load transmission device 6 through the loading frame 28 of the load loading device.

[0061] As a further technical solution, the structural schematic diagram of the load transfer device 6 is shown below. Figure 4As shown, the system includes a first ball-joint floating joint 61, a second ball-joint floating joint 62, a floating joint connector 63, a floating joint connector seat 64, a pressure sensor 65, a washer 66, and a locking bolt 67. The first ball-joint floating joint 61 is equipped with a countersunk hole, and the loading frame 28 of the load loading device is equipped with a threaded hole. The first ball-joint floating joint 61 and the loading frame 28 of the load loading device are locked together by screws. Both the first ball-joint floating joint 61 and the second ball-joint floating joint 63 have threaded rods. The floating joint connector 62 has threaded holes at both ends. The first ball-joint floating joint 61 and the first end of the floating joint connector 62 are connected by threads, and the second ball-joint floating joint 63 and the second end of the floating joint connector 62 are connected by threads. Furthermore, the threads on the first ball-joint floating joint 61 and the second ball-joint floating joint 63 have opposite directions of rotation, and the floating joint connector 62... The internal threads on both sides are designed to correspond, and the positive distance between the first ball-joint floating joint 61 and the second ball-joint floating joint 63 can be adjusted by rotating the floating joint connector 62 to compensate for machining and assembly errors. The second ball-joint floating joint 63 is equipped with a countersunk hole, and the floating joint connector 64 is equipped with a threaded hole. The second ball-joint floating joint 63 and the floating joint connector 64 are locked together by screws. The floating joint connector 64 is equipped with a threaded rod, and the first end of the pressure sensor 65 is equipped with a threaded hole. The floating joint connector 64 and the pressure sensor 65 are locked together by a threaded connection. The second end of the pressure sensor 65 is equipped with a threaded hole. The nut clamping device 16 is equipped with a through hole. The locking bolt 67 passes through the through hole on the force transmission frame of the nut clamping device, passes through the washer 66, and is screwed into the threaded hole at the second end of the pressure sensor 65 to lock the pressure sensor 65 and the nut clamping device 16 together. This invention specifically addresses the coaxiality issue. The load transfer device 6 employs a ball-joint floating joint, a flexible element that can adaptively absorb radial and angular deviations. This reduces the stringent requirements for equipment machining and assembly precision. The flexible self-aligning design ensures that the load, after adaptive adjustment by the ball-joint floating joint, is effectively transferred along the axis to the workpiece under test, preventing the applied force from easily deviating from the axis due to centering errors and reducing measurement errors caused by bending moments. Furthermore, the threaded rods on the first ball-joint floating joint 61 and the second ball-joint floating joint 63 have opposite thread directions, and the internal threads on both sides of the floating joint connector 62 are designed accordingly. This ensures that when the floating joint connector 62 rotates in one direction, the first ball-joint floating joint 61 and the second ball-joint floating joint 63 move closer together, and when the floating joint connector 62 rotates in the other direction, the first ball-joint floating joint 61 and the second ball-joint floating joint 63 move further apart. This achieves a precise, reliable, compact, and easily implemented linear length fine-tuning function, compensating for machining and assembly errors.

[0062] As a further technical solution, the structural schematic diagram of the nut clamping device 16 to be tested is shown below. Figure 5 , Figure 6 As shown, the device includes a nut clamping frame 161, a nut clamping block 162, and a clamping device top plate 4. The nut clamping frame 161 is equipped with a threaded hole. The clamping device top plate 4 is locked to the nut clamping frame 161 by screws. The clamping device top plate 4 is also mounted on the second guide rail slider assembly 32 by screws to restrict the rotation of the nut 8 under test. The nut clamping frame 161 is equipped with a threaded hole, and the nut clamping block 162 is equipped with a through hole and has a hollow structure. Its first and second end faces are provided with fittings for the nut 8 under test. The test nut 8 has a square groove of size 8. Stepped short cylindrical shafts are fitted on both end faces of the nut to be tested. The test nut clamping bracket 161 and the test nut clamping block 162 are locked together with bolts to fix the test nut 8. The load is transmitted to the test nut clamping device 16 through the load transmission device 6, and then to the test nut 8 through the test nut clamping block 162, realizing the axial loading of the ball screw nut pair under test. The test screw 9 mates with the test nut 8. The first end of the test screw 9 has an internal hexagonal hole, and an external hexagonal prism is fitted on the external hexagonal transmission shaft 10. Figure 5 The external hexagonal transmission shaft 10 shown is connected to the internal hexagonal hole at the first end of the lead screw 9 under test through an external hexagonal column, transmitting rotational motion.

[0063] The second end of the lead screw 9 to be tested is installed in the lead screw support device 30, and the structural schematic diagram of the lead screw support device is shown below. Figure 8 As shown, the system includes a lead screw support base 301, a lead screw support base bearing 302, a lead screw support base bearing retaining ring 303, a lead screw support base dovetail groove slider 304, and a lead screw support base dovetail groove base 305. The lead screw support base bearing 302 and the lead screw support base bearing retaining ring 303 are installed in the lead screw support base 301, and the second end of the lead screw 9 is installed in the lead screw support base bearing 302. The support 301 is locked to the dovetail groove slider 304 of the lead screw support seat by screws, and the dovetail groove base 305 of the lead screw support seat is locked to the base 12 by screws; the dovetail groove slider 304 and the dovetail groove base 305 of the lead screw support seat are engaged by dovetail grooves, and the dovetail groove slider 304 and the dovetail groove base 305 of the lead screw support seat are provided with limit pin holes, and the relative sliding between the two is restricted by the limit pins.

[0064] As a further technical solution, the test ball screw drive device includes a test ball screw drive servo motor 22 and a drive motor fixing base 21; the test ball screw drive servo motor 22 is locked to the drive motor fixing base 21 by bolts; the motor shaft of the test ball screw drive servo motor 22 is connected to the torque measurement and transmission device through a third coupling 20, outputting drive torque, and the torque is transmitted to the external hexagonal transmission shaft 10 through the torque measurement and transmission device, so that it generates rotational motion, thereby driving the test ball screw nut pair to move.

[0065] As a further technical solution, the torque measurement and transmission device includes a second coupling 18, a third coupling 20, a torque sensor 19, and an external hexagonal transmission shaft 10. The first shaft of the torque sensor 19 is connected to the motor shaft of the ball screw drive servo motor 22 under test through the third coupling 20, and the second shaft of the torque sensor 19 is connected to the second end of the external hexagonal transmission shaft 10, which is fixed in the transmission shaft fixing seat 17, through the second coupling 18, so as to realize torque transmission and accurately measure the driving torque of the ball screw nut pair under test.

[0066] As a further technical solution, the displacement measuring device 8 is as follows: Figure 9 As shown, the system includes a vertical support column 81, an orthogonal support column fixing clamp 82, an open support column fixing bracket 83, a horizontal support column 84, a sensor mounting plate 85, a laser displacement sensor 86, and a support column fixing base 87. The support column fixing base 87 is fixed to the base 12 with screws. The vertical support column 81 is installed in the vertical hole of the support column fixing base 87 and locked to the support column fixing base 87 with screws. One fixing hole of the orthogonal support column fixing clamp 82 is coaxial with the vertical support column 81, and the vertical support column 81 is fixed to the orthogonal support column with screws. The clamp 82 is locked in place; the horizontal support 84 is installed in another fixing hole of the orthogonal support fixing clamp 82, orthogonal to the vertical support 81, and the horizontal support 84 is locked to the orthogonal support fixing clamp 82 by screws; the open support fixing bracket 83 is installed on the horizontal support 84, and the open support fixing bracket 83 is locked to the horizontal support 84 by screws. The tail end of the open support fixing bracket 83 has a threaded hole, and the sensor mounting plate 85 is fixed to the open support fixing bracket 83 by screws, and the laser displacement sensor 86 is fixed to the sensor mounting plate 85 by screws. The laser displacement sensor 86 directly measures the displacement of the nut clamping device under test, and is not affected by mechanical factors such as screw backlash, elastic deformation, thermal expansion, and manufacturing errors. It reflects the true motion state of the nut under loading conditions. The health status of the transmission system can be monitored in real time by comparing the true displacement measured by the laser sensor 86 with the theoretical displacement calculated by the torque sensor 19.

[0067] As a further technical solution, the structural schematic diagram of the first limiting device 24 and the second limiting device 29 is as follows: Figure 10 As shown, the device includes a locking nut 33, a limit switch 34, and a limit switch bracket 35. The first limit device 24 is used to limit the safe position of the load loading device. The second limit device 29 is used to limit the safe position of the nut clamping device 16 to be tested. The first limit device 24 and the second limit device 29 are mounted on the base 12 with screws. The limit switches 24 in the first limit device 24 and the second limit device 29 are both fixed to the limit switch bracket 35 with locking nuts 33. The relative position of the limit switch 34 and the limit switch bracket 35 can be adjusted by adjusting the locking nuts 33 to meet the limit requirements. The bottom of the limit switch bracket 35 has an elongated hole, which can be used to finely adjust the position of the first limit device 24 and the second limit device 29 to adapt to the requirements of limiting different safe positions.

[0068] Secondly, based on the aforementioned ball screw nut pair transmission power and efficiency testing device, the present invention also provides a testing method.

[0069] The servo motor 22 driving the lead screw 9 under test, the torque sensor 20, the lead screw and nut pair under test, and the nut clamping device 16 serve as the main drive end of the system, responsible for generating and controlling the rotational motion of the lead screw 9 under test, simulating the input conditions during actual operation. The rotational motion of the lead screw 9 under test is converted into linear motion by the nut 8 under test, driving the nut clamping device 16 to move along the guide rail. The load loading servo motor 1, the load loading lead screw and nut pair, the load loading device, and the load transmission device 6 serve as the driven loading end of the system, responsible for applying a precise and controllable axial load to the nut 8 under test. They do not actively control the motion, but rather use force closed-loop control to ensure that the output force accurately tracks the set value.

[0070] The controller receives the force signal from the pressure sensor. F actual and compare it with the target value F target Compare and calculate the force error. e = F target - F actual The controller performs proportional, integral, and derivative calculations based on the error to generate a corrected torque command. T cmd Torque command T cmd The load is sent to the driver of the load-loading servo motor 1. The load-loading servo motor 1 precisely outputs the corresponding torque, which is converted into linear force by the load-loading ball screw nut pair, and then applied to the nut 8 under test through the load transmission device 6. The above process runs cyclically at a frequency of several kilohertz, forming a dynamic balance system, so that... F actual Capable of fast and stable trackingF target In this way, not only can a fixed value be set... F target It also allows the controller to set a dynamic target signal that changes over time. F target ( t ), such as sine waves, ramp waves and square waves, and can even import force data enveloping data collected under real working conditions.

[0071] The testing method employed in this invention enables high-precision closed-loop control of both constant axial loads and dynamic loads, and the applied load is adjustable in real time, allowing for loading tests of various constant and dynamic loads without machine downtime. Regardless of the speed at which the nut under test moves, the actual force detected by the pressure sensor remains constant. F actual Quickly and stably follow the user-defined target force F target .

[0072] Specific implementation and testing process:

[0073] When testing the transmission efficiency and power of a ball screw nut pair, the controller first adjusts the nut 8 to its initial position. This initial position can be set via a host computer, where test parameters, including target speed and target load, are also set. F target or F target ( t The test is controlled by a controller during the testing process. Then, the test begins. The controller sends a command to the driver of the lead screw drive servo motor 22, causing the lead screw drive servo motor 88 to start rotating at a set speed. This drives the nut 8 under test and the nut clamping device 16 to move linearly, thereby pushing the pressure sensor 65. The pressure sensor 65 produces a slight deformation, which is detected and immediately outputs a force signal. F actual Then, it enters the closed-loop control adjustment phase. The adjustment process is instantaneous and continuous, ultimately bringing the system into dynamic equilibrium and stabilizing the force at a certain level. F target or F target ( t Within a very small error range near the target. Then, the test stroke for the transmission efficiency and power of the ball screw nut pair under test is entered, and the torque sensor 19 directly measures the input torque. T in and the speed of the lead screw to be measured n Pressure sensor 65 directly measures F actualThe laser displacement sensor 86 directly measures the moving speed of the nut clamping device 16. V The controller synchronously collects data from all sensors and performs real-time calculations of the effective power. P 2 and transmission efficiency η .

[0074]

[0075] The effective power of the ball screw nut pair under test was measured. P When calculating 2, the following formula (1) is used: the moving speed of the nut clamping device 16 to be tested is directly measured by the laser displacement sensor 86. V This allows it to be directly measured by pressure sensor 65. F actual Multiply to accurately calculate effective power P 2. And systematically change the rotational speed of the lead screw 9 under test. n For each data point, calculate the effective power. P 2.

[0076] In terms of transmission efficiency η The calculation is performed according to the following formula (2), and the transmission efficiency is calculated. η For effective power P 2 and input power P The ratio of 1 to the input power at this point P 1 is a torque sensor 19 that directly measures the input torque. T in and the speed of the lead screw under test 9 n Multiply, at this point the effective power P 2. The rotational speed of the lead screw under test can be 9. n Force signal F actual and the lead of the lead screw under test 9 P The product of these three factors is used for calculation. In this way, the 9-speed of the lead screw under test can be reduced when calculating the transmission efficiency. n However, it should be noted that this transmission efficiency formula is a steady-state calculation formula, that is, it is based on the speed of a specific lead screw under test. n Calculate the transmission efficiency η of the ball screw nut pair at this data point. However, when the rotational speed of the screw under test is changed... n At this time, it will affect the transmission efficiency of the system by changing the lubrication state, temperature rise effect and dynamic effect, so it is necessary to systematically change the speed of the lead screw 9 under test. n For each data point, calculate the transmission efficiency. η .

[0077]

[0078] Then, the controller adjusts the nut under test 8 back to its initial position, disassembles the ball screw nut assembly under test, loosens the fastening screws of the nut under test clamping bracket 161 and the nut clamping block 162, removes the limiting pins of the dovetail groove slider 304 of the screw support seat and the dovetail groove base 305 of the screw support seat, and moves the ball screw nut assembly under test together with the screw support seat 301 and the dovetail groove slider 304 of the screw support seat along the screw support seat. Slide out the dovetail groove base 305, and then slide the next assembled ball screw nut pair to be tested, the ball screw support 301 to be tested, and the dovetail groove slider 304 of the ball screw support 305 into the ball screw support 305 to be tested, so that the external hexagonal transmission shaft 10 is inserted into the internal hexagonal hole of the ball screw 9 to be tested. Tighten the fastening screws of the nut clamping bracket 161 and the nut clamping block 162 to be tested, and prepare to start the test of the next ball screw nut pair to be tested. In addition, after the tested ball screw nut pair, along with the tested screw support 301 and the dovetail groove slider 304 of the tested screw support 301, slides out along the dovetail groove base 305 of the tested screw support 301, the tested ball screw nut pair can be removed from the tested screw support 301, and then the untested tested ball screw nut pair can be installed for replacement after the next test. This process does not take up testing time or the time for replacing the tested ball screw nut pair. It can achieve the clamping and fixing of the same specification of tested ball screw nut pairs in a simple, quick and easy manner, improving the testing efficiency of the testing equipment.

[0079] Then, the test process ends, and the host computer outputs the test report of the ball screw nut assembly under test, checking its load-power-speed curve and load-efficiency-speed curve, and determining whether the ball screw nut assembly under test meets the requirements.

Claims

1. A device for testing the transmission power and efficiency of a ball screw nut pair, characterized in that, It includes a lead screw drive device, a load loading device, a load transmission device, a nut clamping device, a lead screw drive device, a torque measurement and transmission device, and a displacement measurement device. It also includes a guide rail and a guide rail base. The guide rail base is symmetrically fixed to the base, and the guide rail is symmetrically fixed to the guide rail base. The first guide rail slider group and the second guide rail slider group are installed on the guide rail. The first guide rail slider group is fixed with a load loading device, and the second guide rail slider group is fixed with a nut clamping device to be tested. The loading screw drive device is connected to the load loading device; the load loading device is connected to the load transmission device. The load transfer device includes a first ball-joint floating joint, a second ball-joint floating joint, a floating joint connector, a floating joint connector base, and a pressure sensor. One end of the first ball-joint floating joint is fixed to a loading nut via a loading bracket. The other end of the first ball-joint floating joint is connected to the second ball-joint floating joint via the floating joint connector. The threads of the first and second ball-joint floating joints are opposite in direction. The second ball-joint floating joint is fixed to the floating joint connector base. The floating joint connector base is connected to one end of the pressure sensor, and the pressure sensor is connected to the nut clamping device to be tested. The aforementioned nut clamping device is used to fix the nut to be tested; The test lead screw drive device is connected to the test lead screw through a torque measurement and transmission device, and the test lead screw is engaged with the test nut; The lead screw to be tested is positioned by the dovetail groove slider of the lead screw support device cooperating with the dovetail groove base on the base; The displacement measuring device is used to measure the displacement of the nut clamping device under test; The load loading device includes a loading screw and a loading nut; the loading screw and the loading nut are threaded together, the loading nut is fixed on the first guide rail slider group, and the first guide rail slider group is engaged with the guide rail; the loading screw is connected to a loading screw drive device. The nut clamping device includes a nut clamping frame, a nut clamping block, and a clamping device top plate. The nut clamping frame is fixed to the clamping device top plate, and the clamping device top plate is fixed to a second guide rail slider assembly. The second guide rail slider assembly cooperates with the guide rail to restrict the rotation of the nut under test. The nut clamping frame is fixed to the nut clamping block, which has a hollow structure with square grooves on its first and second end faces adapted to the size of the nut under test. Stepped short cylindrical shafts are provided on both end faces of the nut under test.

2. The ball screw nut pair transmission power and efficiency testing device as described in claim 1, characterized in that, The test ball screw drive device includes a test ball screw drive servo motor and a drive motor mounting base; the test ball screw drive servo motor and the drive motor mounting base are locked together; the motor shaft of the test ball screw drive servo motor is connected to a torque measurement and transmission device through a third coupling, outputting drive torque, and the torque is transmitted to the external hexagonal transmission shaft through the torque measurement and transmission device, causing it to rotate, thereby driving the test ball screw nut pair to move.

3. The ball screw nut pair transmission power and efficiency testing device as described in claim 2, characterized in that, The torque measurement and transmission device includes a second coupling, a third coupling, a torque sensor, and an external hexagonal transmission shaft. The first shaft of the torque sensor is connected to the motor shaft of the ball screw drive servo motor under test through the third coupling, and the second shaft of the torque sensor is connected to the second end of the external hexagonal transmission shaft fixed in the transmission shaft fixing seat through the second coupling, so as to realize torque transmission and accurately measure the driving torque of the ball screw nut pair under test.

4. The ball screw nut pair transmission power and efficiency testing device as described in claim 3, characterized in that, The first end of the lead screw to be tested has an internal hexagonal hole, which is connected to the external hexagonal column on the external hexagonal transmission shaft to transmit rotational motion. The second end of the lead screw to be tested is installed in the lead screw support device.

5. The ball screw nut pair transmission power and efficiency testing device as described in claim 1, characterized in that, It also includes a first limiting device and a second limiting device, wherein the first limiting device is used to limit the safe position of the load loading device; and the second limiting device is used to limit the safe position of the nut clamping device to be tested.

6. A test method based on the ball screw nut pair transmission power and efficiency testing device according to any one of claims 1-5, characterized in that, as follows: The lead screw drive device under test, as the main drive end of the system, is responsible for generating and controlling the rotational motion of the lead screw under test, simulating the input conditions during actual operation. The rotational motion of the lead screw under test is converted into linear motion by the nut under test, driving the nut clamping device to move along the guide rail; The load loading device is responsible for applying a precise and controllable axial load to the nut under test; Receive the force signal detected by the pressure sensor F actual and compare it with the target value F target Compare and calculate the force error. e = F target - F actual ; Based on the error, proportional, integral, and differential operations are performed to generate a corrected torque command. T cmd Torque command T cmd The torque is sent to the loading screw drive; the loading screw drive precisely outputs the corresponding torque, which is converted into a linear force by the loading ball screw nut pair, and then applied to the nut under test through the load transmission device; the above process cycles at a frequency of several kilohertz, forming a dynamic balance system, thus... F actual Capable of fast and stable tracking F target ; Then the torque measuring and transmission device directly measures the input torque. T in and the speed of the lead screw to be measured n Pressure sensor directly measures F actual The displacement measuring device directly measures the moving speed of the nut clamping device under test. V Simultaneously collect data from all sensors and perform real-time calculation of effective power. P 2 and transmission efficiency η .

7. The test method of the ball screw nut pair transmission power and efficiency test device as described in claim 6, characterized in that, The effective power P The calculation method for 2 is as follows: 。 8. The test method of the ball screw nut pair transmission power and efficiency test device as described in claim 6, characterized in that, The transmission efficiency η The calculation method is as follows: in, P The lead of the lead screw to be tested is given.

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