Constant-force-loading miniature ball screw pair rapid service life testing device

Abstract

The invention discloses a constant force loading miniature ball screw pair rapid life test device comprising a lathe bed used for fixing a servo motor, a ball screw pair mounting seat, a horizontal linear sliding pair and a group of pulley assemblies; the fixed servo motor is connected with the tested micro ball screw pair; the ball screw pair mounting seat is used for mounting and supporting a tested micro ball screw pair; the force sensor connecting rod is connected to the tested micro ball screw pair and is connected with the steel wire rope pull rod; the wire rope pull rod is used for fixing one ends of two wire ropes; the bearing workbench is fixed on the horizontal linear sliding pair; the pulley assembly bearing frame is used for mounting the vertical linear sliding pair and the two groups of pulley assemblies; the steel wire rope lock catch is connected with the loading device and is used for fixing the other ends of the two steel wire ropes; the loading counterweight device is used for providing constant loading forces with different magnitudes; the vertical linear sliding pair is used for guiding the loading counterweight device in the vertical direction; the system can be increased or decreased according to actual working condition load requirements.

Description

Technical Field

[0001] This invention belongs to the field of ball screw pair testing, and in particular, a rapid life testing device for a miniature ball screw pair under constant force loading. Background Technology

[0002] A ball screw is a precision rolling functional component capable of converting between rotary and linear motion. As a transmission component, ball screws are widely used in CNC machine tools, industrial robots, automobiles, aerospace, and other fields, where their application places stringent requirements on lifespan. Different applications and operating conditions impose varying lifespan requirements on ball screws, and the fatigue life of a ball screw has a significant impact on the accuracy and reliability of the transmission component. However, testing the entire lifespan of a ball screw requires substantial time and effort, often failing to meet the time constraints of product development cycles. Therefore, rapid life testing is often the preferred method for shortening development cycles and reducing costs.

[0003] Currently, the main methods for rapid life testing of ball screw pairs include load methods such as dampers, eddy current brakes, and magnetic powder brakes. However, none of these methods can maintain a constant load force. Furthermore, simulating actual working conditions is difficult, installation is complex, multiple working conditions cannot be achieved simultaneously, and the cost is high. They also cannot achieve continuous constant load output under a specific working condition or several working conditions, which affects the final rapid life test results. Summary of the Invention

[0004] The purpose of this invention is to provide a rapid life testing device for a micro ball screw pair under constant force loading, so as to detect the operating life of the micro ball screw pair.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A rapid life testing device for a miniature ball screw pair under constant force loading includes:

[0007] The bed is used to fix the servo motor, ball screw pair mounting base, horizontal linear sliding pair and a set of pulley assembly;

[0008] A fixed servo motor is connected to the nut of the tested miniature ball screw pair via a coupling and a drive shaft adapter, converting the rotation of the nut into linear movement of the screw shaft.

[0009] Ball screw assembly mounting bracket, used to install and support the miniature ball screw assembly under test;

[0010] The force sensor connecting rod is connected to the wire rope tie rod of the tested miniature ball screw pair, and is used to detect the magnitude of the load force applied to the tested miniature ball screw pair in real time to meet the requirements of different working conditions.

[0011] A wire rope tie rod is fixed to the bearing workbench and is used to fix one end of two wire ropes.

[0012] The support worktable is fixed on a horizontal linear sliding pair;

[0013] The pulley assembly support frame is used to install the vertical linear sliding pair and two sets of pulley assemblies, and the two sets of pulley assemblies are positioned higher than the set of pulley assemblies fixed to the bed.

[0014] A wire rope lock, connected to the loading device, is used to secure the other end of two wire ropes.

[0015] A counterweight device is used to provide constant load forces of varying magnitudes;

[0016] A vertical linear sliding pair is used to guide the loading counterweight device in the vertical direction;

[0017] The three sets of pulley assemblies mentioned above are used in conjunction with two steel wire ropes to convert the weight of the loading device into an axial load on the tested miniature ball screw pair in the horizontal direction.

[0018] The significant advantages of this invention compared to existing technologies are:

[0019] This invention enables speed control and real-time load detection under different operating conditions by setting speed and force sensors for the servo motor. The constant force loading method using loading mass blocks more stably simulates actual operating load conditions. By controlling the number of loading mass blocks, the load requirements under different operating conditions can be met, allowing for rapid switching between different load stages of the ball screw pair's rapid lifespan, thus improving testing efficiency. Furthermore, by changing the ball screw pair mounting fixture, it can even accommodate testing of different models of ball screw pairs, demonstrating good adaptability. At the same time, by placing the loading mass blocks inside the loading support frame, the loading mass blocks can be installed and removed simply according to the actual operating load, making the operation convenient, safe, time-saving, and labor-saving. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the drive mechanism structure of the present invention;

[0022] Figure 3 This is a front view of the counterweight loading device of the present invention;

[0023] In the diagram: 1. Bed; 2. Servo motor; 3. Motor mounting base; 4. Mounting base plate; 5. Coupling; 6. Adapter drive shaft; 7. Ball screw pair mounting base; 8. Miniature ball screw replica; 9. Bearing cover; 10. Force sensor connecting rod; 11. S-shaped force sensor; 12. Load-bearing worktable; 13. Wire rope tie rod; 14. Wire rope; 15. Wire rope lock; 16. Slider; 17. Guide rail; 8. Guide rail adapter plate; 19. Pulley assembly; 20. Pulley assembly pad; 21. Pulley assembly load-bearing frame; 22. Loading connection cover plate; 23. Lifting lug; 24. Guide rail mounting plate; 25. Guide rail; 26. Guide slider; 27. Loading load-bearing frame top plate; 28. Loading load-bearing frame; 29. ​​Loading mass block; 30. Loading mass block limit rod; 31. Loading mass block connecting side plate; 32. Rubber buffer pad. Detailed Implementation

[0024] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0025] like Figure 1 , Figure 2 , Figure 3 As shown in the figure, an embodiment of the present invention proposes a rapid life testing device for a miniature ball screw pair under constant force loading, comprising a bed 1, a motor mounting base 3, a ball screw pair mounting base 7, a bearing worktable 12, three sets of pulley assemblies 19, and a loading bearing frame 28. The top of the bed 1 has a mounting hole, and a mounting base plate 4, a guide rail adapter plate 18, a pulley assembly plate 20, and a pulley assembly load-bearing frame 21 are fixedly connected to it by bolts. The bottom of the motor mounting base 3 has a countersunk hole, which is connected to the mounting base plate 4 by bolts. The panel of the motor mounting base 3 has a threaded hole, and a servo motor 2 is fixedly mounted thereon. The bottom of the ball screw pair mounting base 7 has a countersunk hole, which is fixedly connected to the mounting base plate 4 by bolts.

[0026] The ball screw pair mounting base 7 has an inner hole that mates with the miniature ball screw replica 8. After the miniature ball screw replica 8 is installed inside the ball screw pair mounting base 7, the ball screw pair is axially fixed by the bearing cap 9. The servo motor 2 is connected to one end of the miniature ball screw replica 8 via a coupling and a drive shaft 5. The other end of the miniature ball screw replica 8 is connected to one end of an S-shaped force sensor via a force sensor connecting rod. The other end of the S-shaped force sensor is connected to a wire rope tie rod 13. The wire rope tie rod 13 has a U-shaped structure and is fixed on the bearing worktable 12. The bearing worktable 12 is fixedly connected to the slider 16 via bolts. The slider 16 is mounted on the guide rail 17. The guide rail 17 is fixedly mounted on the guide rail adapter plate 18. One set of pulley assemblies 19 is fixed on the bed 1. The other two sets of pulley assemblies 19 are connected to the pulley assembly pad 20 via bolts. The pulley assembly pad 20 is fixed on the pulley assembly support frame 21. The two sets of pulley assemblies 19 located on the pulley assembly support frame 21 are positioned higher than the set of pulley assemblies 19 located on the bed 1.

[0027] Each pulley assembly 19 includes two parallel fixed pulleys. Wire ropes 14 are fixed to both ends of the wire rope rod 13 via wire rope locks 15. The two wire ropes 14 pass through the three pulley assemblies 19 and are connected to the lifting lugs 23 of the loading device via the wire rope locks 15. The three pulley assemblies 19 and the wire rope rod 13 convert the vertical moving load of the loading device into a horizontal axial load from the ball screw pair.

[0028] The lifting lug 23 of the loading counterweight device is fixedly connected to the top of the loading connection cover plate 22. The loading connection cover plate 22 has threaded holes on two sides, and guide sliders 26 are connected by bolts. The guide sliders 26 are installed and connected to the guide rails 25. The guide rails 25 are fixedly installed on the guide rail mounting plate 24 by bolts. The guide rail mounting plate 24 is fixed inside the pulley assembly load-bearing frame 21 by welding on both sides. The guide sliders 26 and the guide rails 25 guide the vertical movement of the loading device, thereby preventing the loading device from overturning and shaking when it moves up and down.

[0029] The loading connection cover plate 22 has four bolt holes and is fixedly connected to the top plate 27 of the loading support frame by bolts. The bottom of the top plate 27 of the loading support frame is connected to the loading support frame 28 by welding. The loading support frame 28 is used to support the loading mass block. The loading mass block limiting rod 30 is welded and fixed to the center of the top and bottom surfaces inside the loading support frame 28. The loading mass block limiting rod 30 cooperates with the loading mass block 29 with a U-shaped elongated hole to limit the loading mass block 29 and prevent it from slipping. At the same time, the weight of the loading mass block 29 can be customized according to the actual working condition load requirements of the ball screw pair to meet the load requirements of different models of ball screw pairs and the different working condition load requirements of the same model of ball screw pair.

[0030] The loading mass block 29 has threaded holes on its side and top to facilitate handling, installation, and disassembly. After the loading mass block 29 is installed, adjacent loading mass blocks 29 are connected and fixed by the loading mass block connecting side plate 31 to prevent the loading mass blocks 29 from slipping or falling off during the test. At the same time, the loading mass block 29 can be installed or disassembled according to the actual working load. It has the characteristics of convenient operation, saving time and effort, and can efficiently realize the switching of different working loads.

[0031] Two rubber buffer pads 32 are placed on the ground directly below the loading support frame 28 to facilitate the replacement of the miniature ball screw replica 8 or the installation and removal of the loading mass block 29. They also serve as a buffer in case of abnormal situations during the test to prevent safety accidents.

[0032] By adjusting the number of loading mass blocks 29, the requirements of different working conditions and loads can be achieved. In summary, during the rapid life test of a miniature ball screw pair, the speed and acceleration of the servo motor can be set by the CNC system, and the number of loading mass blocks can be controlled to achieve the setting of speed, acceleration, and constant force load under different working conditions. Simultaneously, the ball screw pair lead can be set according to the design parameters, which can control the effective stroke of the rapid life test, thereby enabling rapid life testing of the miniature ball screw pair under different working conditions.

[0033] like Figure 2 As shown, in some embodiments, the ball screw assembly mounting base 7 can be designed and replaced according to the structure of different models of ball screw assemblies, which can realize rapid life testing of different models of ball screw assemblies.

[0034] like Figure 1 , Figure 2As shown, in some embodiments, the speed and acceleration of the servo motor 2 can be set by the CNC system to achieve speed and acceleration control under different working conditions. The S-shaped force sensor 11 can detect the magnitude of the real-time load, that is, the magnitude of the real-time load force applied to the end of the lead screw shaft, so as to accurately meet the requirements of different working conditions by controlling the motor.

[0035] like Figure 1 , Figure 3 As shown, in some embodiments, the load-bearing workbench 12 is connected to the lifting lug 23 of the loading counterweight device by passing a steel wire rope 14 through three pulley assemblies 19. By arranging the positions of the three pulley assemblies 19, the weight of the loading device containing the loading mass block 29 is converted into an axial load of the horizontal ball screw pair.

[0036] like Figure 3 As shown, in some embodiments, the two sides of the loading connection cover plate 22 are bolted to guide sliders 26 and guide rails 25 to guide the loading load frame 28 when it moves up and down, and to prevent the loading device from overturning and shaking when it moves up and down.

[0037] like Figure 3 As shown, in some embodiments, the loading mass block 29 is placed inside the loading support frame 28. The loading mass block 29 can be installed and removed according to the actual working load, which is convenient, time-saving and labor-saving. At the same time, the weight of the loading mass block 29 can be customized according to the actual working load requirements of the ball screw pair to meet the load requirements of different models of ball screw pairs and the different working conditions of the same model of ball screw pair.

[0038] like Figure 3 As shown, in some embodiments, two rubber buffer pads 32 are placed on the ground directly below the loading support frame 28. This allows for placement when the miniature ball screw replica 8 needs to be replaced or the loading mass block 29 needs to be installed or removed. It also provides cushioning in case of abnormal situations during the test, so as to prevent the loading support frame 28 from falling to the ground and causing safety accidents.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rapid life testing device for a miniature ball screw pair under constant force loading, characterized in that, include: The bed is used to fix the servo motor, ball screw pair mounting base, horizontal linear sliding pair and a set of pulley assembly; A fixed servo motor is connected to the nut of the tested miniature ball screw pair via a coupling and a drive shaft adapter, converting the rotation of the nut into linear movement of the screw shaft. Ball screw assembly mounting bracket, used to install and support the miniature ball screw assembly under test; The force sensor connecting rod is connected to the wire rope tie rod of the tested miniature ball screw pair, and is used to detect the magnitude of the load force applied to the tested miniature ball screw pair in real time to meet the requirements of different working conditions. A wire rope tie rod is fixed to the bearing workbench and is used to fix one end of two wire ropes. The support worktable is fixed on a horizontal linear sliding pair; The pulley assembly support frame is used to install the vertical linear sliding pair and two sets of pulley assemblies, and the two sets of pulley assemblies are positioned higher than the set of pulley assemblies fixed to the bed. A wire rope lock, connected to the loading device, is used to secure the other end of two wire ropes. A counterweight device is used to provide constant load forces of varying magnitudes; A vertical linear sliding pair is used to guide the loading counterweight device in the vertical direction; The three sets of pulley assemblies mentioned above are used in conjunction with two steel wire ropes to convert the weight of the loading device into an axial load on the tested miniature ball screw pair in the horizontal direction.

2. The rapid life testing device for a micro ball screw pair under constant force loading according to claim 1, characterized in that, The loading device includes a loading connecting cover plate, a loading support frame top plate, a loading support frame, and a loading mass block; the loading connecting cover plate is fixedly connected to the loading support frame top plate, the bottom of the loading support frame top plate is connected to the loading support frame, and the loading support frame is used to support the loading mass block.

3. The rapid life testing device for a micro ball screw pair under constant force loading according to claim 2, characterized in that, The loading support frame has a loading mass block limiting rod fixed at the center of its top and bottom surfaces. The loading mass block limiting rod cooperates with the loading mass block with a U-shaped hole to limit the loading mass block.

4. The rapid life testing device for a micro ball screw pair under constant force loading according to claim 2, characterized in that, The loading mass block has threaded holes on its side and top as handling and installation holes. Adjacent loading mass blocks are connected and fixed by the loading mass block connecting side plate.

5. The rapid life testing device for a micro ball screw pair under constant force loading according to claim 2, characterized in that, A rubber cushioning pad is placed on the ground directly below the loading support frame.

6. The rapid life testing device for a miniature ball screw pair under constant force loading according to claim 1, characterized in that, The horizontal linear sliding pair includes a slider and a guide rail; the bearing worktable is fixedly connected to the slider, the slider is mounted on the guide rail, the guide rail is fixedly mounted on the guide rail adapter plate, and the guide rail adapter plate is fixed to the bed.

7. The rapid life testing device for a micro ball screw pair under constant force loading according to claim 2, characterized in that, The vertical linear sliding pair includes a guide slider and a guide rail; the loading connection cover plate is connected to both sides of the guide slider; the guide slider is installed and connected to the guide rail, the guide rail is fixedly installed on the guide rail mounting plate, and the guide rail mounting plate is fixed inside both sides of the pulley assembly load-bearing frame.

8. The rapid life testing device for a miniature ball screw pair under constant force loading according to claim 1, characterized in that, The top of the bed has mounting holes, and a mounting base plate is fixedly connected to it by bolts; the motor mounting base is connected to the mounting base plate by bolts.

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