Robot joint accelerated fatigue testing device and testing method thereof
By employing magnetic levitation positioning and automated feeding technologies, the problem of low efficiency in existing robot joint bearing testing equipment has been solved, enabling efficient and accurate accelerated fatigue testing, which is suitable for robot joint bearings in new energy vehicle production.
Patent Information
- Application Number
- CN202511713273.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-02-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing accelerated fatigue testing equipment for robot joint bearings is inefficient, cannot perform continuous testing, and suffers from large fluctuations in vibration transmission and radial pressure application accuracy due to rigid supports, affecting the accuracy of test data.
By employing closed-loop magnetic levitation positioning technology using radial and axial electromagnets, combined with laser displacement sensors and robotic arm grippers, non-contact levitation positioning and automated continuous feeding of bearings are achieved. Pressure rollers simulate the radial load conditions of the bearings, and limit wheels prevent rotation, ensuring the stability and efficiency of the testing process.
This technology enables efficient accelerated fatigue testing of robot joint bearings, improving testing efficiency, reducing downtime caused by mechanical obstruction, ensuring the accuracy and safety of test data, and is applicable to bearing materials with different magnetic permeability characteristics.
Smart Images
Figure CN121475680A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of robot testing for new energy vehicle production, in particular to a robot joint acceleration fatigue testing device and a testing method thereof. BACKGROUND
[0002] New energy driven vehicles such as plug-in hybrid drive, pure electric drive and fuel cell drive are always in high intensity work, so it is necessary to test the robot joint bearing. The bearing is the core load-bearing component of the robot joint, and its fatigue life directly determines the reliability and service life of the robot. Therefore, the mechanical properties and durability of the bearing need to be verified through acceleration fatigue testing before leaving the factory. At present, the mainstream robot joint bearing acceleration fatigue testing equipment in the industry still has certain technical defects, and it is difficult to meet the efficient and continuous testing requirements.
[0003] Specifically, such equipment mechanically limits the bearing shaft to be tested through a fixed support, then applies radial load to the bearing through a pressure applying mechanism, and drives the bearing to rotate to realize fatigue testing. However, since the rigid support and the bearing shaft are physically connected, the support itself will form an axial block, which will cause the testing process to be temporarily suspended when the bearing is loaded and unloaded (the bearing that has been tested needs to be removed from one side of the support first), and then the bearing to be tested needs to be manually or through a simple mechanism installed on the testing station of the bearing shaft. Single test can only handle a single or small number of bearings, the testing gap is long, the efficiency is low, and it cannot meet the rapid detection requirements of large quantities of bearings. At the same time, the mechanical constraint of the rigid support easily causes vibration transmission, resulting in large fluctuations in radial pressure application accuracy, and further causing distortion of the test data.
[0004] To solve the above problems, a robot joint acceleration fatigue testing device and a testing method thereof are provided. SUMMARY
[0005] To solve the above technical problems, a robot joint acceleration fatigue testing device and a testing method thereof are provided, which solve the problems raised in the background art.
[0006] To achieve the above purposes, the following technical solutions can be used: The present application provides a robot joint acceleration fatigue testing device, comprising: A force applying assembly comprising an electric cylinder one fixedly installed on the top of the cabinet, a wheel frame fixedly connected to the bottom of the extension end of the electric cylinder one, and a pressure roller rotatably connected to the bottom of the wheel frame; A bearing assembly comprising a suspension shaft arranged in the middle of the cabinet, two groups of radial electromagnets arranged on both sides of the suspension shaft, and two axial electromagnets arranged at both ends of the suspension shaft along the axial direction of the suspension shaft, each group of radial electromagnets has three, which are arranged in a ring array around the axis of the suspension shaft; and The feeding assembly comprises a linear module fixedly installed below the cabinet, a U-shaped frame fixedly installed on the top of the sliding block of the linear module, two groups of limiting wheels rotatably connected to the top of the two sides of the U-shaped frame, four limiting wheels in each group arranged in a symmetrical manner, a push block fixedly connected to the two sides of one end of the U-shaped frame, and a mechanical arm gripper fixedly installed on the side of the cabinet.
[0007] Further, the pressure roller is parallel to the suspension shaft and located directly above the suspension shaft, one end of the pressure roller is fixedly connected with a motor, and the shell of the motor is fixedly installed at one end of the wheel frame.
[0008] Further, a pressure sensor is fixedly installed between the top of the wheel frame and the extension end of the first electric cylinder.
[0009] Further, guide rods one are fixedly connected to the top of the wheel frame, and the outer portions of the two guide rods one are correspondingly slidably connected inside the cabinet.
[0010] Further, the two groups of radial electromagnets are fixedly connected with the cabinet, the two axial electromagnets are fixedly connected with the cabinet, the laser displacement sensors are fixedly installed at the centers of the radial electromagnets and the axial electromagnets, and the laser beams emitted by the laser displacement sensors should be perpendicular to the surface of the suspension shaft.
[0011] Further, the distance between the two groups of limiting wheels is consistent with the diameter of the suspension shaft, the rotation axes of the limiting wheels are perpendicular to the axis of the suspension shaft, and when the wheel surface of the limiting wheel abuts against the axial surface of the suspension shaft, the friction therebetween can prevent the suspension shaft from rotating.
[0012] Further, the auxiliary assembly comprises a lifting cross bar arranged directly below the suspension shaft, springs fixedly connected to the top of the lifting cross bar, a lifting fork fixedly connected to the top of the springs, and a second electric cylinder fixedly connected to the bottom center of the lifting cross bar, and the second electric cylinder is fixedly installed below the cabinet.
[0013] Further, guide rods two are fixedly connected to the bottom of the lifting cross bar, and the outer portions of the two guide rods two are correspondingly slidably connected inside the cabinet.
[0014] Further, a test method for robot joint acceleration fatigue test comprises the following steps: S1, the suspension shaft is lifted to the center of the two groups of radial electromagnets by the auxiliary assembly, the radial electromagnets and the axial electromagnets work, the auxiliary assembly is reset, the suspension shaft is suspended in space by the radial and axial magnetic attraction force formed, and the data is detected by the laser displacement sensor, and the space is accurately positioned by adjusting the magnetic attraction force. S2, the robot joint bearing is grabbed from the tray by the mechanical arm gripper in the feeding assembly, and then is transferred to one end of the suspension shaft and is located between the suspension shaft and the axial electromagnet at the end, at which time the bearing inner ring should be aligned with the suspension shaft; S3, the U-shaped frame on the sliding block is moved by the linear module, and then the push block is abutted against the inner ring of the bearing from one side of the bearing, the linear module continues to act, the mechanical arm gripper is loosened, and finally the bearing is sleeved on the suspension shaft due to being pushed; S4, repeat steps S2 and S3 to sleeve the bearings to be tested on the suspension shaft one by one, and then the roller is lowered by the force assembly until the wheel surface is abutted against the outer ring of the bearing, and the radial force of the bearing is detected by the pressure sensor, and then the rotation of the bearing outer ring is driven by the rotation of the roller, so as to simulate the working condition of the bearing in the robot joint under load, and at the same time when the roller is pressed down, the bearing assembly should adjust the position of the suspension shaft in time to avoid the influence of inaccurate positioning of the suspension shaft on the stability of the test; S5, during the test, the push block is slowly pushed along the axial direction of the suspension shaft, so as to drive the bearing string to move along the axial direction of the suspension shaft, and the limiting wheel is abutted against the axial surface of the suspension shaft, the self-rotation of the suspension shaft is blocked by the friction force, the friction force between the suspension shaft and the bearing inner ring after limiting the self-rotation is limited, so as to avoid the inertia of the inner ring rotating with the outer ring, and after the test time meets the requirement, the farthest bearing will be pushed off the suspension shaft, during the test process, the remaining bearings to be tested can be supplemented in time without pausing the test, and the test efficiency is improved.
[0015] As described above, the robot joint accelerated fatigue test device and the test method have the following characteristics and advantages: The problems of low efficiency and discontinuous bearing fatigue test in the prior art are solved, and the physical blocking defect of the traditional support is avoided: in the prior art, the bearing test equipment usually uses a rigid support to support the bearing shaft, the support forms a physical block, which causes the bearing loading and unloading to be operated in a stopped state, and the number of single test is limited, and the test efficiency is extremely low, the present application replaces the traditional support with a "radial + axial electromagnet closed loop magnetic suspension positioning" mechanism, which has no physical block, and cooperates with the automatic continuous feeding mechanism of the mechanical arm gripper and the linear module to continuously supplement the bearings to be tested without pausing the test, the bearing string is smoothly transferred along the suspension shaft and is automatically unloaded, which completely avoids the disadvantages of the traditional support "stopping for loading and unloading", and also avoids the mechanical constraint of the rigid support which is easy to produce vibration transmission and causes the radial pressure to fluctuate, greatly improves the accelerated fatigue test efficiency of the robot joint bearing for new energy automobile production, and the cooperative adjustment of the laser displacement sensor and the electromagnet can ensure the positioning accuracy of the suspension shaft and the stability of the radial pressure, and solves the core problem of inaccurate positioning of the suspension type scheme.
[0016] The scheme supports flexible switching of double test modes, can stably test ceramic bearings and the like low-permeability material bearings through electromagnetic magnetic suspension positioning, can adapt to high-permeability material bearings through auxiliary assembly lifting suspension shaft cooperation pressure test, can cover the test requirements of robot joint bearing of different permeability characteristics without replacing core components, is wide in application range and simple in switching operation, improves the comprehensive utilization rate of the equipment, and simultaneously, the bearing assembly has dual functions of suspension shaft precise positioning and accidental falling protection, the lifting fork of the auxiliary assembly can support the suspension shaft when the magnetic suspension fails or the equipment is abnormal, forms double safety protection, effectively avoids equipment damage or test accidents caused by the falling of the suspension shaft, and significantly enhances the safety redundancy of equipment operation. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is an overall structural schematic diagram of robot joint accelerated fatigue test shown in the application. Figure 2 It is another view schematic diagram of the structure. Figure 1 Figure 3 It is a pressure sensor structure assembly schematic diagram of the robot joint accelerated fatigue test shown in the application. Figure 4 It is an assembly schematic diagram of the radial electromagnet structure of the robot joint accelerated fatigue test shown in the application relative to the suspension shaft. Figure 5 It is a laser displacement sensor structure assembly schematic diagram of the robot joint accelerated fatigue test shown in the application. Figure 6 It is a partial feed assembly structure schematic diagram of the robot joint accelerated fatigue test shown in the application. Figure 7 It is an assembly schematic diagram of the limiting wheel structure of the robot joint accelerated fatigue test shown in the application relative to the suspension shaft. Figure 8 It is a test method flowchart of the robot joint accelerated fatigue test shown in the application.
[0018] In the application, the reference signs are as follows: Force applying assembly: 11, electric cylinder one; 12, wheel frame; 13, pressure roller; 14, motor; 15, guide rod one; 16, pressure sensor; Bearing assembly: 21, suspension shaft; 22, radial electromagnet; 23, axial electromagnet; 24, laser displacement sensor; Feed assembly: 31, linear module; 32, U-shaped frame; 33, limiting wheel; 34, push block; 35, mechanical arm clamping jaw; Auxiliary assembly: 41, lifting cross rod; 42, spring; 43, lifting fork; 44, electric cylinder two; 45, guide rod two. DETAILED DESCRIPTION
[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.
[0020] Referring to Figures 1-8 As shown in the embodiments of the present application, a robot joint accelerated fatigue test device and a test method thereof will be described in detail as follows: Referring to Figures 1-3 As shown in the embodiments of the present application, a robot joint accelerated fatigue test device comprises a force applying assembly, which comprises an electric cylinder one 11 fixedly installed on the top of a cabinet, a wheel frame 12 fixedly connected at the bottom of the telescopic end of the electric cylinder one 11, and a pressure roller 13 rotationally connected at the bottom of the wheel frame 12. Further, one end of the pressure roller 13 is fixedly connected with a motor 14, the shell of the motor 14 is fixedly installed at one end of the wheel frame 12, a pressure sensor 16 is fixedly installed between the top of the wheel frame 12 and the telescopic end of the electric cylinder one 11, and guide rods one 15 are fixedly connected at both sides of the top of the wheel frame 12, and the outer portions of the two guide rods one 15 are correspondingly slidably connected inside the cabinet.
[0021] Referring to Figures 1-2 and Figures 4-5 As shown in the embodiments of the present application, the robot joint accelerated fatigue test further comprises a bearing assembly, which comprises a suspension shaft 21 arranged in the middle of the cabinet, two groups of radial electromagnets 22 arranged at both sides of the suspension shaft 21, and two axial electromagnets 23 arranged at both ends of the suspension shaft 21 along the axial direction of the suspension shaft 21. Each group of radial electromagnets 22 has three radial electromagnets 22 arranged in a ring array with the axis of the suspension shaft 21 as the center (the included angle between the three radial electromagnets 22 is 120°, and each radial electromagnet 22 is arranged along the radial direction of the suspension shaft 21). Further, the pressure roller 13 and the suspension shaft 21 are parallel to each other and located directly above the suspension shaft 21. The two groups of radial electromagnets 22 are fixedly connected with the cabinet, and the two axial electromagnets 23 are fixedly connected with the cabinet (each electromagnet is rigidly connected with the cabinet, thereby providing a mechanical basis for the stable suspension of the suspension shaft 21). Laser displacement sensors 24 are fixedly installed at the centers of each radial electromagnet 22 and axial electromagnet 23, and the laser beams emitted by the laser displacement sensors 24 should be perpendicular to the surface of the suspension shaft 21.
[0022] Referring to Figures 1-2 and Figures 6-7As shown, the robot joint acceleration fatigue test also includes a feeding assembly, which includes a linear module 31 fixedly installed below the cabinet, a U-shaped frame 32 fixedly installed on the top of the slider of the linear module 31, two sets of limiting wheels 33 rotatably connected to the top of both sides of the U-shaped frame 32, each set of limiting wheels 33 having four, which are arranged in a symmetrical form from top to bottom, a push block 34 fixedly connected to both sides of one end of the U-shaped frame 32, and a mechanical arm gripper 35 fixedly installed on the side of the cabinet. Further, the spacing between the two sets of limiting wheels 33 is consistent with the diameter of the suspension shaft 21, the rotational axis of each limiting wheel 33 is perpendicular to the axis of the suspension shaft 21, and when the wheel surface of the limiting wheel 33 abuts on the shaft surface of the suspension shaft 21, the friction therebetween can prevent the suspension shaft 21 from rotating. In the present embodiment, in order to improve the friction between the limiting wheel 33 and the suspension shaft 21, the material thereof is preferably rubber.
[0023] It should be noted that the above-mentioned mechanical arm gripper 35 is a prior art, i.e. the combination of an industrial robot arm and a gripper. The mechanical arm gripper 35 is the core automated feeding execution component of the test scheme, and the core function is to accurately grasp, position and complete the sleeve shaft action of the robot joint bearing in cooperation with the feeding assembly, which is suitable for the continuous testing requirement without stopping.
[0024] The core features are as follows: Structural adaptation: flexible clamping design (such as pneumatic finger gripper) is adopted, the contact surface of the gripper is adapted to the profile of the bearing outer ring, which avoids damaging the bearing surface during clamping and ensures the stability of grasping; Motion coordination: after grasping the bearing from the tray according to the preset program, the bearing inner ring is aligned with the axis of the suspension shaft 21, and the push block 34 abuts against the bearing inner ring, and then the sleeve shaft action is synchronized and released without interference; Precision matching: high clamping and positioning precision, cooperation with the positioning system of the linear module 31 and the suspension shaft 21 to ensure smooth bearing sleeve shaft without deviation and jamming; Flexible replenishment: supports replenishment during testing without stopping, can repeatedly execute grasping-positioning-releasing actions, and continuously replenishes the bearings to be tested in cooperation with the bearing string transfer rhythm, thereby improving the testing efficiency.
[0025] Further, the robot joint acceleration fatigue test also includes an auxiliary assembly, which includes a lifting cross bar 41 arranged directly below the suspension shaft 21, springs 42 fixedly connected to both sides of the top of the lifting cross bar 41, a lifting fork 43 fixedly connected to the top of the springs 42, and an electric cylinder two 44 fixedly connected to the bottom center of the lifting cross bar 41. The electric cylinder two 44 is fixedly installed below the cabinet, and the bottom of the lifting cross bar 41 is fixedly connected with guide rods two 45 on both sides. The outer portions of the two guide rods two 45 are slidingly connected to the inside of the cabinet.
[0026] The core of the above scheme is through the magnetic suspension precise positioning, automatic continuous feeding, radial pressure closed loop control, relative rotation constraint of inner and outer rings, non-stop continuous transfer of the synergistic mechanism, simulating the actual working condition of the robot joint bearing "radial load + relative rotation of inner and outer rings", realizing high efficient accelerated fatigue test, and its working principle is around the function cooperation of each component and the simulation of core working condition. I. Precise positioning principle of suspension shaft 21 (cooperation of bearing assembly and auxiliary assembly) Initial lifting and magnetic attraction establishment: before testing, the auxiliary assembly electric cylinder 44 drives the lifting cross bar 41 to rise along the guide rod 45, the lifting fork 43 holds the suspension shaft 21 through the spring 42 buffer, and the suspension shaft 21 is pre-positioned to the center area of the two groups of radial electromagnets 22, so as to avoid the failure of magnetic attraction establishment caused by initial deviation; then the radial electromagnet 22 (3 in each group in a ring array with the axis of the suspension shaft 21 as the center) and the axial electromagnet 23 are started, the radial electromagnet 22 generates uniform distributed electromagnetic attraction force, and the axial electromagnet 23 generates reverse axial magnetic attraction force, which together "attracts away" the suspension shaft 21 from the lifting fork 43, realizing the non-contact suspension in space.
[0027] Closed loop precise adjustment: the laser displacement sensor 24 in the center of each radial electromagnet 22 and axial electromagnet 23 emits a laser beam perpendicular to the surface of the suspension shaft 21, and real-time collects the radial displacement and axial displacement data of the suspension shaft 21, and feeds back to the control system; the control system dynamically adjusts the current of each electromagnet according to the deviation signal, and corrects the magnetic attraction force distribution - the radial direction offsets the pressure fluctuation, bearing transfer friction and other interference through the cooperation of the three ring arrays of electromagnets, and the axial direction balances and suppresses the movement through the attraction force of the electromagnets at both ends, so as to finally control the radial displacement of the suspension shaft 21 within the preset range, and ensure the stable positioning of the suspension shaft 21 during testing, and provide reliable radial support for the bearing.
[0028] Test state switching: after the suspension shaft 21 is positioned stably, the electric cylinder 44 drives the lifting cross bar 41 to descend, and the lifting fork 43 is completely separated from the suspension shaft 21, so as to avoid the mechanical contact affecting the rotation and axial movement of the bearing, and at the same time, the spring 42 remains in the energy storage state, so as to be ready to lift the suspension shaft 21 again after the test is completed, and at the same time, the bearing assembly also serves as a protection mechanism for the suspension shaft 21 in case of accidental falling.
[0029] II. Automatic continuous feeding principle (cooperation of feeding assembly) Precise feeding and guidance: the mechanical arm gripper 35 grabs the robot joint bearing to be tested from the tray, and transfers it to the feeding end of the suspension shaft 21 according to the preset positioning data, so that the bearing inner ring is aligned with the axis of the suspension shaft 21 (the diameter of the suspension shaft 21 is smaller than the inner diameter of the bearing inner ring, and a shaft clearance is reserved); at this time, the bearing is located between the suspension shaft 21 and the axial electromagnet 23 of the feeding end, and there is no mechanical block, which is ready for shafting.
[0030] Sleeving and queue formation: the linear module 31 drives the U-shaped frame 32 to move in the horizontal direction to the suspension shaft 21, the push block 34 at one end of the U-shaped frame 32 abuts the bearing inner ring, and the mechanical arm clamping jaw 35 is loosened synchronously under the continuous advancement of the linear module 31, the bearing is smoothly sleeved along the feeding end of the suspension shaft 21 under the axial thrust of the push block 34; repeat the above action, the newly sleeved bearing is in contact with the end face of the previous bearing to form a continuous bearing string, laying the foundation for non-stop testing; during the above sleeving operation, in order to improve the smoothness, the two ends of the suspension shaft 21 are chamfered in this embodiment.
[0031] Double action of limiting wheel 33: the two groups of limiting wheels 33 (4 up and down symmetrically arranged in each group) on the top of the U-shaped frame 32 have a spacing consistent with the diameter of the suspension shaft 21, which plays a guiding role in the bearing sleeving process, ensuring that the bearing is accurately aligned with the suspension shaft 21; on the other hand, it abuts the suspension shaft 21 shaft surface during the whole test, and the friction force between the wheel surface and the shaft surface prevents the suspension shaft 21 from rotating, providing a constraint condition for the relative rotation of the bearing inner and outer rings.
[0032] Three, radial pressure and relative rotation principle of inner and outer rings (force applying assembly + bearing assembly + feeding assembly cooperate) Radial pressure closed-loop control: after feeding is completed, the electric cylinder 11 of the force applying assembly drives the wheel frame 12 to move downward along the guide rod 15, driving the pressure roller 13 (parallel to the suspension shaft 21 and located directly above) to descend until the roller surface abuts the top of the outer ring of the bearing at the front end of the bearing string; the pressure sensor 16 between the wheel frame 12 and the electric cylinder 11 collects radial pressure data in real time, which is fed back to the control system, and when the pressure reaches the preset target value (such as 10%-30% of the rated radial load of the bearing), the electric cylinder 11 stops moving, and the pressure is maintained stable through closed-loop adjustment, simulating the radial load working condition of the robot joint bearing; similarly, in order to improve the smoothness of the bearing into the bottom of the roller, the two ends of the roller are also chamfered in this embodiment.
[0033] Relative rotation of inner and outer rings: the motor 14 at one end of the pressure roller 13 is started to drive the roller to rotate; due to the close abutment (high friction contact) of the roller and the bearing outer ring, the rotating friction drives the bearing outer ring to rotate at a high speed synchronously; at the same time, the limiting wheel 33 of the feeding assembly continuously abuts the shaft surface of the suspension shaft 21, strictly preventing the suspension shaft 21 from rotating through friction, while the bearing inner ring is in contact with the surface of the suspension shaft 21, and the inner ring remains stationary with the suspension shaft 21 by means of the friction between them, finally forming a relative rotation state of "outer ring rotation, inner ring stationary", accurately simulating the actual working motion form of the robot joint bearing, and realizing the accelerated fatigue test.
[0034] Test stability guarantee: During the test, if the suspension shaft 21 deviates due to roller pressure fluctuation and bearing rotation vibration, the laser displacement sensor 24 will feed back the deviation in real time, and the control system will immediately adjust the corresponding electromagnet current to pull the suspension shaft 21 back to the reference position; if the radial pressure deviation is detected by the pressure sensor 16, the electric cylinder 11 will adjust the lifting height in real time to ensure the pressure accuracy and avoid simulation distortion under working conditions.
[0035] Four, continuous transfer and non-stop feeding principle (supply assembly + bearing assembly cooperation) Bearing string directional transfer: During the test, the linear module 31 drives the U-shaped frame 32 to move slowly along the axis direction of the suspension shaft 21, and the push block 34 continuously applies axial thrust to the bearing string to push the bearing string to move smoothly along the suspension shaft 21 to the discharge end; Since the suspension shaft 21 is in a precise suspension state, and the bearing inner ring is in a clearance fit with the suspension shaft 21, there is no mechanical jam during the transfer process, and the bearing assembly is dynamically adjusted by the electromagnet to ensure the positioning accuracy of the suspension shaft 21, without affecting the radial pressure and relative rotation state.
[0036] Test and feeding in parallel: During the transfer of the bearing string, the frontmost bearing gradually approaches the discharge end of the suspension shaft 21 with the transfer, and is pushed off (test completed) when the preset test time is reached; At the same time, the mechanical arm gripper 35 can repeat the feeding step, continuously supplementing new bearings to be tested to the feeding end of the suspension shaft 21 without pausing the test, so that the bearing string always maintains a continuous state, greatly improving the acceleration fatigue test efficiency of the robot joint bearing for new energy vehicle production.
[0037] Inner ring anti-rotation reinforcement: During the transfer process, the limit wheel 33 is always in contact with the shaft surface of the suspension shaft 21, continuously resisting the rotation of the suspension shaft 21 through friction, and then restraining the movement of the inner ring through the friction between the suspension shaft 21 and the inner ring, to avoid the inner ring rotating with the outer ring due to the rotational inertia of the outer ring, ensuring that the test working condition of "outer ring rotation, inner ring non-rotation" is stable and unchanged.
[0038] Further, referring to Figure 8 The embodiment based on the above-mentioned robot joint acceleration fatigue test device also provides a corresponding test method, which comprises the following steps: S1, use the auxiliary assembly to lift the suspension shaft 21 to the center of the two groups of radial electromagnets 22, the radial electromagnets 22 and the axial electromagnets 23 work, the auxiliary assembly resets, and the suspension shaft 21 is suspended in space by the radial and axial magnetic attraction force, and the laser displacement sensor 24 detects the data, and the space is accurately positioned by adjusting the magnetic attraction force at each place; S2, the robot joint bearing is grabbed from the tray by the mechanical arm gripper 35 in the feeding assembly, and then transferred to one end of the suspension shaft 21 and located between the suspension shaft 21 and the axial electromagnet 23 at the end, at which time the bearing inner ring should be aligned with the suspension shaft 21; S3, the linear module 31 drives the U-shaped frame 32 on the sliding block to move, and then the push block 34 abuts against the inner ring of the bearing from one side of the bearing, the linear module 31 continues to act, the mechanical arm gripper 35 is loosened, and finally the bearing is sleeved on the suspension shaft 21 due to being pushed; S4, repeat steps S2 and S3 to sleeve the bearings to be tested on the suspension shaft 21 one by one, and then the roller is lowered by the force applying assembly until the wheel surface abuts against the outer ring of the bearing, and the size of the radial force borne by the bearing is detected by the pressure sensor 16, and then the rotation of the bearing outer ring is driven by the rotation of the roller, thereby simulating the working condition of the bearing in the robot joint under load, and at the same time when the roller is pressed down, the position of the suspension shaft 21 should be adjusted in time by the bearing assembly to avoid the influence of inaccurate positioning of the suspension shaft 21 on the stability of the test; S5, during the test, the U-shaped frame 32 drives the push block 34 to slowly move along the axis direction of the suspension shaft 21, thereby pushing the bearing string to move along the direction of the suspension shaft 21, and the limiting wheel 33 abuts against the shaft surface of the suspension shaft 21, thereby blocking the rotation of the suspension shaft 21 by friction, and by limiting the friction between the suspension shaft 21 and the bearing inner ring after rotation, the inertia of the inner ring rotating with the outer ring is avoided, and after the test time is met, the farthest bearing will be pushed off the suspension shaft 21, and during the test process, the remaining bearings to be tested can be supplemented at any time without pausing the test, thereby improving the test efficiency.
[0039] It should be noted that the above scheme is more suitable for testing materials with low magnetic induction capacity, such as ceramic bearings, due to the existence of magnetic attraction, and accordingly, the material of the suspension shaft 21 should be selected from materials with strong magnetic induction capacity, such as pure iron and low-carbon steel.
[0040] In order to test the bearing material with strong magnetic induction capacity, the embodiment further provides another test method: First, the bearings to be tested are sleeved on the suspension shaft 21 one by one; Second, the auxiliary assembly supports the suspension shaft 21 by the lifting fork 43; Third, the electric cylinder two 44 drives the lifting cross rod 41 to move upwards, and the electric cylinder one 11 drives the roller to move downwards until the roller abuts against the top of the bearing outer ring; Fourth, the roller is rotated by the motor 14, thereby driving the bearing outer ring to rotate, and the downward pressure applied by the electric cylinder one 11 can simulate the working condition of the bearing under radial force, and the size of the force is detected by the pressure sensor 16.
[0041] The test operation for the bearing of high magnetic permeability material is realized without the participation of electromagnet, and the applicability of the test equipment is improved.
[0042] It is to be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0043] While the embodiments of the application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.
Claims
1. A robot joint accelerated fatigue testing device, characterized in that, include: The force application assembly includes an electric cylinder (11) fixedly installed on the top of the cabinet, a wheel frame (12) fixedly connected to the bottom of the telescopic end of the electric cylinder (11), and a pressure roller (13) rotatably connected to the bottom of the wheel frame (12). The load-bearing assembly includes a suspension shaft (21) located in the middle of the cabinet, two sets of radial electromagnets (22) located on both sides of the suspension shaft (21), and two axial electromagnets (23) located at both ends along the axial direction of the suspension shaft (21). Each set of radial electromagnets (22) consists of three units, arranged in a circular array with the axis of the suspension shaft (21) as the center. The feeding assembly includes a linear module (31) fixedly installed below the cabinet, a U-shaped frame (32) fixedly installed on the top of the slider of the linear module (31), two sets of limit wheels (33) rotatably connected to the top of the U-shaped frame (32), each set of limit wheels (33) having four wheels arranged in a symmetrical manner, push blocks (34) fixedly connected to one end of the U-shaped frame (32), and robotic arm grippers (35) fixedly installed on the side of the cabinet.
2. The robot joint accelerated fatigue testing device according to claim 1, characterized in that: The pressure roller (13) is parallel to the suspension shaft (21) and is located directly above the suspension shaft (21). One end of the pressure roller (13) is fixedly connected to a motor (14), and the housing of the motor (14) is fixedly installed at one end of the wheel frame (12).
3. The robot joint accelerated fatigue testing device according to claim 2, characterized in that: A pressure sensor (16) is fixedly installed between the top of the wheel frame (12) and the telescopic end of the electric cylinder (11).
4. The robot joint accelerated fatigue testing device according to claim 3, characterized in that: The top of the wheel frame (12) is fixedly connected to two guide rods (15), and the two guide rods (15) are slidably connected to the inside of the cabinet.
5. The robot joint accelerated fatigue testing device according to claim 4, characterized in that: Both sets of radial electromagnets (22) are fixedly connected to the cabinet, and both axial electromagnets (23) are fixedly connected to the cabinet. A laser displacement sensor (24) is fixedly installed at the center of each radial electromagnet (22) and axial electromagnet (23). The laser beam emitted by the laser displacement sensor (24) should be perpendicular to the surface of the suspension shaft (21).
6. The robot joint accelerated fatigue testing device according to claim 5, characterized in that: The distance between the two sets of limiting wheels (33) is the same as the diameter of the suspension shaft (21). The rotation axis of each limiting wheel (33) is perpendicular to the axis of the suspension shaft (21). When the wheel surface of the limiting wheel (33) abuts against the axial surface of the suspension shaft (21), the friction between the two can prevent the suspension shaft (21) from rotating.
7. The robot joint accelerated fatigue testing device according to claim 6, characterized in that: It also includes auxiliary components, including a lifting crossbar (41) located directly below the suspension shaft (21), springs (42) fixedly connected to the top of the lifting crossbar (41) on both sides, a lifting fork (43) fixedly connected to the top of the springs (42), and an electric cylinder (44) fixedly connected to the center of the bottom of the lifting crossbar (41), the electric cylinder (44) being fixedly installed under the cabinet.
8. The robot joint accelerated fatigue testing device according to claim 7, characterized in that: Guide rods (45) are fixedly connected to both sides of the bottom of the lifting crossbar (41), and the two guide rods (45) are slidably connected to the outside of the cabinet.
9. A test method for accelerated fatigue testing of robot joints, characterized in that: Includes the following steps: S1. Using the auxiliary components, the suspension shaft (21) is lifted to the center of the two sets of radial electromagnets (22). The radial electromagnets (22) and the axial electromagnets (23) work. The auxiliary components are reset. The suspension shaft (21) is suspended in space by the radial and axial magnetic attraction forces formed. The laser displacement sensor (24) detects the data and achieves precise spatial positioning by adjusting the magnetic attraction forces at various points. S2. Use the robotic arm gripper (35) in the feeding assembly to grab the robot joint bearing from the tray and then transfer it to one end of the suspension shaft (21), and place it between the suspension shaft (21) and the axial electromagnet (23) at that end. At this time, the inner ring of the bearing should be aligned with the suspension shaft (21). S3. The linear module (31) drives the U-shaped frame (32) on the slider to move, and then the push block (34) abuts against the inner ring of the bearing from one side of the bearing. The linear module (31) continues to move, and the robotic arm gripper (35) releases in the process. Finally, the bearing is pushed and thus fitted onto the suspension shaft (21). S4. Repeat steps S2 and S3, and install the bearings to be tested one by one on the suspension shaft (21). Then the force application component drives the roller to descend until the wheel surface abuts against the outer ring of the bearing. The pressure sensor (16) detects the magnitude of the radial force on the bearing. Then the roller rotates and drives the outer ring of the bearing to rotate, thereby simulating the working condition of the bearing in the robot joint under load. At the same time, when the roller presses down, the load-bearing component should adjust the position of the suspension shaft (21) in time to avoid the suspension shaft (21) being inaccurately positioned and affecting the test stability. S5. During the test, the U-shaped frame (32) drives the push block (34) slowly along the axis of the suspension shaft (21), thereby pushing the bearing string to move along the direction of the suspension shaft (21) on the suspension shaft (21). At the same time, the limiting wheel (33) abuts against the axial surface of the suspension shaft (21), and the suspension shaft (21) is blocked from rotating by friction. By limiting the friction between the suspension shaft (21) after rotation and the inner ring of the bearing, the inner ring is prevented from rotating with the outer ring due to inertia. After the test time is satisfied, the bearing at the farthest point will be pushed off the suspension shaft (21). During the test, by repeating steps S2 and S3, the remaining bearings to be tested can be added at any time without pausing the test, thereby improving the test efficiency.