A device and method for evaluating anti-stiction fatigue performance of planetary gears

Abstract

This invention relates to a device and method for evaluating the fretting fatigue performance of planetary gears, belonging to the field of planetary gear technology. The device includes: a testing platform, with the top of the platform mounted on top; a first fretting assembly in which the contact position between a contact rod and the gear teeth is adjusted by a rotating rod. During the rotation of the planetary gear teeth, the contact rod reciprocates and continuously contacts the same position on different teeth along the rotation path, providing excitation force for testing. This facilitates providing comprehensive excitation force to the planetary gear. In the second fretting mechanism, a fixed rod provides excitation force to the main shaft of the sun gear from different angles, and two sliding plates can provide excitation force to the sun gear shaft from different directions as needed for testing, more realistically simulating the vibration environment in working conditions. The fretting mechanism facilitates comprehensive detection of the fretting motion of the planetary gears, improving the accuracy of the fretting fatigue performance evaluation of planetary gears.

Description

Technical Field

[0001] This invention relates to the field of planetary gear technology, and in particular to a device and method for evaluating the anti-fretting fatigue performance of planetary gears. Background Technology

[0002] In planetary gear transmission systems, under long-term and complex alternating loads, fretting is prone to occur at the interference fit between the outer ring of the bearing and the inner bore of the planetary gear. Fretting refers to the relative sliding of a few micrometers to tens of micrometers between the contacting surfaces. Fretting can lead to fretting fatigue between the contact surfaces, significantly reducing the service life of the planetary gear system. In severe cases, it can cause cracks to develop from the inside out of the planetary gear, resulting in structural fatigue failure. Therefore, evaluating the fretting fatigue resistance of planetary gears is crucial.

[0003] Currently, the common structure for evaluating the fretting fatigue resistance of planetary gears in existing technologies is to use a vibrator to apply excitation force to the planetary gears and then evaluate their fretting fatigue resistance. However, during testing, the contact block that generates the excitation force to the planetary gears is fixed, which cannot provide a comprehensive excitation force to the planetary gears for fretting performance testing. Therefore, it is impossible to conduct a comprehensive test on the planetary gears, which will affect the accuracy of the fretting fatigue test. Summary of the Invention

[0004] Therefore, it is necessary to provide a device and method for evaluating the fretting fatigue performance of planetary gears, which addresses the problem that the contact block that generates the excitation force to the planetary gears during testing is fixed and cannot provide a comprehensive excitation force to the planetary gears for performance testing. As a result, the planetary gears cannot be fully tested, which affects the accuracy of the fretting fatigue test.

[0005] Includes: a testing platform, the top of which is equipped with a motor and a mounting frame;

[0006] The micro-motion mechanism includes three first micro-motion components and a second micro-motion component installed on the top of the detection stage, and a fixing ring is fixedly connected to the top of the detection stage;

[0007] The first micro-motion component includes a first vibrator fixedly connected to the surface of a fixed ring. A telescopic rod is fixedly connected to the output end of the first vibrator. A rotating rod is rotatably connected to the end of the telescopic rod away from the first vibrator. A rectangular frame is fixedly connected to the end of the rotating rod away from the telescopic rod. A moving rod is slidably connected to the inner wall of the rectangular frame. A spring is fixedly connected between one end of the moving rod and the inner wall of the rectangular frame. A contact rod is fixedly connected to the end of the moving rod away from the spring through the rectangular frame.

[0008] The frame mechanism includes a mounting plate fixedly installed on the testing table and two mounting frames. A test frame is provided at the top of the mounting plate, and an angular displacement sensor is provided on the test frame. The angular displacement sensor is used to detect the micro-momentum of the planetary gear.

[0009] Both of the mounting brackets are fixedly mounted with electric push rods at their top ends, and the telescopic ends of the electric push rods are fixedly connected with locking plates.

[0010] The differential measuring device, which was originally intended to be installed at position 600 in the overall drawing, has been moved out of the overall drawing due to obstruction of other parts, and will be discussed below. Figure 13 Specifically, the differential measurement device includes an L-bracket fixedly connected to the top of the testing platform, two miniature eddy current displacement sensors, two reference rings, and a signal acquisition module. Both miniature eddy current displacement sensors are mounted on the L-bracket. One of the reference rings is mounted on the outer edge of the bearing of the planetary gear, and the other reference ring is mounted on the side of the gear to be tested. The detection end of the miniature eddy current displacement sensor is aligned with the surface of the reference ring.

[0011] A power-conducting wire, which is directly connected to the inside of the insulating support;

[0012] A bracket assembly, comprising a first bracket, a second bracket, and a third bracket, is securely connected to a fixing ring and a planetary gear.

[0013] A rolling bearing is mounted on a fixed ring, with the portion containing the first micro-motion component exposed outside the rolling bearing and the other half confined inside the rolling bearing, so that the first micro-motion component rotates synchronously with the planetary gear, and the first micro-motion component is continuously energized.

[0014] An insulating bracket has a groove inside its mating surface with the rolling bearing. An electrical wire board is placed in the groove. The electrical wire board rubs against the rolling bearing, causing current to flow through the rolling bearing and continuously powering the first micro-motion component.

[0015] In one embodiment, the first micro-motion assembly further includes a limiting ring fixedly connected to one end of the surface of the telescopic rod. The surface of the rotating rod is rotatably connected to the inner wall of the limiting ring, and a bolt is threaded onto the inner wall of the limiting ring. One end of the bolt is rotatably connected to a clamping plate. This ensures that the angle of the rotating rod to the contact rod can be adjusted while the rotated rod is fixed, thus ensuring the stability of the device operation.

[0016] In one embodiment, the second micro-motion component includes a second vibrator. A fixed rod is fixedly connected to the output end of the second vibrator. A mounting rod is fixedly connected to the top of the detection stage. A sphere is fixedly connected to the top of the mounting rod. The end of the fixed rod away from the second vibrator is slidably connected to the inner wall of the sphere. A contact plate is fixedly connected to the surface of the sphere. Two sliding plates are slidably connected to the inner wall of the contact plate. This design facilitates the application of excitation force to the planetary gears via the sun gear's shaft for detection. The rotation of the second vibrator and the fixed rod allows the fixed rod to provide excitation force to the sun gear's shaft from different angles. Furthermore, the two sliding plates allow the plates to contact the surface of the sun gear's shaft from different directions as needed for detection, thus providing excitation force to the sun gear's shaft from various directions.

[0017] In one embodiment, the second micro-motion assembly further includes a motor rotatably connected to the top of the testing stage. The output shaft of the motor is fixedly connected to a connecting rod, the top end of which is fixedly connected to the bottom end of the second vibrator. This facilitates driving the second vibrator and the fixed rod to rotate along the sphere.

[0018] In one embodiment, a limiting plate is fixedly connected to the surface of the mounting rod, and the surface of the connecting rod is slidably connected to the inner wall of the limiting plate. The limiting plate is in the shape of a half-circle, and the center of the limiting plate coincides with the center of the sphere. This facilitates limiting the movement path of the connecting rod and supports the second vibrator, thereby enhancing the operational stability of the second vibrator.

[0019] In one embodiment, a fastening screw is threaded onto one side of the inner wall of the slide plate, and the surface of the fastening screw is slidably connected to the inner wall of the contact plate. This facilitates limiting the sliding of the slide plate and ensures its stable operation.

[0020] In one embodiment, a locking rod is slidably connected to the inner wall of the limiting ring, and a matching locking hole is provided on the inner wall of the bolt knob. This facilitates limiting the tightened bolt and enhances the stability of the rotating rod during operation.

[0021] In one embodiment, the surface of the abutment plate is curved into an arc shape, and an abutment pad is fixedly connected to the inner surface of the abutment plate. This helps to increase the friction between the abutment plate and the surface of the rotating rod.

[0022] In one embodiment, the vertical cross-section of the contact rod is elliptical. This prevents the contact rod from fully engaging between two adjacent teeth, avoiding jamming between them and ensuring that the teeth can properly push the contact rod during rotation.

[0023] In one embodiment, the overall shape of the contact plate is a half-circle, and the two sliding plates are symmetrical about the center of the contact plate. This facilitates better contact with the surface of the sun gear.

[0024] Beneficial effects

[0025] 1. By rotating the rotating rod, the tilt angle of the contact rod can be adjusted according to the testing needs, thereby adjusting the contact position between the contact rod and the gear teeth. This facilitates better contact between the contact rod and the gear teeth. Under the action of the first exciter, the contact rod generates excitation force, which is applied to the planetary gear through the gear teeth for testing the planetary gear's anti-fretting fatigue performance. During the test, the planetary gear rotates, and under the action of the contact rod shape and spring, the contact rod reciprocates during the rotation of the planetary gear teeth, continuously contacting the same position of each gear tooth on the rotation path and providing excitation force. This allows for the collection of micro-momentum data of the planetary gear under multiple working conditions, thereby using the data to evaluate the fatigue performance of the planetary gear and improving the accuracy of the planetary gear fretting fatigue test performance evaluation.

[0026] 2. The aforementioned second micro-motion mechanism, through the second vibrator, fixed rod, ball, and contact plate, facilitates the application of excitation force to the planetary gears via the sun gear's main shaft for testing. The rotation of the second vibrator and fixed rod allows the fixed rod to provide excitation force to the sun gear's main shaft from different angles. Furthermore, the two sliding plates allow the plates to contact the sun gear's shaft surface from different directions as needed for testing, thus providing excitation force to the sun gear's shaft from various directions. This more realistically simulates the vibration environment in actual working conditions and improves the accuracy of planetary gear micro-motion fatigue test performance evaluation. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the planetary gear and the fixing frame of the present invention;

[0030] Figure 3 This is a schematic diagram of the micro-motion mechanism and planetary gear of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the first micro-motion component of the present invention;

[0032] Figure 5 This is a cross-sectional view of the limiting ring and rectangular frame of the present invention;

[0033] Figure 6 This is a cross-sectional view of the telescopic rod of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the second micro-motion component of the present invention;

[0035] Figure 8 This is an exploded view of the second exciter and connecting rod of the present invention;

[0036] Figure 9 This is a schematic diagram of the micro-motion mechanism, planetary gear, and frame mechanism of the present invention;

[0037] Figure 10 This is a schematic diagram showing the connection of the energized wire, bracket assembly, rolling bearing, and insulating bracket of the present invention.

[0038] Figure 11 This is a schematic diagram of the planetary gear structure tested in this invention;

[0039] Figure 12 This is a schematic diagram of the planetary gear and frame mechanism of the present invention;

[0040] Figure 13 This is a schematic diagram of the overall structure of the differential measuring device of the present invention.

[0041] Figure label:

[0042] 100. Testing table; 200. Motor; 300. Fixture; 400. Micro-motion mechanism; 410. First micro-motion assembly; 411. First vibrator; 412. Telescopic rod; 413. Rotating rod; 414. Rectangular frame; 415. Moving rod; 416. Spring; 417. Contact rod; 418. Limiting ring; 419. Bolt; 4191. Clamping plate; 4192. Locking rod; 420. Second micro-motion assembly; 421. Mounting rod; 422. Ball; 423. Contact plate; 424. Slide plate; 4241. Fastening screw; 425. Limiting plate; 426. Second vibrator; 427. Fixture 428. Fixed rod; 429. Electric motor; 430. Connecting rod; 500. Fixing ring; 510. Frame mechanism; 511. Mounting plate; 512. Test frame; 513. Angular displacement sensor; 520. Mounting bracket; 521. Electric push rod; 522. Locking plate; 600. Differential measuring device; 610. L-bracket; 620. Miniature eddy current displacement sensor; 630. Reference ring; 640. Signal acquisition module; 700. Power-carrying wire; 800. Support assembly; 810. First support; 820. Second support; 830. Third support; 900. Rolling bearing; 1000. Insulating support. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this specification are for illustrative purposes only and do not represent the only possible implementation.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0048] The following is combined with Figures 1-13 The present invention describes the apparatus and method for evaluating the anti-fretting fatigue performance of planetary gears.

[0049] In one embodiment, a planetary gear anti-fretting fatigue performance evaluation device includes: a test table 100, with a motor 200 and a fixing frame 300 mounted on the top of the test table 100.

[0050] The micro-motion mechanism 400 includes three first micro-motion components 410 and a second micro-motion component 420 installed on the top of the detection table 100. A fixing ring 430 is fixedly connected to the top of the detection table 100.

[0051] The first micro-motion component 410 includes a first exciter 411 fixedly connected to the surface of the fixed ring 430. A telescopic rod 412 is fixedly connected to the output end of the first exciter 411. A rotating rod 413 is rotatably connected to the end of the telescopic rod 412 away from the first exciter 411. A rectangular frame 414 is fixedly connected to the end of the rotating rod 413 away from the telescopic rod 412. A moving rod 415 is slidably connected to the inner wall of the rectangular frame 414. A spring 416 is fixedly connected between one end of the moving rod 415 and the inner wall of the rectangular frame 414. A contact rod 417 is fixedly connected to the end of the moving rod 415 away from the spring 416 through the rectangular frame 414.

[0052] The frame mechanism 500 includes a mounting plate 510 fixedly installed on the testing table 100 and two mounting frames 520. A test frame 511 is provided on the top of the mounting plate 510, and an angular displacement sensor 512 is provided on the test frame 511. The angular displacement sensor 512 is used to detect the micro-momentum of the planetary gear.

[0053] Electric push rods 521 are fixedly installed on the top of both mounting brackets 520, and locking plates 522 are fixedly connected to the telescopic ends of the electric push rods 521.

[0054] The differential measuring device 600, which was originally intended to be installed at the overall drawing 600, has been moved out of the overall drawing due to obstruction of other parts, and will be described below. Figure 13 Specifically shown, the differential measurement device 600 includes an L-bracket 610 fixedly connected to the top of the test stage 100, two miniature eddy current displacement sensors 620, two reference rings 630, and a signal acquisition module 640. Both miniature eddy current displacement sensors 620 are mounted on the L-bracket 610. One reference ring 630 is mounted on the outer edge of the bearing of the planetary gear, and the other reference ring 630 is mounted on the side of the gear to be tested. The detection end of the miniature eddy current displacement sensor 620 is aligned with the surface of the reference ring 630.

[0055] The power-conducting wire 700 is directly connected to the inside of the insulating bracket 1000;

[0056] The bracket assembly 800 includes a first bracket 810, a second bracket 820 and a third bracket 830, which are fastened to the retaining ring 430 and the planetary gear.

[0057] A rolling bearing 900 is mounted on a fixed ring 430, with the first micro-motion component 410 partially exposed outside the rolling bearing 900 and the other half confined inside the rolling bearing 900, so that the first micro-motion component 410 rotates synchronously with the planetary gear, and the first micro-motion component 410 is continuously energized.

[0058] The insulating bracket 1000 has a groove inside the mating surface with the rolling bearing 900. An electric wire board is placed in the groove. The electric wire board rubs against the rolling bearing 900, so that the current is input to the first micro-motion component (410) through the rolling bearing 900 to continuously supply power.

[0059] In this embodiment, a new power-carrying wire 700 is added. Its function is as follows: the power-carrying wire 700 is directly connected to the insulating bracket 1000. The insulating bracket 1000 has a groove inside to place the wire board, so that it is energized. The wire board at the groove continuously rubs against the rolling bearing 900. The current is input to the first micro-motion component 410 through the rolling bearing 900, which in fact provides continuous power to the vibrator.

[0060] In this embodiment, the newly added first bracket 810, second bracket 820 and third bracket 830 are used to weld the three brackets between the fixed ring 430 and the planetary gear, so that the fixed ring 430 is connected to the planetary gear, so that when the planetary gear rotates, the ring rotates through the brackets, and the rotation of the ring drives the rolling bearing 900, so that the vibrator on the ring rotates synchronously with the planetary gear and continuously outputs excitation.

[0061] In this embodiment, a rolling bearing 900 is added, which is tightly fitted to the insulating bracket 1000 and fixed on the insulating bracket 1000. Its function is to drive the fixed ring 430 to rotate when the bracket is under force, so as to achieve synchronous rotation with the planetary gear.

[0062] It should be noted that the electric actuator 521 is a DYT series electro-hydraulic actuator with its own pressure self-locking mechanism. After the power is cut off, the position of the piston rod remains unchanged, ensuring that it can remain stable after locking the planetary gear and will not loosen.

[0063] The 512 angular displacement sensor is a non-contact angular displacement sensor. The Novotechnik RSC2831 series industrial grade sensor can be selected. During testing, the sensor ring is installed separately from the body. The key steps are to securely mount the magnetic ring onto the gear shaft and rigidly fix the sensor probe to a nearby stationary component, while precisely ensuring the specified air gap and good alignment between the two. This design is precisely to meet the requirements of high-precision, non-contact angle measurement within complex mechanical structures such as planetary gearboxes, measuring the corresponding fretting distance and evaluating the planetary gear's resistance to fretting fatigue based on the read fretting distance data.

[0064] The exciter can be a JZQ-70 / 700N electric modal exciter, and the excitation force can be adjusted according to the test requirements.

[0065] The telescopic rod 412 includes a round rod and a sliding rod. One end of the round rod is fixedly connected to the output end of the first vibrator 411, and the end of the sliding rod away from the round rod is rotatably connected to the rotating rod 413. A locking screw is threaded to one end of the inner wall of the round rod, and a threaded hole is provided on one side of the sliding rod. During the detection of the planetary gear by the first micro-motion component 410, the round rod and the sliding rod can be fixed by using the locking screw and the threaded hole. The surface of the sliding rod is slidably connected to the inner wall of the round rod. A sliding groove matching the sliding rod is provided on the inner wall of the round rod. The vertical cross section of the sliding rod is rectangular, so the sliding rod remains stable when the rotating rod 413 is rotated.

[0066] In the initial state, the telescopic rods 412 in the three first micro-motion components 410 are in a retracted state, and at this time the telescopic rods 412 do not affect the placement of the planetary gears.

[0067] After the planetary carrier and fixed frame 300 and the sun gear and motor 200 output shaft are installed, the contact rods 417 in the three first micro-motion components 410 are pulled to move into the planetary gears, so that the contact rod 417 in one of the first micro-motion components 410 contacts the surface of the planet gear teeth, the contact rod 417 in another of the first micro-motion components 410 contacts the surface of the sun gear teeth, and the contact rod 417 in yet another of the first micro-motion components 410 contacts the surface of the gear ring teeth. After contact, the rotatable rod 413 drives the corresponding contact rod 417 to rotate through the rectangular frame 414 and the moving rod 415, thereby adjusting the contact position between the contact rod 417 and the corresponding gear teeth.

[0068] It should be noted that when the contact rod 417 is pressed and moved by the corresponding gear teeth, the moving rod 415 connected to the contact rod 417 moves in the same direction as the moving rod 417 within the rectangular frame 414.

[0069] Once one planetary gear has been tested, the planet carrier can be removed and the position of the planetary gear adjusted so that the position of the other planetary gear corresponds to that of one of the first micro-motion components 410. This allows one of the first micro-motion components 410 to apply micro-power to the other planetary gear and perform testing. All three planetary gears can be tested in this manner.

[0070] like Figure 3 , Figure 4 and Figure 5 As shown, the first micro-motion assembly 410 also includes a limiting ring 418 fixedly connected to one end of the surface of the telescopic rod 412. The surface of the rotating rod 413 is rotatably connected to the inner wall of the limiting ring 418. A bolt 419 is threadedly connected to the inner wall of the limiting ring 418, and a clamping plate 4191 is rotatably connected to one end of the bolt 419. A locking rod 4192 is slidably connected to the inner wall of the limiting ring 418, and a matching locking hole is provided on the inner wall of the bolt 419 knob. The surface of the clamping plate 4191 is curved into an arc shape, and a clamping pad is fixedly connected to the inner surface of the clamping plate 4191.

[0071] In this embodiment, the curvature of the inner surface of the clamping plate 4191 matches the curvature of the surface of the rotating rod 413. In the initial state, when the bolt 419 is tightened, the clamping plate 4191 drives the clamping pad to press against the surface of the rotating rod 413, thereby fixing the rotating rod 413 and keeping it stable. After the bolt 419 is tightened, the locking hole of the bolt 419 knob coincides with the mounting hole of the locking rod 4192 on the surface of the limiting ring 418. The locking rod 4192 penetrates longitudinally through the locking hole of the bolt 419 knob and the mounting hole of the limiting ring 418. After penetrating longitudinally, the locking rod 4192 is located at the eccentric position of the bolt 419, thereby limiting the bolt 419.

[0072] When it is necessary to rotate the rotating rod 413, simply release the fixing of the rotating rod 413, and then fix it again after the rotating rod 413 has been rotated.

[0073] The abutment pad is a rubber component that increases the friction between the abutment plate 4191 and the surface of the rotating rod 413.

[0074] like Figure 2 , Figure 7 and Figure 8As shown, the second micro-motion assembly 420 includes a second vibrator 426. A fixing rod 427 is fixedly connected to the output end of the second vibrator 426. A mounting rod 421 is fixedly connected to the top of the detection platform 100. A sphere 422 is fixedly connected to the top of the mounting rod 421. The end of the fixing rod 427 away from the second vibrator 426 is slidably connected to the inner wall of the sphere 422. A contact plate 423 is fixedly connected to the surface of the sphere 422. Two sliding plates 424 are slidably connected to the inner wall of the contact plate 423. The second micro-motion assembly 420 also includes a motor 428 rotatably connected to the top of the detection platform 100. A connecting rod 429 is fixedly connected to the output shaft of the motor 428. The top of the connecting rod 429 is fixedly connected to the bottom end of the second vibrator 426. The overall shape of the contact plate 423 is a half-circle, and the two sliding plates 424 are symmetrical about the center of the contact plate 423.

[0075] In this embodiment, after the planetary gear is installed on the testing platform 100, the inner surface of the contact plate 423 is in contact with the rotation axis of the sun gear in the planetary gear.

[0076] When the motor 428 is started by the controller, the output shaft of the motor 428 can drive the second vibrator 426 to rotate from zero degrees to 180 degrees through the connecting rod 429. The end of the fixed rod 427 away from the second vibrator 426 is bent into a spherical shape. During the rotation of the fixed rod 427 driven by the second vibrator 426, the end of the fixed rod 427 away from the second vibrator 426 is always in contact with the sphere 422.

[0077] like Figure 8 As shown, a limiting plate 425 is fixedly connected to the surface of the mounting rod 421, and the surface of the connecting rod 429 is slidably connected to the inner wall of the limiting plate 425. The overall shape of the limiting plate 425 is a half-circle ring, and the center of the limiting plate 425 coincides with the center of the sphere 422.

[0078] In this embodiment, a limiting groove is formed on the inner wall of the limiting plate 425. The shape of the limiting groove matches the rotational movement path of the connecting rod 429, thereby limiting the movement of the connecting rod 429 and supporting the second vibrator 426 during its movement.

[0079] like Figure 8 As shown, a fastening screw 4241 is threadedly connected to one side of the inner wall of the slide plate 424, and the surface of the fastening screw 4241 is slidably connected to the inner wall of the contact plate 423.

[0080] In this embodiment, the operator can pull the slide plate 424 out of the contact plate 423 by fastening the screw 4241. After the slide plate 424 has slid into place, the fastening screw 4241 can be tightened so that the knob of the fastening screw 4241 abuts against one end of the contact plate 423, thereby fixing the position of the slide plate 424. After the slide plate 424 slides out of the contact plate 423, the inner surface of the slide plate 424 is still in contact with the surface of the sun gear shaft in the planetary gear.

[0081] One end of the contact plate 423 has an arc-shaped groove, and the surface of the fastening screw 4241 fits against the inner wall of the arc-shaped groove. The curvature of the arc-shaped groove is the same as the curvature of the contact plate 423.

[0082] like Figure 5 As shown, the vertical cross-section of the contact rod 417 is elliptical.

[0083] In this embodiment, the maximum diameter of the contact rod 417 is greater than the maximum distance between two adjacent teeth. Therefore, during the rotation of the teeth, the contact rod 417 cannot fully enter between two adjacent teeth, thus preventing the contact rod 417 from getting stuck between two adjacent teeth. As a result, when the contact position of the contact rod 417 and the corresponding tooth is adjusted, the teeth can normally push the contact rod 417 to move and compress the spring 416 during the rotation of the teeth. After the compression is released, the spring 416 resets the contact rod 417. The contact rod 417 will always contact the same position with different teeth.

[0084] Test Description: Testing of planetary gears under multiple operating conditions:

[0085] Example 1:

[0086] a: Testing the fretting fatigue resistance of planetary gears in the absence of external excitation force:

[0087] The shaft of the sun gear is directly connected to the output shaft of the motor 200 using a coupling. The motor 200 drives the planetary gear to rotate freely. After running for a preset test time, the micro-motion distance output by the angular displacement sensor 512 is read, and the anti-fretting fatigue performance of the planetary gear is evaluated based on the read micro-motion distance data.

[0088] b: Lock the outer ring of the planetary gear and test its resistance to fretting fatigue:

[0089] The electric push rod 521 is activated, which drives the locking plate 522 to lock the outer edge of the planetary gear ring. Then, the shaft of the sun gear is directly connected to the output shaft of the motor 200 using a coupling. At this time, when the motor 200 rotates, the gear ring remains stationary, and the sun gear rotates under the drive of the motor 200. Under the meshing action, the three planetary gears revolve. After running for the preset test time, the micro-motion distance output by the angular displacement sensor 512 is read, and the anti-fretting fatigue performance of the planetary gear is evaluated based on the read micro-motion distance data.

[0090] c: For the two test conditions a and b above, the second micro-motion component 420 cooperates with each other:

[0091] When the planetary gear is tested by applying micro-power using the second micro-motion component 420, the second vibrator 426 is started by the controller. At this time, the contact plate 423 will generate excitation force through the fixed rod 427 and the ball 422. The excitation force acts on the sun gear spindle through the contact plate 423. The motor 428 is started by the controller, which causes the connecting rod 429 to drive the second vibrator 426 and the fixed rod 427 to rotate. This allows the fixed rod 427 to provide excitation force to the sun gear spindle from different angles. During the test, the slide plate 424 can be rotated to contact the surface of the sun gear spindle from different directions. During the test, the slide plate 424 can provide excitation force to the sun gear spindle from different directions.

[0092] Combined with a and b respectively, the angular displacement sensor 512 reads the corresponding micro-motion distance data;

[0093] d: Regarding process b, the anti-fretting fatigue performance of the planetary gear is tested by combining the first micro-motion component 410 and the second micro-motion component 420. The locked state is shown in the appendix. Figure 9 ;

[0094] The contact rod 417 in the first micro-motion assembly 410 contacts the surface of the gear ring. After contact, the rotating rod 413 is rotated to drive the corresponding contact rod 417 to rotate and adjust the contact position between the contact rod 417 and the corresponding gear ring. After the adjustment is completed, the first exciter 411 in the first micro-motion assembly 410 is started by the controller. The contact rod 417 generates an excitation force through the telescopic rod 412, the rotating rod 413, the rectangular frame 414 and the moving rod 415. The excitation force acts on the planetary gear through the contact position between the contact rod 417 and the gear teeth.

[0095] Combined with the second micro-motion component 420 in c, the motor 200 drives the sun gear to rotate, the gear ring is locked in a non-rotating state, the planetary gear revolves, the micro-motion distance output by the angular displacement sensor 512 is read, and the anti-micro-motion fatigue performance of the planetary gear is evaluated based on the read micro-motion distance data;

[0096] Example 2:

[0097] After completing the connection between the planetary carrier and the fixed frame 300, the sun gear is directly connected to the output shaft of the motor 200. In this scenario, the planetary gear rotates, the sun gear rotates, and the gear ring rotates.

[0098] Operating condition 1: The first micro-motion component 410 and the second micro-motion component 420 are not connected. The motor 200 is started, and the motor 200 drives the planetary gear to rotate. At this time, the planetary gear is in a state without external force.

[0099] After running for the preset test time, the micro-motion distance output by the angular displacement sensor 512 is read, and the anti-fretting fatigue performance of the planetary gear is evaluated based on the read micro-motion distance data;

[0100] Operating Condition 2: The second micro-motion component 420 applies excitation force to the sun gear shaft. After running for the preset test time, the micro-motion distance output by the angular displacement sensor 512 is read, and the anti-fretting fatigue performance of the planetary gear is evaluated based on the read micro-motion distance data.

[0101] Working condition 3: Using three sets of first micro-motion components 410, the excitation force is simultaneously applied to the sun gear, star gear and gear ring to obtain the corresponding micro-motion distance data;

[0102] The excitation force is applied by two sets of first micro-motion components 410: the excitation force is applied by the sun gear and the star gear, the excitation force is applied by the sun gear and the gear ring, and the excitation force is applied by the star gear and the gear ring, thereby obtaining the corresponding micro-motion distance data;

[0103] Using a set of first micro-motion components 410 to apply excitation force, there are three cases: 1. Excitation force is applied by the sun gear; 2. Excitation force is applied by the star gear; 3. Excitation force is applied by the gear ring, and the corresponding micro-motion distance data is obtained.

[0104] By using the second micro-motion component 420 in conjunction with the test in working condition three, the corresponding micro-motion distance data can be obtained;

[0105] As can be seen from the above, the fretting distance of planetary gears under various working conditions can be tested. The tested data can be compared with qualified fretting data to complete the evaluation of the fretting fatigue performance of planetary gears.

[0106] Data acquisition instructions: First, install the miniature eddy current displacement sensor 620 and the reference ring 630. Fix the L-bracket 610 on the test stage 100 and keep it relatively stationary. Install the two reference rings 630 on the gear to be tested. Install one reference ring 630 on the outer hub of the gear to be tested and install the other reference ring 630 on the corresponding position on the outer edge of the bearing. Align the detection ends of the two miniature eddy current displacement sensors 620 with the reference rings 630.

[0107] In conjunction with the above detection process, the signal acquisition module 640 is used to acquire data;

[0108] One of the miniature eddy current displacement sensors, 620, has a value of χ;

[0109] Another miniature eddy current displacement sensor, 620, has a value of β;

[0110] Then calculate the difference:

[0111] γ = χ - β;

[0112] γ is the pure micro-motion relative displacement value, thus realizing the measurement of the micro-motion value.

[0113] It should be noted that a vibrator is a device attached to machinery and equipment to generate excitation force, causing the excited object to obtain a certain form and magnitude of vibration, thereby conducting vibration and strength tests on the object. The motor, electric motor, vibrator, and detector mentioned above are all devices with relatively mature existing technologies. Specific models can be selected according to actual needs. At the same time, the motor, electric motor, and vibrator can be powered by mains power. During testing, the motor, electric motor, and vibrator will not rotate axially, so there will be no wiring entanglement. When conducting tests under various working conditions, there is no need to reconnect the wiring, which will not be elaborated here.

[0114] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A device for evaluating the fretting fatigue performance of planetary gears, characterized in that, include: A testing table (100) is provided with a motor (200) and a fixing frame (300) installed on its top. The micro-motion mechanism (400) includes three first micro-motion components (410) and a second micro-motion component (420) installed on the top of the detection stage (100). A fixing ring (430) is fixedly connected to the top of the detection stage (100). The first micro-motion component (410) includes a first exciter (411) fixedly connected to the surface of a fixed ring (430). A telescopic rod (412) is fixedly connected to the output end of the first exciter (411). A rotating rod (413) is rotatably connected to the end of the telescopic rod (412) away from the first exciter (411). A rectangular frame (414) is fixedly connected to the end of the rotating rod (413) away from the telescopic rod (412). A moving rod (415) is slidably connected to the inner wall of the rectangular frame (414). A spring (416) is fixedly connected between one end of the moving rod (415) and the inner wall of the rectangular frame (414). The end of the moving rod (415) away from the spring (416) passes through the rectangular frame (414) and is fixedly connected to a contact rod (417). The frame mechanism (500) includes a mounting plate (510) fixedly installed on the testing table (100) and two mounting frames (520). A test frame (511) is provided at the top of the mounting plate (510). An angular displacement sensor (512) is provided on the test frame (511). The angular displacement sensor (512) is used to detect the micro-momentum of the planetary gear. Electric push rods (521) are fixedly installed at the top of both mounting brackets (520), and locking plates (522) are fixedly connected to the telescopic ends of the electric push rods (521). A differential measuring device (600) includes an L-bracket (610) fixedly connected to the top of a test bench (100), two miniature eddy current displacement sensors (620), two reference rings (630), and a signal acquisition module (640). The two miniature eddy current displacement sensors (620) are both mounted on the L-bracket (610). One of the reference rings (630) is mounted on the outer edge of the bearing of the planetary gear, and the other reference ring (630) is mounted on the side of the gear to be tested. The detection end of the miniature eddy current displacement sensor (620) is aligned with the surface of the reference ring (630). A power-conducting wire (700) is directly connected to the interior of an insulating support (1000); A bracket assembly (800) includes a first bracket (810), a second bracket (820) and a third bracket (830), which are fastened to a retaining ring (430) and a planetary gear; A rolling bearing (900) is mounted on a fixed ring (430) such that the portion of the first micro-motion component (410) is exposed outside the rolling bearing (900), while the other half is confined inside the rolling bearing (900), so that the first micro-motion component (410) rotates synchronously with the planetary gear, and the first micro-motion component (410) is continuously excited. An insulating bracket (1000) has a groove inside the mating surface with the rolling bearing (900). An electrical wire board is placed in the groove. The electrical wire board rubs against the rolling bearing (900), so that the current is input to the first micro-motion component (410) through the rolling bearing (900) to continuously power the device.

2. The planetary gear anti-fretting fatigue performance evaluation device according to claim 1, characterized in that, The first micro-motion component (410) also includes a limiting ring (418) fixedly connected to one end of the surface of the telescopic rod (412). The surface of the rotating rod (413) is rotatably connected to the inner wall of the limiting ring (418). The inner wall of the limiting ring (418) is threaded with a bolt (419), and one end of the bolt (419) is rotatably connected to a clamping plate (4191).

3. The planetary gear anti-fretting fatigue performance evaluation device according to claim 1, characterized in that, The second micro-motion component (420) includes a second vibrator (426), the output end of the second vibrator (426) is fixedly connected to a fixing rod (427), the top end of the detection stage (100) is fixedly connected to an installation rod (421), the top end of the installation rod (421) is fixedly connected to a ball (422), the end of the fixing rod (427) away from the second vibrator (426) is slidably connected to the inner wall of the ball (422), the surface of the ball (422) is fixedly connected to a contact plate (423), and the inner wall of the contact plate (423) is slidably connected to two sliding plates (424).

4. The planetary gear anti-fretting fatigue performance evaluation device according to claim 3, characterized in that, The second micro-motion assembly (420) also includes a motor (428) rotatably connected to the top of the detection stage (100), the output shaft of the motor (428) is fixedly connected to a connecting rod (429), and the top end of the connecting rod (429) is fixedly connected to the bottom end of the second vibrator (426).

5. The planetary gear anti-fretting fatigue performance evaluation device according to claim 4, characterized in that, The surface of the mounting rod (421) is fixedly connected to the limiting plate (425), the surface of the connecting rod (429) is slidably connected to the inner wall of the limiting plate (425), the overall shape of the limiting plate (425) is a half-circle ring, and the center of the limiting plate (425) coincides with the center of the sphere (422).

6. The planetary gear anti-fretting fatigue performance evaluation device according to claim 3, characterized in that, The inner wall of the slide plate (424) is threaded with a fastening screw (4241), and the surface of the fastening screw (4241) is slidably connected to the inner wall of the contact plate (423).

7. The planetary gear anti-fretting fatigue performance evaluation device according to claim 2, characterized in that, The inner wall of the limiting ring (418) is slidably connected to a locking rod (4192), and the inner wall of the bolt (419) knob is provided with a matching locking hole.

8. The planetary gear anti-fretting fatigue performance evaluation device according to claim 2, characterized in that, The surface of the abutment plate (4191) is curved into an arc shape, and an abutment pad is fixedly connected to the inner surface of the abutment plate (4191).

9. The planetary gear anti-fretting fatigue performance evaluation device according to claim 1, characterized in that, The vertical cross-section of the contact rod (417) is elliptical.

10. The planetary gear anti-fretting fatigue performance evaluation device according to claim 3, characterized in that, The overall shape of the contact plate (423) is a half-circle, and the two sliding plates (424) are symmetrical about the center of the contact plate (423).

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