Variable center distance gear tester for simulating vacuum environment

Abstract

The application discloses a variable center distance gear testing machine for simulating a vacuum environment and relates to the technical field of mechanical transmission. The variable center distance gear testing machine comprises a vacuum chamber, a testing machine body, a center distance adjusting platform and sensors. The vacuum chamber is capable of forming a vacuum environment. The testing machine body is arranged in the vacuum chamber and comprises a driving gear shaft and a driven gear shaft. The driving gear shaft and the driven gear shaft are respectively used for connecting a driving gear and a driven gear. The driving gear shaft is in transmission connection with a testing machine driving shaft. The testing machine driving shaft is externally connected with a driving device. The center distance adjusting platform is arranged at the bottom of the driven gear shaft and can drive the driven gear shaft to move close to or away from the driving gear shaft. The sensors are respectively arranged at the testing machine body and are used for measuring torque, vibration and noise signals in a testing process. The variable center distance gear testing machine can change the center distance between gears in a testing process of simulating a vacuum environment, and the testing range is increased.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission technology, and in particular to a variable center distance gear testing machine for simulating a vacuum environment. Background Technology

[0002] Space gears, as commonly used speed reduction, torque amplification, and power conversion mechanisms, are characterized by their compact structure and high power density, and are widely used in spacecraft camera focusing mechanisms, scanning mechanisms, and robotic arms. Space gears are typically made of metal, but metal materials cannot form a wear-resistant oxide film in space. Without protective treatment, the friction between meshing gears becomes pure metal friction, easily leading to adhesive wear and even cold welding, resulting in loss of motion and ultimately mission failure. Therefore, conducting gear life tests using a ground-based gear testing machine is of great significance for identifying space damage and improving their space performance.

[0003] Space small-module gears, commonly used for speed reduction, torque amplification, and power conversion mechanisms, are characterized by their compact structure and high power density, and are widely used in spacecraft camera focusing mechanisms, scanning mechanisms, and robotic arms. Space small-module gears are typically made of metal. Compared to the atmospheric environment, the failure modes of space small-module gears in a vacuum environment have certain unique characteristics. Because metal materials cannot form a wear-resistant oxide film in a vacuum, they are highly susceptible to adhesive wear and even cold welding, leading to loss of motion and ultimately mission failure. Therefore, conducting vacuum life tests on gears using ground-based gear testing machines is crucial for understanding the vacuum damage mechanisms of gear tooth surfaces and improving the service performance of spacecraft in the space environment.

[0004] The closest invention is a spatial gear pair transmission test bench proposed by Wang Haixia of Luoyang Institute of Technology. This test bench includes a base plate and a motor. The base plate has an upper support plate, a middle support plate, and a lower support plate. The upper support plate is mounted on the middle support plate, the middle support plate is mounted on the lower support plate, and the lower support plate is mounted on the base plate. Both the base plate and the lower support plate have T-shaped tracks, and the middle support plate has an arc-shaped track. The lower support plate can move left and right along the T-shaped track on the base plate, the middle support plate can move back and forth along the T-shaped track on the lower support plate, and the upper support plate can rotate along the arc-shaped track on the middle support plate. The motor drives the driving gear to rotate. The driving gear is supported and mounted on an adjusting base via bearing seat I. The driving gear and the driven gear form a gear pair transmission. The driven gear is supported and mounted on a base on the upper support plate by bearing seat II. This test bench can measure various spatial transmission gear pairs. The transmission form of this test bench is versatile, and it can simultaneously test gear pairs with three transmission forms: parallel shaft, intersecting shaft, and staggered shaft.

[0005] To clarify the failure patterns of gears under high vacuum conditions, it is first necessary to conduct gear performance tests on the basic unit of gear transmission, namely a pair of meshing gears. The national standard stipulates that the contact fatigue assessment of gears is based on the power closed-flow test method, with the German FZG test bench and the domestic CL-100 gear test bench being the most representative. Once the number of teeth and module of the meshing gears are determined, the center distance between the drive shaft and the driven gear shaft is also determined. In order to meet the testing requirements of gears with different numbers of teeth and modules, a variable center distance gear structure needs to be designed. However, the current variable center distance gear testing machine cannot provide torque compensation and stable load for the gear during operation. In addition, there are few reports on variable center distance gear testing machines that simulate vacuum environments. Summary of the Invention

[0006] The purpose of this invention is to provide a variable center distance gear testing machine for simulating a vacuum environment, so as to solve the problems existing in the prior art. It can change the center distance between gears during the simulated vacuum environment test, thereby increasing the test range.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] This invention provides a variable center distance gear testing machine for simulating a vacuum environment, comprising a vacuum chamber capable of creating a vacuum environment; a testing machine body disposed within the vacuum chamber, including a driving gear shaft and a driven gear shaft, the driving gear shaft and the driven gear shaft being used to connect the driving gear and the driven gear respectively, and the driving gear shaft being driven by a testing machine drive shaft, the testing machine drive shaft being externally connected to a driving device; a center distance adjustment platform disposed at the bottom of the driven gear shaft, capable of driving the driven gear shaft to move closer to or away from the driving gear shaft; and sensors disposed on the testing machine body for measuring torque, vibration, and noise signals during the testing process.

[0009] Optionally, the vacuum chamber includes a cylindrical outer shell with a sealable cover plate at its top. Inside the cylindrical outer shell, at the bottom, are positioning studs and a wiring port. The positioning studs are used to fix and install the testing machine body. The wiring port is used to pass through the data transmission line of the sensor, and after the data transmission line is passed through the wiring port, it can be sealed by an aviation connector. A drive interface is provided on the side wall of the cylindrical outer shell, and a sealing flange is provided at the drive interface. The testing machine drive shaft can be externally connected to the drive device through the drive interface.

[0010] Optionally, a support plate is fixedly provided on the outer side of the cylindrical housing near the drive interface, and the drive device is fixedly mounted on the support plate.

[0011] Optionally, the drive device is connected to one end of the test machine drive shaft via a magnetic coupling device; the test machine drive shaft is equipped with an internal stress torque generating device, which manually locks one end of the test gear set, and through levers, weights, torque sensors, and locking flanges, generates a certain constant torque at the meshing part of the gear teeth, and then locks the coupling through locking bolts to keep the meshing tooth surface of the test gears at a constant torque.

[0012] Optionally, the testing machine body further includes a testing machine base, the center distance adjustment platform is disposed on the testing machine base, the testing machine base is provided with a belt drive mechanism, one end of the testing machine drive shaft is connected to the drive gear shaft through the belt drive mechanism; the testing machine base is provided with a first rotating shaft seat, a second rotating shaft seat and a third rotating shaft seat, the testing machine drive shaft is disposed on the first rotating shaft seat, the drive gear shaft is disposed on the second rotating shaft seat and the driven gear shaft is disposed on the third rotating shaft seat.

[0013] Optionally, the belt drive mechanism includes a driving pulley located outside the first rotating shaft seat and a driven pulley located outside the second rotating shaft seat. The driving pulley and the driven pulley are connected by a closed synchronous belt. The driving pulley is connected to one end of the test machine drive shaft, and the driven pulley is connected to one end of the driving gear shaft. A tensioning pulley is provided at the bottom of the synchronous belt.

[0014] Optionally, the drive device includes a servo motor, the output shaft of which is connected to a magnetic coupling device via a coupling, and can provide forward or reverse rotation power to the test machine drive shaft during the test.

[0015] Optionally, the sensor includes a first torque sensor, a second torque sensor, a vibration sensor, and a noise sensor. The internal stress torque generating device includes the second torque sensor and a coupling. The first torque sensor is connected to the output shaft of the motor, and the second torque sensor is connected to the drive shaft of the testing machine. It can dynamically and statically test the internal stress torque value of the gear set. The flange of the vacuum chamber is a sealing element. The power transmission between the internal and external drive shafts of the chamber is realized through a magnetic coupling coupling. The torque sensor can provide real-time feedback function for the torque of the drive shaft inside the vacuum chamber, ensuring the normal operation and reliable loading of the gears inside the chamber. The motor spindle and the external drive shaft of the chamber are connected through the coupling to provide torque power input. The sensor collects, records, and stores data, and provides control basis for the control operation process. The vibration sensor and the noise sensor are respectively set at the third rotating shaft seat.

[0016] Optionally, the center distance adjustment platform includes an adjustment platform base integrally formed with the testing machine base. A third rotating shaft is connected to the guide rail of the adjustment platform base. Two parallel ball screws are provided on the adjustment platform base. The screw nuts of both ball screws are respectively fixedly connected to the bottom of the third rotating shaft. A fastening nut passes through each ball screw and is threadedly connected to it. By rotating one of the ball screws, the third rotating shaft moves. The linear motion of the third rotating shaft drives the rotation of the other ball screw, thus achieving the variable center distance function. The fastening nut is threadedly connected to the other ball screw. In the ball screw connection, after the center distance is determined, to prevent deviation during operation, the fastening nut is tightened until it abuts against the adjustment platform base, thereby limiting the movement of the ball screw and fixing the other ball screw to the adjustment platform base, preventing it from rotating and thus stabilizing the center distance. In another embodiment, the ball screw can be locked in other ways, such as by opening a limiting hole at one end of the adjustment platform base, and tightening the fastening nut on the ball screw so that one end of the fastening nut can be fixedly connected to the limiting hole, thereby limiting the movement of the ball screw. Displacement sensors can be installed on both ball screws to ensure the accuracy of the center distance adjustment.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] This invention integrates the gear testing components within a cylindrical vacuum chamber. The test objects of this testing machine are two pairs of self-lubricating planetary gear sets. The vacuum chamber achieves the sealing of the gear testing platform. An external vacuum gauge and vacuum pump are connected, and the testing environment for the self-lubricating gears is changed by adjusting the vacuum level, such as an atmospheric environment (at atmospheric pressure) and a vacuum environment (pressure less than 0.2 x 10⁻⁶). -3 Since the gears operate with dry friction, the testing machine does not require a gearbox. The transmission shaft is connected to the gears via a shrink-fit connection, which facilitates disassembly and assembly. The center distance is adjustable. The gears can collect four physical signals: torque, temperature rise, noise, and vibration. The life of the gears can be predicted by analyzing the abrupt changes in these characteristic signals. The contact fatigue life of the self-lubricating gears under two different environments, atmospheric and vacuum, is obtained by comparing the results. The life evolution law and failure mechanism of the gears are analyzed. This invention also achieves stable torque connection of the variable center distance gear testing machine through belt pulley transmission. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the variable center distance gear testing machine for simulating a vacuum environment according to the present invention;

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

[0022] Figure 3 This is a schematic diagram of the bottom of the vacuum chamber of the present invention;

[0023] Explanation of reference numerals in the attached drawings: 1-Servo motor, 2-First torque sensor, 3-Coupling, 4-Vacuum chamber, 5-Internal stress torque generating device, 6-Testing machine base, 7-Second torque sensor, 8-Testing machine drive shaft, 9-First rotating shaft seat, 10-Belt drive mechanism, 11-Driven gear shaft, 12-Second rotating shaft seat, 13-Drive gear shaft, 14-Vibration sensor, 15-Adjustment platform base, 16-Ball screw, 17-Fasting nut, 18-Third rotating shaft seat, 19-Noise sensor, 20-Connection port, 21-Positioning stud, 22-Cylindrical housing, 23-Drive interface, 24-Support plate. Detailed Implementation

[0024] 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, and 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.

[0025] The purpose of this invention is to provide a variable center distance gear testing machine for simulating a vacuum environment, so as to solve the problems existing in the prior art. It can change the center distance between gears during the simulated vacuum environment test, thereby increasing the test range.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] This invention provides a variable center distance gear testing machine for simulating a vacuum environment, see attached figure. Figure 1 Appendix Figure 2 and attached Figure 3As shown, the test machine includes a vacuum chamber 4, which can form a vacuum environment. The test machine body is set inside the vacuum chamber 4. The entire test machine body is placed in the vacuum chamber 4 and connected to a vacuum gauge and a vacuum pump. The test environment (atmosphere and vacuum) of the self-lubricating gear is changed by adjusting the vacuum level. The test machine body includes a drive gear shaft 13 and a driven gear shaft 11. The drive gear shaft 13 and the driven gear shaft 11 are used to connect the drive gear and the driven gear, respectively. The drive gear shaft 13 is driven by a test machine drive shaft 8, and the test machine drive shaft 8 is connected to a drive device. The driven gear shaft 11 is set on a center distance adjustment platform, which can drive the driven gear shaft 11 to move closer to or away from the drive gear shaft 13. Sensors are set at corresponding positions on the test machine body. The sensors include a first torque sensor 2, a second torque sensor 7, a vibration sensor 14, and a noise sensor 19, which are used to measure torque, vibration, and noise signals during the test.

[0028] Specifically, the vacuum chamber 4 includes a cylindrical outer shell 22, the top of which can be sealed with a cover plate. Inside the cylindrical outer shell 22, at the bottom, are positioning studs 21 and a wiring port 20. The positioning studs 21 are used to fix the testing machine body, and these six studs achieve positioning of the testing machine within the vacuum chamber 4. The studs are threaded, and nuts are used to securely connect the testing machine to the vacuum chamber 4, preventing vibration during operation that could affect gear operation and the accuracy of data acquisition. The wiring port 20 is used to run the data transmission line for the sensor, and also contains a data transmission cable. After transmission, the cable can be sealed via an aviation connector. A drive interface 23 is provided on the side wall of the cylindrical housing 22. The test machine drive shaft 8 can be connected to an external drive device through the drive interface 23. Specifically, the test machine drive shaft 8 is connected via a magnetic coupler, ensuring the sealing of the vacuum chamber 4 without affecting shaft operation. An internal stress torque generating device 5 is provided on the test machine drive shaft 8. The internal stress torque generating device 5 includes a torque sensor and a coupling connected to the test machine drive shaft 8. The drive device includes a servo motor 1, and the output shaft of the servo motor 1 is connected to the magnetic coupling device via a coupling 3. A support plate 24 is fixedly provided on the outer side of the cylindrical housing 22 near the drive interface 23, and the servo motor 1 is fixedly mounted on the support plate 24.

[0029] The testing machine body also includes a testing machine base 6, a center distance adjustment platform is set on the testing machine base 6, a belt drive mechanism 10 is provided on the testing machine base 6, one end of the testing machine drive shaft 8 is connected to the drive gear shaft 13 through the belt drive mechanism 10; the testing machine base 6 is provided with a first rotating shaft seat 9, a second rotating shaft seat 12 and a third rotating shaft seat 18, the testing machine drive shaft 8 is set on the first rotating shaft seat 9, the drive gear shaft 13 is set on the second rotating shaft seat 12 and the driven gear shaft 11 is set on the third rotating shaft seat 18. The center distance adjustment platform includes an adjustment platform base 15 integrally formed with the testing machine base 6. Two parallel ball screws 16 are mounted on the adjustment platform base 15. The screw nuts of both ball screws 16 are fixedly connected to the bottom of a third rotating shaft seat 18. A fastening nut 17 passes through each ball screw 16. Rotating one ball screw 16 causes the third rotating shaft seat 18 to move. The linear motion of the third rotating shaft seat 18 drives the rotation of the other ball screw 16, thus achieving the variable center distance function. The fastening nut 17 is threadedly connected to the other ball screw 16. After the center distance is determined, to prevent deviation during operation, the fastening nut 17 is tightened until it abuts against the adjustment platform base 15, thus limiting the movement of the ball screw 16 and fixing it to the adjustment platform base 15, preventing rotation and achieving a stable center distance. Displacement sensors can be installed on both ball screws 16 to ensure the accuracy of the center distance adjustment.

[0030] The belt drive mechanism 10 includes a driving pulley located outside the first rotating shaft seat 9 and a driven pulley located outside the second rotating shaft seat 12. The driving pulley and the driven pulley are connected by a closed synchronous belt. The driving pulley is connected to one end of the test machine drive shaft 8, and the driven pulley is connected to one end of the driving gear shaft 13. A tensioning pulley is provided at the bottom of the synchronous belt. The test machine body is horizontally mounted and fixed in the vacuum chamber by six positioning bolts and nuts. The input shaft is connected to the vacuum chamber 4 by a magnetic coupling device, which ensures sealing without affecting the transmission of the input shaft. Torque is applied to the driven gear shaft by hydraulic pressure or weights. The transmission and torque transfer between the driving gear shaft and the driven gear shaft are achieved by the synchronous belt connection, ensuring stable and continuously adjustable torque loading.

[0031] The first torque sensor 2 is connected to the output shaft of the servo motor 1, and the second torque sensor 7 is connected to the drive shaft 8 of the testing machine to measure the torque of the drive shaft 8. By comparing the value of the first torque sensor 2 outside the vacuum chamber, the difference between the two values ​​is observed, and appropriate torque compensation is provided to the drive shaft 8 of the testing machine. The vibration sensor 14 and the noise sensor 19 are respectively set at the third rotating shaft seat 18 to monitor the vibration and noise signals during the gear operation. Compared with the national standard gear contact fatigue test, which requires judging gear failure by pitting area, it is too cumbersome to disassemble the vacuum chamber and the gear test part multiple times. By adding sensors and using a dedicated data acquisition system to monitor the physical signals such as torque, vibration, and noise of the gear in real time during operation, and combining the pitting area ratio, a reasonable judgment of the gear failure condition is made. For example, when the gear starts to run, the values ​​of each physical signal are observed. When the pitting area reaches the failure requirement, the values ​​of each physical signal are observed again, and a relevant threshold is established for each physical signal. Subsequent tests can directly determine whether the gear has pitted failure by observing whether the signal changes reach the threshold.

[0032] In the description of this invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A variable center distance gear testing machine for simulating a vacuum environment, characterized in that: Includes a vacuum chamber, which can create a vacuum environment; The testing machine body is located in a vacuum chamber and includes a drive gear shaft and a driven gear shaft. The drive gear shaft and the driven gear shaft are used to connect the drive gear and the driven gear, respectively. The drive gear shaft is connected to the testing machine drive shaft via belt drive, and the testing machine drive shaft is externally connected to a drive device. The center distance adjustment platform is located at the bottom of the driven gear shaft and can drive the driven gear shaft to move closer to or further away from the driving gear shaft; Sensors, which are respectively installed on the testing machine body, are used to measure torque, vibration and noise signals during the test; The drive device is connected to one end of the test machine drive shaft via a magnetic coupling; the test machine drive shaft is equipped with a torque generating device; the test machine body also includes a test machine base, the center distance adjustment platform is located on the test machine base, the test machine base is equipped with a belt drive mechanism, and one end of the test machine drive shaft is connected to the drive gear shaft via the belt drive mechanism; the test machine base is equipped with a first rotating shaft seat, a second rotating shaft seat, and a third rotating shaft seat with identical structures, the first rotating shaft seat includes an angular contact bearing and a bearing seat, the test machine drive shaft is located on the first rotating shaft seat, the drive gear shaft is located on the second rotating shaft seat, and the driven gear shaft is located on the third rotating shaft seat.

2. The variable center distance gear testing machine for simulating a vacuum environment according to claim 1, characterized in that: The vacuum chamber includes a cylindrical outer shell with a sealable cover plate at the top. Inside the cylindrical outer shell, there are positioning studs and a data transmission port at the bottom. The positioning studs are used to fix the testing machine body. The data transmission port is used to run the data transmission line of the sensor, and the data transmission line can be sealed by an aviation connector after running through the data transmission port. The cylindrical outer shell has a drive interface on its side wall, and the testing machine drive shaft can be externally connected to the drive device through a magnetic coupling.

3. The variable center distance gear testing machine for simulating a vacuum environment according to claim 2, characterized in that: A support plate is fixedly provided on the outer side of the cylindrical outer shell near the drive interface, and the drive device is fixedly installed on the support plate.

4. The variable center distance gear testing machine for simulating a vacuum environment according to claim 1, characterized in that: The belt drive mechanism includes a driving pulley located on the outside of the first rotating shaft seat and a driven pulley located on the outside of the second rotating shaft seat. The driving pulley and the driven pulley are connected by a closed synchronous belt. The driving pulley is connected to one end of the test machine drive shaft, and the driven pulley is connected to one end of the driving gear shaft. A tensioning pulley is provided at the bottom of the synchronous belt.

5. The variable center distance gear testing machine for simulating a vacuum environment according to claim 1, characterized in that: The drive device includes a drive motor, and the output shaft of the drive motor is connected to a first torque sensor via a coupling.

6. The variable center distance gear testing machine for simulating a vacuum environment according to claim 5, characterized in that: The sensors include a first torque sensor, a second torque sensor, a vibration sensor, and a noise sensor. The torque generating device includes a loading clutch. The right end of the first torque sensor is connected to the output shaft of the drive motor, and the left end of the first torque sensor is connected to a magnetic coupling. The second torque sensor is connected to the drive shaft of the testing machine. The vibration sensor is located at the third rotating shaft seat, and the noise sensors are all located at the base of the testing machine.

7. The variable center distance gear testing machine for simulating a vacuum environment according to claim 1, characterized in that: The center distance adjustment platform includes an adjustment platform base integrally formed with the base of the testing machine. A third rotating shaft is connected to the adjustment platform base. The adjustment platform base is provided with two parallel ball screws. The screw nuts of the two ball screws are respectively connected to the bottom of the third rotating shaft. A fastening nut is passed through one of the ball screws. A fastening nut hole is opened at one end of the adjustment platform base. One end of the fastening nut can be threadedly fixed to the fastening nut hole.

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