Planetary gear micro-motion fatigue life test system and test method

Abstract

The present invention provides a gear mounting frame for mounting a planetary gear to be tested and an angle-adjustable excitation device; the angle-adjustable excitation device is divided into three groups, one of which acts on the shaft of the planetary gear, and the other two groups of angle-adjustable excitation devices act on the teeth of the planetary gear; the angle-adjustable excitation device includes an exciter, a support plate, a turbine, a worm and an angle adjustment motor; the support plate is divided into two groups and arranged on both sides of the exciter, the exciter is rotatably matched with the support plate through a pin shaft, the turbine is fixedly arranged on the pin shaft, the worm is meshed with the turbine, the power output end of the angle adjustment motor is matched with the worm gear transmission, and the excitation force output end of the exciter acts on the teeth and shaft of the planetary gear to be tested; an angular displacement sensor is also included, and the angular displacement sensor is used to detect the micro-motion amount of the planetary gear; it can perform a simulation test of the real working condition environment when the micro-motion fatigue test of the planetary gear to be tested is performed.

Description

Technical Field

[0001] The invention relates to the field of planetary gears, and in particular to a planetary gear micro-motion fatigue life test system and a test method thereof. Background Art

[0002] In the planetary gear transmission system, under long-term complex alternating loads, micro-motion is easy to occur at the interference fit between the outer ring of the bearing and the inner hole of the planetary gear. Micro-motion will cause micro-motion fatigue between the contact surfaces, which will greatly reduce the service life of the planetary gear system. In severe cases, it will cause cracks on the planetary gear from the inside to the outside, resulting in fatigue failure of the structure.

[0003] Fretting refers to the relative sliding of several microns to tens of microns between the surfaces of objects in contact with each other. Planetary gears and bearings are typical interference fit structures. They are subjected to rotational and bending loads during service. Therefore, serious fretting damage will occur at the edges of the interference fit parts between planetary gears and bearings.

[0004] In the prior art, the fretting fatigue test of planetary gears cannot simulate the actual working environment, resulting in low accuracy of the fretting fatigue test.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a planetary gear micro-motion fatigue life test system and a test method thereof, which can perform a simulation test of the real working condition environment when the planetary gear to be tested is subjected to micro-motion fatigue test, thereby effectively improving the accuracy of the micro-motion fatigue test of the planetary gear, and providing accurate data support for the design, subsequent operation and maintenance of the planetary gear.

[0007] The present invention provides a gear mounting frame for mounting a planetary gear to be tested and an angle-adjustable excitation device;

[0008] The angle-adjustable vibration excitation device comprises three groups, one of which acts on the shaft of the planetary gear, and the other two groups of angle-adjustable vibration excitation devices act on the teeth of the planetary gear;

[0009] The angle-adjustable vibration excitation device comprises a vibration exciter, a support plate, a turbine, a worm and an angle adjustment motor;

[0010] The support plate is divided into two groups and arranged on both sides of the exciter. The exciter is rotatably matched with the support plate through a pin shaft. The turbine is fixedly arranged on the pin shaft. The worm is meshed with the turbine. The power output end of the angle adjustment motor is matched with the worm gear transmission. The excitation force output end of the exciter acts on the teeth and shaft of the planetary gear to be tested.

[0011] It also includes an angular displacement sensor and a reaction force sensor. The angular displacement sensor is used to detect the micro-motion of the planetary gear, and the reaction force sensor is used to detect the reaction force of the planetary gear to be tested on the exciter.

[0012] Further, the vibration exciter includes a housing, an eccentric driving disk, a rocker rod, and a vibration excitation rod;

[0013] The eccentric drive disk is rotatably arranged in the housing, the swing rod is hinged in the housing, one end of the swing rod is a power input end and corresponds to the eccentric drive disk, the other end of the swing rod is in contact with and connected to the power input end of the excitation rod, and the power output end of the excitation rod extends out of the housing and acts on the planetary gear; wherein the end of the power output end of the excitation rod that acts on the shaft of the planetary gear is a curved surface structure;

[0014] The eccentric driving disk and the exciting rod are located on the same side of the rocker arm, the rocker arm is covered with a spring, the end of the power input end of the exciting rod is a step surface structure, and the spring is located between the step surface structure and the inner wall of the shell.

[0015] Furthermore, the eccentric driving disk includes a driving disk body, a connecting disk and a power input shaft, the lower surface of the connecting disk is fixedly connected to the power input shaft, the upper surface of the connecting disk is fixedly provided with a connecting portion, the connecting portion is provided with an embedding groove, the length extension direction of the embedding groove is the radial direction of the connecting disk, one end of the embedding groove is a blind end and is provided with a connecting hole, a connecting block is fixedly provided on the lower surface of the driving disk body, the connecting block is embedded in the embedding groove and fixedly connected by bolts, the bolts are threadedly matched with the connecting holes; a gasket is provided between the connecting block and the blind end of the embedding groove.

[0016] Furthermore, it also includes a lifting installation mechanism, the lifting installation structure includes a base, a lead screw and a support platform,

[0017] The base is provided with a planetary gear pair and a driving unit;

[0018] The driving unit includes a lifting turbine, a lifting worm and a lifting driving motor;

[0019] The lower end of the lead screw is coaxially fixedly connected to the planetary gear of the planetary gear pair, the upper end of the lead screw passes through the support platform and cooperates with the support platform thread, the sun gear of the planetary gear pair is coaxially fixedly connected to the lifting turbine through a connecting shaft, the lifting turbine is meshed with the lifting worm, and the power input end of the lifting worm is transmission-coordinated with the power output end of the lifting drive motor; the support plate is fixedly arranged on the upper surface of the lifting platform.

[0020] Furthermore, the angular displacement sensor is a contactless angular displacement sensor.

[0021] Accordingly, the present invention also provides a planetary gear micro-motion fatigue life test method based on the above test system, comprising the following steps:

[0022] S1. Divide the teeth of the planetary gear to be tested into M areas from meshing in to meshing out;

[0023] S2. Control the vibration exciter to apply the exciting force to the region i K times, where i = 1, 2, ..., M;

[0024] S3. Apply an exciting force to each tooth of the planetary gear to be tested according to step S2;

[0025] S4. Determine whether the micro-motion distance output by the angular displacement sensor is greater than the set maximum micro-motion distance Δ; if so, proceed to step S5; if not, return to step S1;

[0026] S5. Extract the information of the number of times the exciting force is applied, and draw the fatigue life curve of the planetary gear to be tested.

[0027] The beneficial effects of the present invention are as follows: Through the present invention, a simulation test of the real working condition environment can be carried out when the micro-motion fatigue test of the planetary gear to be tested is carried out, thereby effectively improving the accuracy of the micro-motion fatigue test of the planetary gear and providing accurate data support for the design, subsequent operation and maintenance of the planetary gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0029] Figure 1 It is a schematic diagram of the structure of the present invention.

[0030] Figure 2 It is a schematic diagram of the structure of the planetary gear pair of the present invention.

[0031] Figure 3 It is a schematic diagram of the structure of the gear mounting frame of the present invention.

[0032] Figure 4 It is a schematic diagram of the structure of the exciter of the present invention.

[0033] Figure 5 It is a structural schematic diagram of the eccentric drive disk of the present invention.

[0034] Figure 6 Schematic diagram of the meshing and disengaging of gear teeth.

[0035] Figure 7 It is a flow chart of the present invention.

[0036] Figure 8 The diagram is a schematic diagram of the structure of the exciting rod of the present invention acting on the gear shaft of the planetary gear to be tested.

[0037] Fig. 9 for Figure 1 Schematic diagram of the force on the planetary gear to be tested when the excitation force is applied by the exciter. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0039] The present invention provides a gear mounting frame 16 for mounting the planetary gear to be tested and an angle-adjustable excitation device;

[0040] The angle-adjustable excitation devices are three groups, one of which acts on the shaft of the planetary gear, and the other two groups of angle-adjustable excitation devices act on the teeth of the planetary gear; and the two groups of angle-adjustable excitation devices acting on the teeth of the planetary gear to be tested are arranged in an upper and lower manner and are located on the same side of the gear to be tested, such as Figure 1 As shown;

[0041] The angle-adjustable excitation device includes an exciter 3, a support plate 5, a turbine 4, a worm 2, and an angle adjustment motor 20. In practice, the support plate shields the entire angle adjustment motor 20 and part of the worm 2. In order to reflect the matching relationship between the worm and the turbine, Figure 1 The support plate is processed into a transparent manner;

[0042] The support plates are arranged in two groups on both sides of the exciter, which refer to the axial sides of the excitation rod. Figure 1 On both sides perpendicular to the paper direction, the exciter is rotatably matched with the support plate through a pin shaft, the turbine is fixedly arranged on the pin shaft 18, the worm is meshed with the turbine, the power output end of the angle adjustment motor is matched with the worm transmission, and the exciting force output end of the exciter acts on the teeth and shaft of the planetary gear to be tested; under the above structure, the pitch angle adjustment of the exciter can be achieved, that is, the worm is driven to rotate by the angle adjustment motor, and the worm drives the turbine to rotate, thereby achieving the pitch angle adjustment;

[0043] It also includes an angular displacement sensor 13 and a reaction force sensor 19. The angular displacement sensor is used to detect the micro-motion of the planetary gear, and the reaction force sensor is used to detect the reaction force of the planetary gear to be tested on the exciter.

[0044] The planetary gear is the transmission link between the sun gear and the ring gear in the planetary gear system. Its force analysis is the most complicated in the whole system. Fig. 9As shown. Fs-p and Fr-p represent the dynamic meshing forces between the planetary gear and the sun gear and the ring gear respectively, and Fb-p represents the supporting reaction force of the bearing on the planetary gear; therefore, through the structure proposed in the present invention, it is possible to perform a simulation test of the real working environment when the micro-motion fatigue test of the planetary gear to be tested is performed, thereby effectively improving the accuracy of the micro-motion fatigue test of the planetary gear and providing accurate data support for the design, later operation and maintenance of the planetary gear.

[0045] In this embodiment, the vibration exciter includes a housing 31, an eccentric driving disk 32, a rocker rod 33, and a vibration excitation rod 35;

[0046] The eccentric drive disk is rotatably arranged in the housing, the swing rod is hinged in the housing, one end of the swing rod is a power input end and corresponds to the eccentric drive disk, the other end of the swing rod is in contact with and connected to the power input end of the excitation rod, and the power output end of the excitation rod extends out of the housing and acts on the planetary gear; wherein the end of the power output end of the excitation rod that acts on the shaft of the planetary gear is a curved surface structure;

[0047] The eccentric driving disk and the exciting rod are located on the same side of the rocker arm, the rocker arm is outer-circuited with a spring 34, the end of the power input end of the exciting rod is a step surface structure, the spring is located between the step surface structure and the inner wall of the shell, the spring is used to reset the exciting rod to facilitate the next excitation, through the above structure, it is possible to apply stable vibration excitation to the planetary gear to be tested; wherein: the front end of the exciting rod 1 acting on the gear shaft 141 of the planetary gear 14 to be tested is a U-shaped structure, and the end thereof is an arc surface structure that conforms to the side wall of the gear shaft, so that it can act on both sides of the gear shaft at the same time to maintain the balance of the exciting force.

[0048] The eccentric drive disk includes a drive disk body 32-1, a connecting disk 32-5 and a power input shaft 32-6. The lower surface of the connecting disk is fixedly connected to the power input shaft. The upper surface of the connecting disk 32-5 is fixedly provided with a connecting portion 32-9. The connecting portion is provided with an embedding groove 32-7. The length extension direction of the embedding groove is the radial direction of the connecting disk. One end of the embedding groove is a blind end and is provided with a connecting hole 32-4. The lower surface of the drive disk body 32-1 is fixedly provided with a connecting block 32-2. The connecting block is embedded in the embedding groove and fixedly connected by a bolt 32-8. The bolt is threadedly matched with the connecting hole. A washer 32-3 is provided between the connecting block and the blind end of the embedding groove. Through the above structure, different washer thicknesses can adjust the eccentricity of the drive disk body, thereby achieving different vibration amplitudes, and the above structure is more stable and reliable. The power of the power input shaft is realized by an existing drive motor (not shown in the motor figure).

[0049] In this embodiment, a lifting installation mechanism is also included, and the lifting installation structure includes a base 10, a lead screw 7 and a support platform 6.

[0050] The base is provided with a planetary gear pair and a driving unit;

[0051] The driving unit includes a lifting turbine 8, a lifting worm 12 and a lifting driving motor 17;

[0052] The lower end of the lead screw 7 is coaxially fixedly connected with the planetary gear 9 of the planetary gear pair, the upper end of the lead screw 7 passes through the support platform 6 and cooperates with the support platform thread, the sun gear 11 of the planetary gear pair is coaxially fixedly connected with the lifting turbine 8 through the connecting shaft, the lifting turbine is meshed with the lifting worm, and the power input end of the lifting worm is matched with the power output end of the lifting drive motor; the support plate is fixedly arranged on the upper surface of the lifting platform, and through the above structure, the height of the exciter can be adjusted, the lifting worm is driven to rotate by the lifting drive motor, and the lifting worm drives the planetary gear pair to move, thereby driving the lead screw to rotate, and then the support platform moves up and down, so as to achieve height adjustment; through the joint action of the lifting platform and the pitch angle adjustable vibration device, it is possible to achieve a comprehensive test of the gear to be tested without adjusting the posture of the gear to be tested, which is convenient to use, more in line with actual working conditions, and ensures the accuracy of the test. The pitch angle and height adjustment are both adjusted by the turbine and worm, and its stability is more reliable, and the self-locking property of the worm gear is utilized, so there is no need to arrange other locking structures, simplifying the structure of the system.

[0053] Of course, a corresponding controller is also provided (one controller or three controllers can be used to control the three vibrators respectively, but a communication connection relationship needs to be established between the three controllers), which is used to receive the output signal of the angular displacement sensor and output corresponding control commands to each drive motor, and control the operation frequency of each vibrator based on the data feedback from the reaction force sensor (achieved by controlling the drive motors of each vibrator), ensure the balance of the excitation force applied by each vibrator, and record the number of excitations. The controller can adopt existing technology.

[0054] In this embodiment, the angular displacement sensor is a contactless angular displacement sensor, wherein the contactless angular displacement sensor adopts an existing structure, and the reaction force sensor is an existing force sensor, which will not be described in detail here.

[0055] Accordingly, the present invention also provides a planetary gear micro-motion fatigue life test method based on the above test system, comprising the following steps:

[0056] S1. Divide the teeth of the planetary gear to be tested into M areas from meshing in to meshing out;

[0057] S2. Control the vibration exciter to apply the exciting force to the region i K times, where i = 1, 2, ..., M;

[0058] S3. Apply an exciting force to each tooth of the planetary gear to be tested according to step S2;

[0059] S4. Determine whether the micro-motion distance output by the angular displacement sensor is greater than the set maximum micro-motion distance Δ; if greater than, it indicates that the gear to be tested has fatigue damage, and the micro-motion distance is the micro-motion amount. If so, proceed to step S5; if not, return to step S1;

[0060] S5. Extract the information of the number of times the exciting force is applied, and draw the fatigue life curve of the planetary gear to be tested; wherein, drawing the fatigue life curve of the planetary gear to be tested is a prior art and will not be elaborated here.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A planetary gear micro-fatigue life test system, characterized by: It includes a gear mounting frame for mounting the planetary gear to be tested and an angle-adjustable vibration excitation device; The angle-adjustable vibration excitation device comprises three groups, one of which acts on the shaft of the planetary gear, and the other two groups of angle-adjustable vibration excitation devices act on the teeth of the planetary gear; The angle-adjustable vibration excitation device comprises a vibration exciter, a support plate, a turbine, a worm and an angle adjustment motor; The support plate is divided into two groups and arranged on both sides of the exciter. The exciter is rotatably matched with the support plate through a pin shaft. The turbine is fixedly arranged on the pin shaft. The worm is meshed with the turbine. The power output end of the angle adjustment motor is matched with the worm gear transmission. The excitation force output end of the exciter acts on the teeth and shaft of the planetary gear to be tested. It also includes an angular displacement sensor and a reaction force sensor, wherein the angular displacement sensor is used to detect the micro-motion of the planetary gear, and the reaction force sensor is used to detect the reaction force of the planetary gear to be tested on the exciter; The vibration exciter comprises a housing, an eccentric driving disk, a rocker rod and a vibration exciter rod; The eccentric drive disk is rotatably arranged in the housing, the swing rod is hinged in the housing, one end of the swing rod is a power input end and corresponds to the eccentric drive disk, the other end of the swing rod is in contact with and connected to the power input end of the excitation rod, and the power output end of the excitation rod extends out of the housing and acts on the planetary gear; wherein the end of the power output end of the excitation rod that acts on the shaft of the planetary gear is a curved surface structure; The eccentric driving disk and the exciting rod are located on the same side of the swing rod, the swing rod is covered with a spring, the end of the power input end of the exciting rod is a step surface structure, and the spring is located between the step surface structure and the inner wall of the shell; The eccentric driving disk includes a driving disk body, a connecting disk and a power input shaft. The lower surface of the connecting disk is fixedly connected to the power input shaft. The upper surface of the connecting disk is fixedly provided with a connecting portion, and the connecting portion is provided with an embedding groove. The length extension direction of the embedding groove is the radial direction of the connecting disk. One end of the embedding groove is a blind end and is provided with a connecting hole. A connecting block is fixedly provided on the lower surface of the driving disk body. The connecting block is embedded in the embedding groove and fixedly connected by bolts. The bolts are threadedly matched with the connecting holes. A gasket is provided between the connecting block and the blind end of the embedding groove.

2. The planetary gear micro-fatigue life test system according to claim 1, characterized in that: It also includes a lifting installation mechanism, wherein the lifting installation structure includes a base, a lead screw and a support platform. The base is provided with a planetary gear pair and a driving unit; The driving unit includes a lifting turbine, a lifting worm and a lifting driving motor; The lower end of the lead screw is coaxially fixedly connected to the planetary gear of the planetary gear pair, the upper end of the lead screw passes through the support platform and cooperates with the support platform thread, the sun gear of the planetary gear pair is coaxially fixedly connected to the lifting turbine through a connecting shaft, the lifting turbine is meshed with the lifting worm, and the power input end of the lifting worm is transmission-coordinated with the power output end of the lifting drive motor; the support plate is fixedly arranged on the upper surface of the lifting platform.

3. The planetary gear micro-fatigue life test system according to claim 1, characterized in that: The angular displacement sensor is a contactless angular displacement sensor.

4. A method for testing the micro-motion fatigue life of a planetary gear based on the test system according to any one of claims 1 to 3, comprising the following steps: S1. Divide the teeth of the planetary gear to be tested into M areas from meshing in to meshing out; S2. Control the vibration exciter to apply the exciting force to the region i K times, where i = 1, 2, ..., M; S3. Apply an exciting force to each tooth of the planetary gear to be tested according to step S2; S4. Determine whether the micro-motion distance output by the angular displacement sensor is greater than the set maximum micro-motion distance Δ; if so, proceed to step S5; if not, return to step S1; S5. Extract the information of the number of times the exciting force is applied, and draw the fatigue life curve of the planetary gear to be tested.

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