A method for testing load sharing characteristics of a high-speed heavy-load planetary gear train

Abstract

The application provides a kind of high-speed heavy load planetary gear train load sharing characteristic test method.The method corrects the load sharing coefficient under low speed condition by dynamic load coefficient under high speed condition and dynamic load coefficient under low speed condition, and obtains the corrected load sharing coefficient under actual high speed condition.The load sharing test cost in the field of aeroengine, gas turbine and large wind power equipment can be reduced, the safety and reliability in the load sharing test process can be improved, and the survival rate of strain gauge can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-speed heavy-load planetary gear transmission, and particularly relates to a method for testing load sharing characteristics of high-speed heavy-load planetary gear train. BACKGROUND

[0002] In today's industrial field, high-speed heavy-load planetary gear transmission system has a very wide application, from the power transmission of aerospace vehicles, to the speed increasing device of large-scale wind power equipment, to the driving system of high-speed trains and other key links, which cannot do without its presence. Its reliability and stability are directly related to the performance and safety of the entire equipment.

[0003] When the planetary gear transmission system is working, uniform load sharing between each planetary gear is the key factor to ensure its efficient, stable and long-life operation. Once the load distribution is uneven, it will cause many serious problems. For example, some planetary gears bearing too high load will accelerate the tooth surface wear, shorten the gear life, and greatly increase the maintenance cost and downtime of the equipment; at the same time, uneven load may also cause the system vibration to intensify, not only producing additional noise pollution, but also causing resonance, which may damage the entire transmission system and even the connected equipment structure, threatening the operation safety.

[0004] However, the existing high-speed heavy-load planetary gear transmission load sharing test faces many challenges. The traditional test method usually requires testing under actual high-speed rated working conditions, that is, detecting the load sharing performance by loading according to the high speed and rated torque of the equipment during operation. This process requires extremely complex and expensive test equipment, because it needs to simulate high-speed operation, which has high requirements for the power source, bearings, lubrication system and control system of the test bench. On the one hand, the centrifugal force, gyroscopic moment and other dynamic effects brought by high speed make the design and manufacture of the test system difficult, and the high-precision speed control device and stable and reliable support structure are costly; on the other hand, in order to accurately measure the load distribution of each planetary gear at high speed, high-frequency response and high-precision sensors are needed, and the supporting data acquisition and processing system must also have strong real-time computing power to capture the rapidly changing load, which undoubtedly further increases the test cost.

[0005] In addition, testing under high-speed rated working conditions has a very high risk coefficient. Once an accident occurs during the test, such as sudden gear failure or poor lubrication, due to the large inertial force generated by high-speed operation, it is easy to cause serious damage to the equipment, and even endanger the safety of the on-site operators. Moreover, the preparation period for each test is long, including equipment debugging, preheating, state monitoring and other steps, which greatly reduces the test efficiency and makes it difficult to meet the efficient demand of product research and development and quality testing in the rapid development of modern industry.

[0006] To address the aforementioned issues, there is an urgent need for an innovative testing method that can overcome the drawbacks of high-speed testing while fully considering key factors under high-speed operating conditions. Summary of the Invention

[0007] The purpose of this invention is to provide a method for testing the load-sharing characteristics of high-speed, heavy-load planetary gear trains, so as to solve the problems existing in the prior art.

[0008] The technical solution adopted to achieve the purpose of this invention is as follows: a method for testing the load-sharing characteristics of a high-speed, heavy-load planetary gear train, comprising the following steps:

[0009] 1) Constructing a loading test bench. The loading test bench includes a test bench base, a power input unit, a transmission unit, a load unit, and a control and measurement unit. The power input unit, transmission unit, and load unit are mounted and fixed on the test bench base. The power input unit includes a drive motor and coupling I connected in sequence. The transmission unit includes a speed-increasing gearbox, a gear transmission device under test, and a reduction gearbox connected in sequence. The gear transmission device under test is a planetary gear system. A connecting shaft I and coupling II are provided between the speed-increasing gearbox and the gear transmission device under test. A coupling III and connecting shaft II are provided between the gear transmission device under test and the reduction gearbox. The load unit includes a load motor. A coupling IV is provided between the load motor and the reduction gearbox. The control and measurement unit includes a control cabinet and a data acquisition system. The control cabinet is used to control the operation of the drive motor and the loading of the load motor. The drive motor provides power input to the test bench and drives the gear transmission device under test. The load motor, as a loading device, provides reverse torque to the gear transmission device under test to ensure that the system operates under load. The data acquisition system includes a torque-speed sensor and strain gauges. The torque and speed sensors are suspended on couplings II and III and are used to measure the output torque and speed in real time.

[0010] 2) Attach strain gauges to the end faces of the planetary gears of the gear transmission device under test.

[0011] 3) The load-sharing test is performed using a low-speed rated torque condition instead of a high-speed rated torque condition. For high-speed, heavy-duty planetary gear transmission gearboxes, the low-speed N... low It operates under rated input torque T conditions, and during operation, strain data is collected in real time and converted into dynamic meshing force through post-processing.

[0012] 4) Calculate the load sharing coefficient B of each gear stage based on the dynamic meshing force of each gear stage. low .

[0013] 5) Calculate the dynamic load coefficient K of each gear stage under high speed and rated torque conditions. Vhigh And the dynamic load coefficient K under low speed rated torque conditions.Vlow .

[0014] 6) Introducing dynamic load coefficient to modify the uniform load coefficient. Select the uniform load coefficient B low ' which can approximately represent the uniform load coefficient B high .

[0015] Further, respectively paste strain gauges at the tangential and radial positions corresponding to the output end driven wheel. Among them, 2 strain gauges are pasted at each theoretical synchronous meshing position.

[0016] Further, holes are opened at the corresponding positions of the planetary gear and the planetary gear shaft to meet the wiring requirements of the strain gauge signal output line.

[0017] Further, in step 4), the uniform load coefficient calculation formula is as follows:

[0018] (1)

[0019] In formula (1), is the gear meshing force of each branch on the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of each branch on the left and right sides of the external and internal meshing herringbone gear, is the dynamic uniform load coefficient of the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of each gear.

[0020] Further, in step 5), the dynamic load coefficient calculation formula is as follows:

[0021] (2)

[0022] In formula (2), F t is the nominal tangential force of the meshing pair, b is the tooth width, v is the tangential velocity, z1 is the number of teeth of the driving gear, and u is the gear ratio.

[0023] Further, in step 6), the uniform load coefficient B low ' which can approximately represent the uniform load coefficient B high of the high-speed rated torque working condition can be represented by the following formula:

[0024] (3)

[0025] In formula (3), B low is the uniform load coefficient before modification of the low-speed rated torque working condition, K Vlow is the dynamic load coefficient of the low-speed rated torque working condition, K Vhigh is the dynamic load coefficient of the high-speed rated torque working condition, and B lowB is a uniform load coefficient that simultaneously corrects the uniform load coefficient of the low-speed rated torque operating condition by the dynamic load coefficient of the high-speed rated torque operating condition and the dynamic load coefficient of the low-speed rated torque operating condition. high B is a uniform load coefficient that simultaneously corrects the uniform load coefficient of the low-speed rated torque operating condition by the dynamic load coefficient of the high-speed rated torque operating condition and the dynamic load coefficient of the low-speed rated torque operating condition.

[0026] The technical effects of the present application are self-evident:

[0027] A. Without the need to build a high-precision and high-cost test bench that can withstand high-speed centrifugal force, gyroscopic moment and other complex dynamic effects, the dependence on high-end power sources, special bearings, precision lubrication systems and high-performance measurement and control systems is reduced, significantly reducing equipment procurement and manufacturing costs.

[0028] B. Avoiding many design difficulties brought by high speed, such as complex support structure, high-precision speed regulation device, etc., makes the test system structure more simple, easy to build and maintain, and shortens the test system development cycle.

[0029] C. The frequency response and accuracy requirements of the sensor at low speed are relatively relaxed, and high-frequency response, ultra-high-precision and expensive sensors are not required to meet the load distribution measurement requirements, reducing sensor procurement costs.

[0030] D. When running at low speed, even if there are sudden conditions such as gear failure and poor lubrication, the risk of equipment damage is greatly reduced due to the small inertia force, which can effectively protect the personal safety of on-site operators and reduce potential accident hazards.

[0031] E. A high-speed heavy-load planetary gear system uniform load characteristic testing method can reduce the uniform load testing cost in the fields of aircraft engines, gas turbines and large-scale wind power equipment, improve the safety and reliability during the uniform load testing process, and improve the survival rate of strain gauges. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 B is a flowchart of a high-speed heavy-load planetary gear system uniform load characteristic testing method;

[0033] Figure 2 B is a test system loading test bench structure;

[0034] Figure 3 B is a wireless strain uniform load characteristic testing signal acquisition and processing process;

[0035] Figure 4 B is the arrangement of the driven wheel measuring points and the paste position of the strain gauges;

[0036] Figure 5 B is the position of each gear pair of a certain high-speed heavy-load star gear system;

[0037] Figure 6The average value of the effective value of the meshing force of a certain type of high-speed heavy-load star gear system;

[0038] Figure 7 The average value of the amplitude of the meshing force of a certain type of high-speed heavy-load star gear system;

[0039] Figure 8 The comparison of the load sharing coefficients of a certain type of high-speed heavy-load star gear system before error correction;

[0040] Figure 9 The comparison of the load sharing coefficients of a certain type of high-speed heavy-load star gear system after error correction.

[0041] In the figure: driving motor 1, shaft coupling I 2, speed increasing gear box 3, measured gear transmission device 4, speed reducing gear box 5, connecting shaft I 6, shaft coupling II 7, shaft coupling III 8, connecting shaft II 9, load motor 10, shaft coupling IV 11. DETAILED DESCRIPTION

[0042] The application will be further described below in conjunction with examples, but should not be understood as limiting the above-mentioned subject matter of the application to the following examples. According to ordinary technical knowledge and conventional means in the art, various substitutions and modifications can be made without departing from the above-mentioned technical idea of the application, and all of them should be included in the protection scope of the application.

[0043] Example 1

[0044] This example provides a high-speed heavy-load planetary gear train load sharing characteristic test method, referring to Figure 1 , including the following steps:

[0045] 1) Set up a loading test bed. For example Figure 2As shown in the figure, the loading test bench includes a test bench base, a power input unit, a transmission unit, a load unit and a control and measurement unit. The power input unit, the transmission unit and the load unit are fixedly installed on the test bench base. The power input unit includes a driving motor 1 and a coupling I 2 connected in sequence. The transmission unit includes a speed-increasing gear box 3, a measured gear transmission device 4 and a speed-reducing gear box 5 connected in sequence. The measured gear transmission device 4 is a planetary gear train. A connecting shaft I 6 and a coupling II 7 are arranged between the speed-increasing gear box 3 and the measured gear transmission device 4. A coupling III 8 and a connecting shaft II 9 are arranged between the measured gear transmission device 4 and the speed-reducing gear box 5. The load unit includes a load motor 10. A coupling IV 11 is arranged between the load motor 10 and the speed-reducing gear box 5. The control and measurement unit includes a control cabinet and a data acquisition system. The control cabinet is used to control the operation of the driving motor 1 and the loading of the load motor 10. The driving motor 1 provides power input for the test bench and drives the measured gear transmission device 4 to operate. The load motor 10 serves as a loading device and provides a reverse torque for the measured gear transmission device 4 to ensure that the system operates in a loaded state. The data acquisition system includes a torque and speed sensor and a strain gauge. The torque and speed sensor is suspendedly installed on the coupling II 7 and the coupling III 8 and is used to measure the output torque and speed in real time.

[0046] 2) A strain gauge is pasted on the end face of the planetary gear of the measured gear transmission device 4. In this embodiment, a wireless strain gauge is used for the load sharing characteristic test, and the test signal emission-transmission-acquisition-processing process is as shown in the figure. Figure 3 During the installation of the strain gauge, the actual structure of the planetary gear needs to be considered, and the wiring requirements of the strain gauge signal output line are combined to open holes in the corresponding positions of the planetary gear and the planetary gear shaft to meet the wiring requirements.

[0047] Because the gear modulus of the high-speed heavy-load planetary gear transmission system is too small, the actual installation process does not have the condition of pasting a strain gauge between the teeth. In addition, because the input shaft of the driving gear needs to be connected with the connecting shaft, the input shaft of the driving gear cannot transmit the strain signal through the installation of an oil-electric slip ring. Based on this, in this load sharing performance test scheme, the strain gauges are pasted on the end faces of the five driven gears to achieve the purpose of testing the load sharing performance of the core machine reducer. During the load sharing performance test, the strain gauges are pasted on the tangential and radial positions of the corresponding positions of the output end driven gears, wherein 2 strain gauges are pasted at each theoretical synchronous meshing position, 2 measuring points are arranged on one side of each driven gear end face in a 180° symmetrical manner, and 1 strain gauge is arranged at the tangential position and the radial position of each measuring point. Therefore, 8 strain gauges are arranged on both sides of each driven gear; the core machine reducer has 5 driven gears, and a total of 20 measuring points, which need 40 strain gauges. The arrangement of each driven gear measuring point and the pasting position of the strain gauge are as shown in the figure.Figure 4 as shown.

[0048] 3) The low-speed rated torque condition is used to replace the high-speed rated torque condition to achieve the uniform load test content. The high-speed heavy-load planetary gear transmission gearbox is operated under the low-speed N low and rated input torque T condition, and the strain data are collected in real time during operation, and are converted into dynamic meshing force through post-processing. The positions of each pair of gears of the measured gearbox are as shown in Figure 5

[0049] A certain high-speed heavy-load star-type gear transmission system is operated under the high-speed condition Nhigh=11713 r / min, P=3 MW, and the low-speed condition Nlow=1000 r / min, T=2446 Nm. The strain data collected during operation are converted into dynamic meshing force.

[0050] The effective values and amplitude values of the dynamic meshing force of each gear under the high-speed and low-speed conditions are as shown in Figure 6 and Figure 7

[0051] 3.1) The average effective value of the dynamic meshing force of each gear under the high-speed rated torque condition is 6444.5 N for the first left gear, 6434.1 N for the first right gear, 7200.1 N for the second left gear, and 7201.7 N for the second right gear.

[0052] The average effective value of the dynamic meshing force of each gear under the low-speed rated torque condition is 6426.2 N for the first left gear, 6425.7 N for the first right gear, 7191.5 N for the second left gear, and 7191.4 N for the second right gear.

[0053] 3.2) The average amplitude value of the dynamic meshing force of each gear under the high-speed rated torque condition is 1772.3 N for the first left gear, 1610.2 N for the first right gear, 1317.4 N for the second left gear, and 1239.3 N for the second right gear.

[0054] The average amplitude value of the dynamic meshing force of each gear under the low-speed rated torque condition is 85.5 N for the first left gear, 84.5 N for the first right gear, 84.9 N for the second left gear, and 91.5 N for the second right gear.

[0055] ​​According to the analysis of the average value of the effective value and the amplitude of the meshing force, it can be known that the effective value of the dynamic meshing force of the low-speed rated torque and the high-speed rated torque of the certain type of high-speed heavy-load star gear train is basically equal, and the amplitude of the dynamic meshing force of the low-speed rated torque is much lower than that of the high-speed rated torque. It can be further known that the low-speed rated torque can be used to replace the high-speed rated torque in the uniform load test, which can ensure the effective calculation results of the two working conditions, and the low amplitude of the dynamic meshing force of the low-speed rated torque will not accelerate the wear and fatigue of the gear.

[0056] 4) The uniform load coefficients B of the gears at each stage are calculated according to the dynamic meshing force of the gears at each stage low , and the calculation formula of the uniform load coefficient is shown in formula (1).

[0057] (1)

[0058] In formula (1), is the meshing force of each branch of the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of each branch of the left and right sides of the external and internal meshing herringbone gear, is the dynamic uniform load coefficient of the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of the gears at each stage.

[0059] 4.1) The uniform load coefficients of the gears at each stage under the high-speed rated torque working condition are as follows: the first-stage left gear is 1.2333, the first-stage right gear is 1.1598, the second-stage left gear is 1.1566, and the second-stage right gear is 1.1385.

[0060] 4.2) The uniform load coefficients of the gears at each stage under the low-speed rated torque working condition are as follows: the first-stage left gear is 1.1463, the first-stage right gear is 1.0609, the second-stage left gear is 1.0598, and the second-stage right gear is 1.0628.

[0061] 4.3) It can be known that the errors of the calculated uniform load coefficients of the gears at each stage under the high-speed rated torque and the low-speed rated torque working conditions are as follows: the first-stage left gear is 7.05%, the first-stage right gear is 8.53%, the second-stage left gear is 8.39%, and the second-stage right gear is 6.65%.

[0062] 4.4) It can be seen that the calculated uniform load coefficients and the errors under the high-speed rated torque and the low-speed rated torque working conditions are shown in Table 1. Figure 8

[0063] 5) The dynamic load coefficients K Vhigh of the gears at each stage under the high-speed rated torque working condition and the dynamic load coefficients K Vlow ​, the dynamic load coefficient calculation formula (2) is as follows.

[0064] (2)

[0065] In formula (2), F t is the nominal tangential force of the meshing pair, b is the tooth width, v is the tangential velocity, z1 is the number of teeth of the driving gear, and u is the gear ratio.

[0066] 5.1) The dynamic load coefficients of the gears at high-speed rated torque are as follows: 1.09834 for the left gear of the first stage, 1.09851 for the right gear of the first stage, 1.09371 for the left gear of the second stage, and 1.09379 for the right gear of the second stage.

[0067] 5.2) The dynamic load coefficients of the gears at low-speed rated torque are as follows: 1.01837 for the left gear of the first stage, 1.0839 for the right gear of the first stage, 1.01543 for the left gear of the second stage, and 1.01548 for the right gear of the second stage.

[0068] 6) The dynamic load coefficient is introduced to correct the uniform load coefficient; the uniform load coefficient B low ′ approximately represents the uniform load coefficient B high at high-speed rated torque.

[0069] (3)

[0070] In formula (3), B low is the uniform load coefficient before correction at low-speed rated torque, K Vlow is the dynamic load coefficient at low-speed rated torque, K Vhigh is the dynamic load coefficient at high-speed rated torque, B low ′ is the uniform load coefficient that simultaneously corrects the uniform load coefficient at low-speed rated torque by the dynamic load coefficient at high-speed rated torque and the dynamic load coefficient at low-speed rated torque, and B high is the uniform load coefficient at high-speed rated torque.

[0071] 6.1) The uniform load coefficients of the gears at high-speed rated torque are as follows: 1.2333 for the left gear of the first stage, 1.1598 for the right gear of the first stage, 1.1566 for the left gear of the second stage, and 1.1385 for the right gear of the second stage.

[0072] 6.2) The uniform load coefficients of the gears at low-speed rated torque after correction are as follows: 1.2363 for the left gear of the first stage, 1.1444 for the right gear of the first stage, 1.1413 for the left gear of the second stage, and 1.1447 for the right gear of the second stage.

[0073] 6.3)It can be seen that the error of the load sharing coefficient of the high-speed rated torque and the load sharing coefficient of the actual high-speed working condition after the low-speed rated torque working condition correction is: the first left gear is 0.24%, the first right gear is 1.33%, the second left gear is 1.32%, and the second right gear is 0.54%.

[0074] 6.4)It can be seen that the error of the load sharing coefficient of the high-speed rated torque and the load sharing coefficient of the low-speed rated torque working condition after correction is as shown in Figure 9 , the maximum error is 1.33%, indicating that the load sharing coefficient calculated by the low-speed rated torque working condition after correction can represent the load sharing coefficient calculated by the high-speed rated torque working condition, and it is realized that the load sharing coefficient calculated by the low-speed rated torque working condition after correction can represent the load sharing coefficient calculated by the high-speed rated torque working condition has exceeded the ability and level of ordinary skilled personnel in the art.

[0075] The embodiment discloses a kind of high-speed heavy load planetary gear train load sharing characteristics test methods, by using a wireless strain for the load sharing characteristics test in low-speed rated torque working condition, the strain data collected by extraction tooth root strain is converted into dynamic meshing force, the load sharing coefficient is calculated by dynamic meshing force, the dynamic load coefficient in high-speed working condition and low-speed working condition is calculated respectively, dynamic load coefficient is introduced to correct load sharing coefficient, finally the load sharing coefficient after correction by dynamic load coefficient is obtained.

[0076] Example 2:

[0077] The embodiment provides a relatively basic implementation mode, a kind of high-speed heavy load planetary gear train load sharing characteristics test method, refer to Figure 1 , including the following steps:

[0078] 1) erect loading test bed. As shown in Figure 2As shown in the figure, the loading test bench includes a test bench base, a power input unit, a transmission unit, a load unit and a control and measurement unit. The power input unit, the transmission unit and the load unit are fixedly installed on the test bench base. The power input unit includes a driving motor 1 and a coupling I 2 connected in sequence. The transmission unit includes a speed-increasing gear box 3, a measured gear transmission device 4 and a speed-reducing gear box 5 connected in sequence. The measured gear transmission device 4 is a planetary gear train. A connecting shaft I 6 and a coupling II 7 are arranged between the speed-increasing gear box 3 and the measured gear transmission device 4. A coupling III 8 and a connecting shaft II 9 are arranged between the measured gear transmission device 4 and the speed-reducing gear box 5. The load unit includes a load motor 10. A coupling IV 11 is arranged between the load motor 10 and the speed-reducing gear box 5. The control and measurement unit includes a control cabinet and a data acquisition system. The control cabinet is used to control the operation of the driving motor 1 and the loading of the load motor 10. The driving motor 1 provides power input for the test bench and drives the measured gear transmission device 4 to operate. The load motor 10 serves as a loading device and provides a reverse torque for the measured gear transmission device 4 to ensure that the system operates in a loaded state. The data acquisition system includes a torque and speed sensor and a strain gauge. The torque and speed sensor is suspendedly installed on the coupling II 7 and the coupling III 8 and is used to measure the output torque and speed in real time.

[0079] 2) The strain gauges are pasted on the end face of the planetary gear of the measured gear transmission device 4. In this embodiment, a wireless strain gauge is used to test the load sharing characteristic. The test signal emission-transmission-acquisition-processing process is as shown in the figure. Figure 3 During the installation of the strain gauges, the actual structure of the planetary gear should be considered, and the holes are opened on the corresponding positions of the planetary gear and the planetary gear shaft to meet the wiring requirements of the strain gauge signal output line.

[0080] Because the gear modulus of the high-speed heavy-load planetary gear transmission system is too small, the strain gauges cannot be pasted between the teeth during the actual installation process. In addition, because the input shaft of the driving gear is connected with the connecting shaft, the strain signal cannot be transmitted through the installation of an oil-electric slip ring on the input shaft of the driving gear. Based on this, in this load sharing performance test scheme, the strain gauges are pasted on the end face of the five driven gears to achieve the purpose of testing the load sharing performance of the core machine reducer. During the load sharing performance test, the strain gauges are pasted on the tangential and radial positions of the corresponding positions of the output driven gears, wherein 2 strain gauges are pasted at each theoretical synchronous meshing position, 2 measuring points are arranged on one side of each driven gear end face at 180°, and 1 strain gauge is arranged at the tangential and radial positions of each measuring point, and 4 strain gauges are arranged at each measuring point on one side. Therefore, 8 strain gauges are arranged on each driven gear on both sides, and 40 strain gauges are arranged on the 5 driven gears of the core machine reducer, and 20 measuring points are arranged, and 40 strain gauges are needed. The arrangement of each driven gear measuring point and the pasting position of the strain gauges are as shown in the figure.Figure 4 as shown.

[0081] 3) The high-speed heavy-load planetary gear transmission gearbox operates at low speed N low and rated input torque T, and the strain data is collected in real time during operation, which is converted into dynamic meshing force through post-processing. The positions of each pair of gears in the measured gearbox are as shown. Figure 5

[0082] A certain high-speed heavy-load planetary gear transmission system operates at high speed N high =11713r / min, P=3MW, and at low speed N low =1000r / min, T=2446Nm, and the strain data collected during operation is converted into dynamic meshing force.

[0083] The effective value and amplitude of the dynamic meshing force of each gear at high speed and low speed are as shown. Figure 6 and Figure 7

[0084] 3.1) The average effective value of the dynamic meshing force of each gear at high speed rated torque condition: the first left gear is 6444.5N, the first right gear is 6434.1N, the second left gear is 7200.1N, and the second right gear is 7201.7N.

[0085] The average effective value of the dynamic meshing force of each gear at low speed rated torque condition: the first left gear is 6426.2N, the first right gear is 6425.7N, the second left gear is 7191.5N, and the second right gear is 7191.4N.

[0086] 3.2) The average amplitude of the dynamic meshing force of each gear at high speed rated torque condition: the first left gear is 1772.3N, the first right gear is 1610.2N, the second left gear is 1317.4N, and the second right gear is 1239.3N.

[0087] The average amplitude of the dynamic meshing force of each gear at low speed rated torque condition: the first left gear is 85.5N, the first right gear is 84.5N, the second left gear is 84.9N, and the second right gear is 91.5N.

[0088] ​​Analysis of the mean values ​​of the effective values ​​and amplitudes of the meshing force reveals that the effective values ​​of the dynamic meshing force of the low-speed rated torque and the high-speed rated torque of a certain type of high-speed heavy-duty planetary gear train are essentially equal. Furthermore, the amplitude of the dynamic meshing force under the low-speed rated torque is significantly lower than that under the high-speed rated torque. Therefore, using the low-speed rated torque instead of the high-speed rated torque in the load-sharing test ensures the validity of the calculation results for both operating conditions, while the lower dynamic meshing force amplitude under the low-speed rated torque does not accelerate gear wear and fatigue.

[0089] 4) Calculate the load sharing coefficient B of each gear stage based on the dynamic meshing force of each gear stage. low .

[0090] 4.1) The load sharing coefficients of each gear stage under high speed rated torque conditions are: 1.2333 for the first stage left gear, 1.1598 for the first stage right gear, 1.1566 for the second stage left gear, and 1.1385 for the second stage right gear.

[0091] 4.2) The load sharing coefficients of each gear stage under low speed rated torque conditions are: 1.1463 for the first stage left gear, 1.0609 for the first stage right gear, 1.0598 for the second stage left gear, and 1.0628 for the second stage right gear.

[0092] 4.3) It can be seen that the calculated load-sharing coefficient errors of each gear under the two working conditions of high speed rated torque and low speed rated torque are as follows: 7.05% for the first stage left gear, 8.53% for the first stage right gear, 8.39% for the second stage left gear, and 6.65% for the second stage right gear.

[0093] 4.4) It can be seen that the load sharing coefficient and error calculated for the two operating conditions, high-speed rated torque and low-speed rated torque, are as follows: Figure 8 As shown, although the errors are all within 10%, there is still a certain gap.

[0094] 5) Calculate the dynamic load coefficient K of each gear stage under high speed and rated torque conditions. Vhigh And the dynamic load coefficient K under low speed rated torque conditions. Vlow .

[0095] 5.1) The dynamic load coefficients of each gear stage under high speed rated torque conditions are: 1.09834 for the first stage left gear, 1.09851 for the first stage right gear, 1.09371 for the second stage left gear, and 1.09379 for the second stage right gear.

[0096] 5.2) The dynamic load coefficients of each gear stage under low speed rated torque conditions are: 1.01837 for the first stage left gear, 1.0839 for the first stage right gear, 1.01543 for the second stage left gear, and 1.01548 for the second stage right gear.

[0097] 6) Introducing dynamic load coefficient to modify the uniform load coefficient; selecting the uniform load coefficient B of the low-speed rated torque working condition after modification low 'Approximately representing the uniform load coefficient B of the high-speed rated torque working condition high .

[0098] 6.1) The uniform load coefficients of each stage gear under the high-speed rated torque working condition: the first stage left gear is 1.2333, the first stage right gear is 1.1598, the second stage left gear is 1.1566, and the second stage right gear is 1.1385.

[0099] 6.2) The uniform load coefficients under the actual high-speed working condition after modification of the low-speed rated torque working condition are: the first stage left gear is 1.2363, the first stage right gear is 1.1444, the second stage left gear is 1.1413, and the second stage right gear is 1.1447.

[0100] 6.3) It can be seen that the errors of the uniform load coefficients under the high-speed rated torque working condition and the actual high-speed working condition after modification of the low-speed rated torque working condition are: the first stage left gear is 0.24%, the first stage right gear is 1.33%, the second stage left gear is 1.32%, and the second stage right gear is 0.54%.

[0101] 6.4) As shown in Table 6.4, the maximum error is 1.33%, indicating that the uniform load coefficient calculated under the low-speed rated torque working condition after modification can represent the uniform load coefficient calculated under the high-speed rated torque working condition, and further recognizing that the uniform load coefficient calculated under the low-speed rated torque working condition after modification can represent the uniform load coefficient calculated under the high-speed rated torque working condition has exceeded the ability and level of ordinary technical personnel in the art. Figure 9

[0102] Example 3:

[0103] The main steps of this example are the same as those of Example 2, and further, in step 4), the uniform load coefficient calculation formula is as follows:

[0104] (1)

[0105] In formula (1), is the gear meshing force of each branch on the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of each branch on the left and right sides of the external and internal meshing herringbone gear, is the dynamic uniform load coefficient of the left and right sides of the external and internal meshing herringbone gear, is the uniform load coefficient of each stage gear.

[0106] Example 4:​

[0107] The main steps of this embodiment are the same as those of Embodiment 2, and further, in step 5), the dynamic load coefficient calculation formula is as follows:

[0108] (2)

[0109] In formula (2), F t is the nominal tangential force of the meshing pair, b is the tooth width, v is the tangential velocity, z1 is the number of teeth of the driving gear, and u is the gear ratio.

[0110] Embodiment 5:

[0111] The main steps of this embodiment are the same as those of Embodiment 2, and further, in step 6), the modified load sharing coefficient B low of the low-speed rated torque condition can be approximately expressed as the load sharing coefficient B high of the high-speed rated torque condition, which can be expressed as the following formula:

[0112] (3)

[0113] In formula (3), B low is the load sharing coefficient before modification of the low-speed rated torque condition, K Vlow is the dynamic load coefficient of the low-speed rated torque condition, K Vhigh is the dynamic load coefficient of the high-speed rated torque condition, B low is the load sharing coefficient of the high-speed rated torque condition, and B high is the load sharing coefficient of the low-speed rated torque condition, which is simultaneously modified by the dynamic load coefficient of the high-speed rated torque condition and the dynamic load coefficient of the low-speed rated torque condition.

Claims

1. A method for testing load sharing characteristics of a high speed heavy duty planetary gear train, characterized by, It comprises the following steps: 1) erect loading test bed; the loading test bed comprises test bed base, power input unit, transmission unit, load unit and control and measurement unit; the power input unit, transmission unit and load unit are fixedly installed on the test bed base; the power input unit comprises driving motor (1) and coupling I (2) connected in sequence; the transmission unit comprises speed increasing gear box (3), measured gear transmission device (4) and speed reducing gear box (5) connected in sequence; the measured gear transmission device (4) is planetary gear train; connecting shaft I (6) and coupling II (7) are arranged between the speed increasing gear box (3) and the measured gear transmission device (4); coupling III (8) and connecting shaft II (9) are arranged between the measured gear transmission device (4) and the speed reducing gear box (5); the load unit comprises load motor (10); coupling IV (11) is arranged between the load motor (10) and the speed reducing gear box (5); the control and measurement unit comprises control cabinet and data acquisition system; the control cabinet is used for controlling the operation of the driving motor (1) and the loading of the load motor (10); the driving motor (1) provides power input for the test bed and drives the measured gear transmission device (4) to operate; the data acquisition system comprises torque and speed sensor and strain gauge; the torque and speed sensor is suspendedly installed on the coupling II (7) and the coupling III (8) and is used for measuring output torque and speed in real time; 2) paste strain gauges on the driven wheel end surface of the measured gear transmission device (4); 3) Using low speed rated torque condition instead of high speed rated torque condition to achieve uniform load test content; high speed heavy load planetary gear transmission gearbox operates at low speed N low and rated input torque T condition, real-time strain data is collected during operation, and it is converted into dynamic meshing force through post-processing; 4) According to the dynamic meshing force of each gear, the load sharing coefficient B of each gear is calculated low ; 5) Calculate the dynamic load coefficient K of each gear at high speed rated torque condition Vhigh and at low speed rated torque condition Vlow ; 6) Introducing dynamic load coefficient K of high speed rated torque condition Vhigh and dynamic load coefficient K of low speed rated torque condition Vlow together correct uniform load coefficient; selecting the corrected uniform load coefficient B low of low speed rated torque condition to approximately represent the uniform load coefficient B high of high speed rated torque condition, which is expressed as the following formula: (1) In formula (1), B low is the uniform load coefficient before correction for the low-speed rated torque condition, K Vlow is the dynamic load coefficient for the low-speed rated torque condition, K Vhigh is the dynamic load coefficient for the high-speed rated torque condition, B low is the uniform load coefficient that simultaneously corrects the dynamic load coefficient for the high-speed rated torque condition and the dynamic load coefficient for the low-speed rated torque condition with respect to the uniform load coefficient for the low-speed rated torque condition, B high is the uniform load coefficient for the high-speed rated torque condition.

2. The method for testing load sharing characteristics of a high-speed heavy-duty planetary gear system according to claim 1, characterized in that: paste strain gauges on the corresponding positions of the tangential and radial directions of the output end driven wheel; wherein, 2 strain gauges are pasted at each theoretical synchronous meshing position.

3. The method of claim 1, wherein: Holes are opened on the corresponding positions of the planetary gear and planetary gear shaft to meet the wiring requirements of strain gauge signal output lines.

4. The method of claim 1, wherein, In step 4), the uniform load coefficient calculation formula is as follows: (2) In formula (2), is the gear meshing force of each branch of the left and right sides of the external and internal meshing double helical gear, is the load sharing coefficient of each branch of the left and right sides of the external and internal meshing double helical gear, is the dynamic load sharing coefficient of the left and right sides of the external and internal meshing double helical gear, is the load sharing coefficient of each stage gear.

5. The method of testing load sharing characteristics of a high speed heavy duty planetary gear set according to claim 1, wherein: In step 5), the dynamic load coefficient calculation formula is as follows: (3) In formula (3), F t is the nominal tangential force of the meshing pair, b is the tooth width, v is the tangential velocity, z1 is the number of teeth of the driving gear, and u is the gear ratio.

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