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EP-4239308-B1 - SPEED REDUCER TRANSMISSION ERROR TEST APPARATUS AND METHOD

EP4239308B1EP 4239308 B1EP4239308 B1EP 4239308B1EP-4239308-B1

Inventors

  • XU, Wencai
  • SHEN, Yi
  • ZHU, Xianyu
  • TU, Bicheng
  • LI, JIANTAO

Dates

Publication Date
20260513
Application Date
20210929

Claims (8)

  1. A speed reducer (6) transmission error test apparatus, characterized in that , the test apparatus comprises: a base (1); a test workpiece (2), wherein the test workpiece (2) is provided on the output end of a speed reducer (6) to be tested, and is driven by the output end to perform synchronous rotation, and the speed reducer (6) is fixed on the base; a driving assembly, wherein the output end of the driving assembly is connected to the input end of the speed reducer (6), so that the driving assembly is used for driving the input end of the speed reducer (6) to rotate and determining the rotation angle information of the input end of the speed reducer (6); a detection assembly (4), the detection assembly (4) comprising a laser tracker (42) located at one side of the output end of the speed reducer (6), and target balls (41) provided on the test workpiece (2) and with the function of reflecting the laser light emitted by the laser tracker (42), the target balls (41) cooperate with the laser tracker (42) so as to be used for determining the motion trajectory information of the target balls (41); and a receiving assembly (5), one end of the receiving assembly (5) is electrically connected to the driving assembly, and the other end is electrically connected to the detecting assembly, and the receiving assembly (5) is used for receiving the rotation angle information of the input end of the reducer (6) and the target ball's (41) rotation angle and determining the transmission error of the reducer (6) according to the rotation angle information of the input end of the reducer (6) and the motion track information of the target balls (41), wherein the drive assembly (3) includes a motor (31), an encoder (32) electrically connected to the motor (31), and a driver controlling the motor (31), the motor (31) is located at the side of the base (1), and the extension shaft of the output end of the motor (31) is connected to the input end of the reducer (6) for driving the input end of the reducer (6) to rotate, and determining the rotation angle information of the input end of the reducer (6) through the encoder (32), one end of the driver is electrically connected to the motor (31), and the other end is electrically connected to the receiving assembly (5), the driver is used to receive the control command of the receiving assembly (5), and control the rotation of the motor (31), and send the rotation angle information of the input end of the reducer (6) determined by the encoder (32) to the receiving assembly (5).
  2. The test apparatus according to claim 1, characterized in that , the test workpiece (2) comprises a tool plate with a notch (21), an output end notch matched with the notch (21) is arranged on the output end of the reducer (6), the test workpiece (2) is matched with the output end notch through the notch (21), and rotates synchronously under the driving of the output end of the reducer (6).
  3. The test apparatus according to claim 2, characterized in that , extension arms (221) are symmetrically distributed on the tool plate, the target balls (41) are symmetrically arranged at the ends of the extension arms (221), and the number of the target balls (41) is multiple.
  4. The test apparatus according to claim 1, characterized in that , the base (1), the test workpiece (2), the reducer (6) to be tested fixed on the base (1), and the motor (31) connected to the reducer (6) are one or more, and the number of the base (1), the test workpiece (2) and the motor (31) corresponds to the number of the reducer (6) to be tested.
  5. The test apparatus according to claim 1, characterized in that , the receiving assembly (5) includes a data acquisition instrument and a display screen, the data acquisition instrument is electrically connected to the display screen, and the data acquisition instrument is configured to receive the rotation angle information of the input end of the reducer (6) and the motion trajectory information of the target balls (41), determine the transmission error of the reducer (6) based on the rotation angle information of the input end of the reducer (6) and the motion trajectory information of the target ball (41), and display the transmission error of the reducer (6) on the display screen.
  6. The test apparatus according to claim 1, characterized in that , the testing apparatus further includes a controller, the control is configured for adjusting the working parameters of the motor (31) and the laser tracker (42).
  7. A speed reducer (6) transmission error test method, configured for controlling the test device according to claim 1, wherein the method comprises: acquiring the rotation angle information of the input end of the speed reducer (6) and the motion trajectory information of the target balls (41). extracting the rotation angle of the input end of the reducer (6) according to the rotation angle information of the input end of the reducer (6), and extracting the rotation angle of the output end of the reducer (6) according to the motion trajectory information of the target balls (41); obtaining the transmission error of the reducer (6) according to the formula θer=θ2-θ1/R and the rotation angle of the input end of the reducer (6) and the rotation angle of the output end of the reducer (6), where θ1 is the rotation angle of the input end of the reducer (6), θ2 is the rotation angle of the output end of the reducer (6), θer is the transmission error of the reducer (6), and R is the reduction ratio of the reducer (6).
  8. The test method according to claim 7, characterized in that , the step of extracting the rotation angle of the output end of the reducer (6) according to the motion trajectory information of the target balls (41) includes: determining the rotation angle of the output end of the reducer (6) through the trigonometric formula θ=arctan(y/x) according to the coordinate value of the target balls (41) in the spatial rectangular coordinate system OXYZ, where x is the coordinate value of the target ball (41) in the X-axis direction in the spatial rectangular coordinate system OXYZ, and y is the coordinate value of the target ball (41) in the Y-axis direction in the spatial rectangular coordinate system OXYZ.

Description

This application claims the priority of Chinese Patent Application No. 202011172538.2 filed on Wednesday, October 28, 2020 and entitled "A Speed Reducer Transmission Error Test Apparatus and Method". TECHNICAL FIELD This application relates to the field of precision testing technology and mechanical transmission technology, and specifically to a speed reducer transmission error test apparatus and method. BACKGROUND The transmission error of the reducer is the difference between the theoretical output and the actual output of the reducer during the movement. It is a direct manifestation of the pros and cons of the internal teeth of the reducer. It essentially reflects the level of the tooth profile design and the actual processing of the reducer. The detection of the transmission error of the reducer is the detection of the input and output angles during the movement of the reducer. At present, the synchronous acquisition of the rotation angles of the input and output ends of the reducer mainly adopts the method of installing a circular grating at the input and output of the reducer. The circular grating is a high-precision sensor component with high installation requirements, and requires high assembly accuracy. When installing the circular grating at the input and output ends of the reducer, it is necessary to use a high-stability cast iron or marble platform as the basis, and also design high-precision structural parts to install and protect the circular grating, which leads to a complex and difficult test process for the transmission error of the reducer, high requirements for operators, and low test efficiency. In addition, the quasi-static test method can also be used to collect the rotation angles of the input and output ends of the reducer. The quasi-static test method is to intermittently make the input end of the reducer rotate a specified angle and then stop to test the rotation angle of the output end of the reducer. While adopting the quasi-static test method, on the one hand, because the method is to discretize the transmission error, on the other hand, the backlash and small elastic deformation are inevitably introduced at the moment of each measurement pause, which leads to a certain difference between the actual test results and the transmission error. For a high-precision product such as a reducer for a robot, this error is obviously unacceptable. At the same time, when the quasi-static test method is used to test the output end angle of the reducer, other large-scale high-precision instruments and equipment, such as three-coordinates, are also required, resulting in complicated measurement process and low test efficiency, which cannot be widely used. Therefore, the existing testing methods for the transmission error of the reducer are complicated in operation and difficult to be widely used in practical applications. CN103759939A discloses an experiment table for testing transmission errors of a high-speed-ratio high-precision speed reducer. The experiment table is composed of an input shaft rotating device, a rack and a measuring system. The measuring system is composed of an output shaft, a measuring test block and a three-dimensional measuring instrument. US2012236320A1 discloses a measurement with a system having retroreflector targets and a laser tracker includes storing a list of nominal coordinates for targets and one added point. Summary The purpose of the present application is to solve the technical problem that the operation of the test method of the transmission error of the reducer in the prior art is complicated, and it is difficult to be widely used in practical applications. In order to solve the above technical problems, the present application provides a test apparatus, including: a base; a test workpiece, wherein the test workpiece is provided on the output end of a speed reducer to be tested, and is driven by the output end to perform synchronous rotation, and the speed reducer is fixed on the base; a driving assembly, wherein the output end of the driving assembly is connected to the input end of the speed reducer, so that the driving assembly is used for driving the input end of the speed reducer to rotate and determining the rotation angle information of the input end of the speed reducer; A detection assembly, the detection assembly comprising a laser tracker located at one side of the output end of the speed reducer, and target balls provided on the test workpiece and with the function of reflecting the laser light emitted by the laser tracker, the target balls cooperate with the laser tracker so as to be used for determining the motion trajectory information of the target balls; and a receiving assembly, one end of the receiving assembly is electrically connected to the driving assembly, and the other end is electrically connected to the detecting assembly, and the receiving assembly is used for receiving the rotation angle information of the input end of the redu