Transmission error is a key performance indicator for evaluating the transmission accuracy of planetary gear transmission systems, and it is also a source of excitation for vibration and noise in planetary gear systems. At present, research on transmission error is mostly limited to the analysis and testing of a single pair of gears, and there is little research on the transmission error and transmission process of planetary gear transmission chains. In order to support the low vibration noise and high motion accuracy design and manufacturing of transmission chains, especially planetary gear transmission chains, this article intends to deeply analyze the sources and characteristics of transmission errors, clarify the main factors that affect transmission accuracy and the key links to ensure its motion accuracy.
Based on the above analysis, the following conclusions can be drawn:
(1) The error of planetary gear transmission is mainly contributed by shaft frequency error and tooth frequency error. Generally, the amplitude of shaft frequency error is larger than that of gear frequency error, but the frequency is lower. For transmission accuracy (such as planetary cycloid precision reducers), emphasis should be placed on examining shaft frequency error; For examining vibration noise, emphasis should be placed on examining tooth frequency and its higher-order errors.
(2) The amplitude of transmission errors in fixed axis planetary gear chain transmission and planetary transmission is affected by the speed ratio during the motion transmission process, increasing/decreasing, and the frequency remains unchanged.
(3) The frequency of the transmission error of each pair of planetary gears in planetary transmission should be calculated based on their relative rotational speeds relative to the two axes (tie rods).
(4) The transmission error of a planetary cycloid reducer mainly refers to the shaft frequency error of its final stage cycloid pin wheel transmission, namely the accumulated error of tooth pitch and eccentricity error. Therefore, reducing the accumulated error of tooth pitch and eccentricity error is a key link to ensure the motion accuracy of the reducer.