Comparison of Two Cycloidal Wheel Modification Methods

Abstract

RV reducer is a commonly used transmission device in the industrial robot system. It incorporates two stage drive; the first stage uses involute planetary gear and the second stage uses cycloidal pin wheel. In order to make up for thermal expansion and manufacturing errors and ensure that the meshing portion of the cycloidal wheel is close to the conjugate tooth profile, the cycloidal wheel needs to be modified. The calculation results show that when the combination modification including positive equidistance modification and negative moved distance modification method is adopted, the modified cycloidal tooth profile more closely approaches the original tooth profile. In the method of cycloidal wheel modification, the tooth profile after modified by rotated angle is generally used as the objective function for fitting. The traditional fitting range is a complete tooth profile, while the fitting range in this paper is only limited to the meshing area. Finally, we get the equidistance modification amounts and moved distance modification amounts after modified by two methods. We compared the two methods: the results show that both the tooth profile designed by the new method and the traditional method can mesh effectively in the meshing area. But in the tooth top, the tooth profile designed by the new method has a larger gap, which can better meet the modification requirements.