Geometry design and dynamic analysis of a modified cycloid reducer with epitrochoid tooth profile

Abstract

This study proposes a design method for a modified cycloid reducer with an epitrochoid tooth profile. The reducer used here has one contact pattern and non-pin rollers like a planocentric reducer. This feature makes the designed reducer easier to be manufactured compared to conventional cycloid reducers, which are difficult to manufacture due to tolerances. The tooth profile characteristics for nine different design scenarios for the cycloid reducer were analyzed with respect to the tooth thickness ratio and the distance from the center of the rolling circle. It was observed that the inflection point, which was calculated from the radius of curvature, was a major factor influencing the design of the cycloidal tooth profiles. A mathematical model for the force analysis of the designed reducer was developed, and variations in force distribution between the internal and external gears as well as the efficiency of the cycloid reducer were calculated according to different coefficients of friction. Involute and cycloid gears with a difference of one tooth between the internal and external gears were designed and manufactured, and finite element analysis showed that the cycloid gear had higher rigidity than the involute gear.