Loads analysis and finite element simulation for cycloid ball planetary transmission

Based on the engagement principle of cycloid ball planetary transmission (CBPT), the load distribution mechanical model of engagement pair is established in condition of multi-teeth engagement, and the coefficient of load distribution of teeth is presented. The finite element model of engagement pair is established in condition of four points contact. The stress distribution of engagement pair in transmission process is simulated using the finite element method (FEM), and the effect of cycloidal curtate ratio to contact stress is analyzed. The results show that the tooth profiles which transfer force alternate with different engagement positions. The maximal stress location is at the contact place that the ball meshes with the outboard tooth profile of hypocycloid groove. The oversize cycloidal curtate ratio could bring the root amputation of cycloid groove and augment the contact stress abruptly.