New Design Approach for a Scroll Compressor Anti-Rotation Mechanism

Kanetsugu Tsurutani Bearing Engineering Department NTN CORPORATION, Mie, Japan Various design concepts have been utilized for scroll anti-rotation mechanism. Each mechanism, however, has challenges which should be improved. The Ball Coupling mechanism is superior to other mechanisms when considering mechanical efficiency and balance. Based on the Ball Coupling mechanism, the "Eccentric Motion Bearing" (EM Brg) has been designed to meet various competing challenges. EM Brg unifies the Ring and Race of the Ball Coupling to single piece (unified race) and the balls are supported by the curved surface of the unified race. This unique design resulted in reduced stress between the race and the balls which made it feasible to reduce ball size diameter. EM Brg design made it possible to have a compact, light weight and simplified anti-rotation mechanism. Further NVH characteristics and productivity were enhanced.