Shaft assembly using cavities for skin-friction torque reduction

摘要

PURPOSE: A shaft assembly is provided to reduce frictional torque generated when a shaft is relatively rotated with respect to a coupling member by forming a plurality of slots in the shaft or in the coupling member. CONSTITUTION: A shaft assembly includes a coupling member(10) and a shaft(20). The coupling member(10) is hollow-shaped. The shaft(20) is inserted into an inner peripheral portion(11) of the coupling member(10). The shaft(20) is rotatably inserted into the coupling member(10) and has an outer peripheral portion corresponding to the inner peripheral portion of the coupling member(10). Fluid(30) is interposed between the inner peripheral portion(11) of the coupling member(10) and the outer peripheral portion of the shaft(20). Four slots(25) are formed at the outer peripheral portion of the shaft(20).