DIFFERENTIAL GEAR, COUPLING SHAFT FOR TESTING APPARATUS OF DIFFERENTIAL GEAR, AND TEST METHOD FOR DIFFERENTIAL GEAR

摘要

A differential gear (10) that includes: a pair of side gears (30R, 30L) that are disposed concentrically to an axial line (S); pinion gears (36); and a differential case (32) configured to hold the pair of side gears (30R, 30L) such that each side gear is rotatable around the axial line (S) is included. The differential case (32) is: configured to be rotatably driven around the axial line (S) so as to differentially transmit rotation to the pair of side gears (30R, 30L) via the pinion gears (36); and provided with boss portions (44R, 44L) at portions of the differential case (32) located outside of the pair of side gears (30R, 30L) in an axial line direction. Each of the boss portions (44R, 44L) has an insertion through-hole (42R). An output shaft (18R, 18L) is inserted through the insertion through-hole (42R). At least one flat portion (60) is arranged on an outer circumferential surface of one of the boss portions (44R, 44L) so as to transmit torque. SELECTED DRAWING: FIG. 3