A tolerance ring is interposed between an output side rotary shaft and a rotor shaft. For this reason, even in a case where a backlash formed in a spline fitting portion between the output side rotary shaft and the rotor shaft is not eliminated, the rotary shafts of both of the output side rotary shaft and the rotor shaft are held by the tolerance ring without a backlash, and rattling noise can be suppressed. An oil supply groove for supplying a lubricant between an annular portion of the tolerance ring and the output side rotary shaft is provided inside an annular groove formed in the output side rotary shaft. With this, it is possible to suppress degradation of the durability of the tolerance ring without performing special processing on the tolerance ring.