| 摘要 |
<p>A drive force transmission apparatus (17) disposed within a differential carrier (22) and adapted to drivingly couple first and second rotary shafts (15,18). The drive force transmission apparatus includes an outer casing (31) coupled to the first rotary shaft (15), an inner shaft (32) coupled to the second rotary shaft (18), a frictional clutch (33) which enters a frictionally engaged state upon reception of a thrust force to thereby couple the outer casing and the inner shaft together, and an electromagnetic drive mechanism (35) for generating the thrust force. The electromagnetic drive mechanism includes an electromagnet (63) disposed outside the outer casing, a yoke (43) supporting the electromagnet, the yoke being fixedly supported by the carrier in such a manner that the yoke faces a side wall of the outer casing with a gap (1) formed therebetween, and a thrust force generation mechanism (36) disposed inside the outer casing and adapted to produce the thrust force to be applied to the frictional clutch upon receipt of a magnetic force from the electromagnet via the gap and the side wall of the outer casing. A surface of the yoke and a surface of the side wall of the outer casing which face the gap each have a hardened surface layer. <IMAGE></p> |
