| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the size of an internal gear 4, and to enhance mechanical strength. <P>SOLUTION: A sun gear 6 is concentrically fitted inside the internal gear 4 to be rotatable. A plurality of planet gears 8 held by a planetary carrier 10 are arranged between the internal gear 4 and the sun gear 6, and are meshed with the internal gear 4 and the sun gear 6. The planetary carrier 10 holding the planet gears 8 is connected to a shaft at an engine side, and the internal gear 4 and the sun gear 6 are respectively connected to a shaft at an output side. The internal gear 4 is subjected to a heat treatment such as nitrocarburizing, nitriding, and carburizing and quenching after being formed by a plastic forming. An internal tooth 4b is formed inside the internal gear 4 while leaving a part 4d in an axial direction. A spline groove 4a is provided to an outside surface side of the part 4d in which the internal tooth 4b is not formed, and is engaged with a spline groove 2a of a housing 2. <P>COPYRIGHT: (C)2004,JPO</p> |
