| 摘要 |
<p>A speed reduction device (3, 200, 250) for a power seat adapted to be fixed to a seat frame (8), the speed reduction device includes a worm gear (72) coaxially and integrally rotating with an output shaft of a motor (62), a helical gear (82) meshed with the worm gear (72) and coaxially and integrally rotating with a drive shaft (102) driving a movable portion (42) of the power seat, and a casing (80, 201, 251) accommodating the worm gear (72) and the helical gear (82). The casing (80, 201, 251) includes a casing body (74), a casing cover (76), annular fitting portions (114, 130) formed at contact surfaces (A, B) of the casing body (74) and the casing cover (76) respectively and fitted to each other, a first engagement portion (112, 204, 254) formed at an outer circumferential side of the annular fitting portion (114, 130) of one of the casing body (74) and the casing cover (76), a second engagement portion (122, 208, 258) formed at the other of the casing body (74) and the casing cover (76) and engaging with the first engagement portion (112, 204, 254), and a tightening means (128) tightening the casing cover (76) to the casing body (74).</p> |
