| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress rattling of a ring gear at engine start and secure the responsiveness of the ring gear after warming-up. SOLUTION: An inner gear 31 having external teeth 38 is fitted on the tip of a camshaft 17. A cover 32 is attached on the tip of the inner gear 31. A sprocket 26 having internal teeth 41 is disposed between the inner gear 31 and the cover 32. A ring gear 33 having external teeth 45 which comprises a helical spline and internal teeth 44 is interposed between the inner gear 31 and the sprocket 26. Hydraulic chambers 48, 49 are formed at both sides of the ring gear 33 along the axis of the camshaft 17. The first sliding portion 40 of the cover 32 and the second sliding portion 43 of the sprocket 26 contact each other. The thermal expansion of the material of the first sliding portion 40 made of thermal expansive material is larger than that of the second sliding portion 43 so that the sliding resistance therbetween is established at relatively large level at engine start.</p> |
