| 摘要 |
<p>PURPOSE:To enable valve timing control with high accuracy and smoothness by relatively rotating a cam shaft and a rotational body while transmitting a torque of the rotational body to rotational members, and performing relative rotational conversion through a rotational conversion mechanism. CONSTITUTION:A driven sprocket 3 is rotatably supported to one end 1a of a cam shaft 1, on whose end 1a a gear 4 is installed. The driven sprocket 3 has a sprocket main body 6 which has a double tooth profile 6a on its outer periphery and substantially U-shape in its section. A pair of worms 14, 15 respectively meshing with both sides of a gear 4 are rotatably formed between bearings 12a and 12b, 13a and 13b. The respective worms 14, 15 are rotated by the rotation of disc-like rotational members 26, 27 which have comparatively large diameters through the meshing with first spur gears 18, 19 and second spur gears 24, 25. The rotational members 26, 27 axially move a pair of bilateral unrotational members 29, 30 arranged on both sides of the driven sprocket 3. One of the unrotational members 29, 30 is brought in contact with the rotational members 26, 27, and thereby normal or reverse rotation may be realized.</p> |
