| 摘要 |
PURPOSE:To reliably prevent leak of control oil, by a method wherein a housing end on the one side end side of a ring gear, on which a control oil pressure is exerted, is closed, meanwhile, a housing end on the other side end side of the ring gear is liquidtightly sealed between the housing end and a cam cover supporting a cam shaft. CONSTITUTION:A title mechanism has a ring gear 2 geared between an inner teeth 7 of a housing 1 provided on its outer periphery with a pulley 1c rotated in synchronism with an engine and an outer teeth 6 of a hollow shaft 5 engaged externally of a cam shaft 3 controlling opening and closing of a suction and an exhaust valve. At least either inner teeth 8 or outer teeth 9 of the ring gear 2 is formed in a helical tooth, the gear 2 is integrally provided at its left end with a piston 13, and is adapted to be moved rightward against a spring 14 by means of control oil introduced through oil passages 10 and 12a. In this case, the left end of the housing 1 is enclosed with a cover 16, meanwhile, a seal 20 is placed between the right end of the housing 1 and a cam cover 19, and a leak oil return passage 22 is formed between the housing and a cam shaft 3. |
