摘要 |
A variable valve timing system in an engine having a rotating cam-shaft includes an input pulley driven by the engine, a piston engaged with the input pulley so as to be displaceable in angular direction relative thereto, a cup-shaped casing mounted on the piston so as to be displaceable in angular direction relative thereto and connected to the cam-shaft, a cup-shaped cover accommodating therein the cup-shaped casing with a clearance and connected to the input pulley, a damper containing an amount of viscous fluid disposed in the clearance, a first sealing member disposed at one end of the clearnace, and a second sealing member disposed at the other end of the clearance, and having a characteristic in that a fluid-tight function between the cup-shaped cover and the cup-shaped casing becomes less as a centrifugal force increases.
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