| 摘要 |
A device for angularly displacing a camshaft (13) relative to the crankshaft of an internal combustion engine to vary engine valve timing. The device comprises a hub (17) fixed to the camshaft (13), an annular means (23) threadedly engaged with the hub (17) or with an advancing member (24) mounted on the outer surface of the annular means. Angled lugs (32) formed on a drive member coact with angled slots (35) formed on the outer periphery of the advancing member. The amount of angular displacement of the drive member (15) relative to the hub (17) and camshaft (13) is directly proportional to the axial displacement of the advancing member (24) which in turn is moved axially as the annular means (23) is moved axially along the threads (21, 22) on the hub or on the advancing member. The latter movement is effected by applying a retarding or braking torque to the annular means via the retarder means (36). |
