SPEED CHANGE DEVICE AND VALVE TIMING AND ACTUATING DEVICE

摘要

A speed reduction device for transmitting the rotation of a drive shaft to a driven shaft in a speed reducing manner. An eccentric cam is securely mounted on the drive shaft and has a central axis eccentrically offset from a central axis of the drive shaft, and the driven shaft is rotatably mounted in eccentrically offset relation from the drive shaft by an eccentricity equal to that of the eccentric cam. The driven shaft includes a pair of opposed surface portions which are adapted to rotate in a normally clamping and circumscribing relation with respect to the eccentric cam. When the speed reduction device is used in an intake and exhaust valve timing and actuating device of an internal combustion engine, a crank shaft serves as the drive shaft, while a follower cam associated with intake and exhaust valves serves as the driven shaft.