| 摘要 |
In an IC engine having a crank shaft & a cam shaft, the cam shaft is rotated by the crank shaft at one-half the speed of the crank shaft and normal-closed intake & exhaust valves (2,3) are opened periodically by rocker arms(6) displaced periodically by the cams(9,10) on the cam shaft(8). Two cams fitted on a common cam shaft are offset from each other by about 180≦̸& are arranged on the rocker arms resp. The rocker arms can be operated selectively by one or both cams. Each rocker arm is maintained by the force of a spring(18) & can slide in an axial direction with respect to the cam shaft by means of hydraulic, pneumatic or electrical actuating means (13,15) against the spring force. |
