| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive unit of a small size, capable of blocking a reverse input from a driven part upon stopping driving force of a power source.SOLUTION: A drive unit 11 of a valve lift adjustment device comprises a motor 20 being a power source, decelerating means 27, a driving cam 501, a transmission part 40 for converting rotation motion of the driving cam 501 into linear reciprocating motion to transmit to a control shaft member 30, the control shaft member 30 connected to a controlled part so as to linearly reciprocate in the axial direction along with the transmission part 40, and a reverse-input blocking clutch 70. The reverse-input blocking clutch 70 transmits driving torque from the motor 20 side to the driving cam 501, and locks a motor shaft 23 to be not rotatable with respect to reverse input torque transmitted from a controlled part side via the driving cam 501. As a result, it is not necessary to excessively increase output of the motor 20, and thus it is possible to reduce the size of the drive unit 11. |
