| 摘要 |
PROBLEM TO BE SOLVED: To provide an actuator capable of using a general ball bearing while inhibiting the occurrence of a play between the ball bearing and a housing. SOLUTION: A ball screw shaft 45 with an end 45a rotatably supported by the ball bearing 50 is rotated by the rotation drive of an electric motor 36 to move a ball nut 46 linearly in the axial direction and a control shaft is thereby rotatively controlled to variably control a valve lift amount of an intake valve. The outer ring 50a of the ball bearing is pressed from the axial direction by a spring force of a disk spring 63 via a ring member 62 and a washer 64 and is elastically held between the ring member and a stepped support face 35f of the housing 35 to absorb the play of the ball bearing to the housing by the repeated minute movement of the ball screw shaft in the axial direction during operation. COPYRIGHT: (C)2011,JPO&INPIT
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