Patent ID: 8829751
Filing Date: 2014-09-09
Classification: F01L,H02K

Abstract:
1. An actuator for a variable valve operating apparatus to vary a valve operating characteristic of an internal combustion engine by controlling a control shaft in the variable valve operating apparatus, the actuator comprising: an electric motor including a motor casing formed with a shaft insertion hole and a motor output shaft extending in the shaft insertion hole; a speed reducing mechanism to transmit a rotational driving force of the motor output shaft to the control shaft with speed reduction; an annular oil seal which is disposed between the shaft insertion hole and the motor output shaft and which includes an annular seal retainer buried in the annular oil seal for reinforcement; and a ring-shaped stopper member which extends circumferentially from a first end to a second end spaced from the first end, which is held in a holding portion of the shaft insertion hole and which is arranged to prevent movement of the oil seal toward the speed reducing mechanism, the stopper member including a plurality of beam segments confronting the seal retainer from an axial direction of the motor output shaft, wherein the motor casing includes the shaft insertion hole and the holding portion including a fitting groove formed in an inside circumferential surface defining the shaft insertion hole; and wherein the stopper member is a ring-shaped wire extending circumferentially from the first end to the second end spaced from the first end, and including a base segment which is held in the fitting groove, and which extends circumferentially from a first end point to a second end point, a first forward end segment which extends from a first intermediate point to the first end of the stopper member and which is held in the fitting groove, a second forward end segment which extends from a second intermediate point to the second end of the stopper member and which is held in the fitting groove, and the beam segments including first and second beam segments, the first beam segment extending from the first end point of the base segment, to the first intermediate point, the second beam segment extending from the second end point of the base segment, to the second intermediate point.