Actuator of link mechanism for internal combustion engine and actuator for variable compression ratio mechanism

摘要

An actuator of a variable compression ratio mechanism which includes: a control link; a control shaft; a housing; a wave gear speed reduction device arranged to transmit the reduced rotation speed to the control shaft; a first bearing portion which is provided between the control shaft and a wave generation device of the wave gear speed reduction device, and which rotatably supports a first axial end portion of the wave generation device; and a second bearing portion which is provided between the housing and the wave generation device, and which rotatably supports an second axial end portion of the wave generation device, at least one of the first bearing portion and the second bearing portion being disposed inside an axial width of an outer circumference portion of the wave generation device.

主权项

1. An actuator of a variable compression ratio mechanism which is arranged to vary at least one of a top dead center position and a bottom dead center position of a piston of an internal combustion engine, and thereby to vary a mechanical compression ratio, the actuator comprising:
a control link including a first end portion connected to the variable compression ratio mechanism, and a second end portion, and arranged to vary a position characteristic of the piston; a control shaft which is connected in an eccentric state through an arm link to a second end portion of the control link; a housing which includes a support hole formed within the housing, and which rotatably supports the control shaft; a wave gear speed reduction device which is arranged to reduce a rotation speed of a drive motor, and to transmit the reduced rotation speed to the control shaft; a first bearing portion which is provided between the control shaft and a wave generation device of the wave gear speed reduction device, and which rotatably supports a first axial end portion of the wave generation device; and a second bearing portion which is provided between the housing and the wave generation device, and which rotatably supports a second axial end portion of the wave generation device, at least one of the first bearing portion and the second bearing portion being disposed inside an axial width of an outer circumference portion of the wave generation device.