Actuator of internal combustion engine link mechanism and actuator of 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.