VARIABLE COMPRESSION RATIO MECHANISM ACTUATOR AND LINK MECHANISM ACTUATOR

摘要

PROBLEM TO BE SOLVED: To provide a variable compression ratio mechanism actuator capable of suppressing increasing in the size and weight of a housing.SOLUTION: A variable compression ratio mechanism actuator comprises: a second control link 12 changing positional characteristics of a piston; an arm link 13 rotatably coupled to the other end 12b of the second control link 12; a second control shaft 11 provided separately from the arm link 13 and fixed to the arm link 13; a housing 20 that includes a storage chamber 29 in which coupled regions between the other end 12b of the second control link 12 and a protrusion 13b of the arm link 13 are accommodated and disposed; and a decelerator 21 reducing a rotational speed of a drive motor 22 and transmitting the reduced rotational speed to the second control shaft 11, a shaft body 23 including a fixed portion 23c inserted into and fixed to a fixing hole 13a formed generally at an axial center in the arm link 13, and a first journal 23a formed in a tip end portion to have a smaller diameter than that of the fixed portion 23c, and pivotally supported by a first bearing hole 30a formed in the support hole 30.