ACTUATOR FOR LINK MECHANISMS FOR INTERNAL COMBUSTION ENGINES

Provided is an actuator for link mechanisms for internal combustion engines, the actuator being configured so as not to have an increased axial length. An actuator for link mechanisms for internal combustion engines is provided with: a harmonic drive type speed reducer for reducing the speed of an electric motor and transmitting the reduced speed to a control shaft; and a housing to which the electric motor and the harmonic drive type speed reducer are affixed. The harmonic drive type speed reducer has an internally toothed gear. The internally toothed gear is affixed to the housing, has internal teeth meshing with flexible external teeth, and is formed from an iron-based metallic material. The actuator has stopper mechanisms which are respectively integrally mounted to the internally toothed gear and the control shaft and which come in contact with each other to prevent relative rotation beyond a predetermined amount. 提供种能够抑制向轴向增大的内燃机用连杆机构的促动器。在本发明的内燃机用连杆机构的促动器中，具有：波动齿轮型减速器，所述波动齿轮型减速器对电动马达的转速进行减速并传递到所述控制轴；以及