摘要 |
An object of the invention is to provide a construction for a crank device for performing power conversion between a reciprocating linear motion and a rotary motion, which construction provides a good dynamic balance and power transmission efficiency and is suitable for high-speed operation. An outer diameter of a planetary gear (21) of a planetary mechanism (4) is set to half of an inner diameter of a stationary internal gear (20), and a crank pin (12) of a crank shaft (2) is rotatably supported by and connected to the center of rotation of the planetary gear (21). A connecting rod (3) is rotatably supported by and connected to the outer peripheral portion of the planetary gear (21). Accordingly, the connecting rod (3) effects linear motion in a direction of reciprocation of a piston (15) without shaking, so that a stable dynamic balance is ensured. Further, a mass distribution for respective constituent members is set so as to provide a dynamic balance between a reciprocating section and a rotating section whereby a uniform and stable movement is ensured from a region of low-speed rotation to a region of high-speed rotation. <IMAGE> |