| 摘要 |
PURPOSE:To obtain a crank structure which can be prepared at low cost with little manhours of working by forming the crank shaft by connecting a main shaft constituted of a metal pipe and an eccentric shaft constituted of a metal ring. CONSTITUTION:On the outer periphery of a main shaft 8 constituted of a metal pipe body 1, an eccentric shaft 9 formed of a metal ring having the inside diameter larger than the outside diameter of the outer periphery of the main shaft 8 is installed, and a part of the inner peripheral wall is joined with the outer peripheral wall of the main shaft 8. A connecting rod 10 is constituted of a ring-shaped big end 11 which is formed by installing an inner peripheral wall in slidable manner onto the outer peripheral wall of the eccentric shaft 9 and an arm part 12 connected to a piston 6. The reciprocating movement of the piston 6 is achieved by allowing the revolution movement of the main shaft 8 to be linked with the eccentric movement of the eccentric shaft 9 installed onto the outer periphery of the main shaft 8. The distance (epsilon) between the center of the main shaft 8 and the center of the eccentric shaft 9 equals the crank radius of a crank shaft 7, and the value double the distance (epsilon) equals to the stroke of the piston 6. With such constitution, the manhours for working can be reduced remarkably. |
