| 摘要 |
PURPOSE:To reduce the reciprocating mass, to decrease the noise in the sliding, and to improve the assembly work efficiency, by holding spheres with a circular groove provided to a shaft, and a circular groove provided to a keep plate made of a reinforced synthetic resin which is fixed to the upper side of the shaft. CONSTITUTION:In a crankshaft 14, a shaft 13 furnishing an oil hole 11 in the axial direction and a circular groove 12 on which spheres 9 slide, and a keep plate 17 made of a reinforced synthetic resin furnishing a circular groove 16 fixed to the upper side of the shaft 13 and spheres 9 slide on are provided. While spheres 9 are held between the circular grooves 12 and 16, the center axis L of both circular grooves is formed deflecting from the axial center M of the shaft 13. As a result, by making the shaft 13 and the like also of the reinforced synthetic resin, the major parts of the crank 10 can be formed of the reinforced synthetic resin, and the reciprocating mass can be reduced. And since a shaking between the spheres 9 can be suppressed by the elasticity of the keep plate 17 itself, a noise in the sliding can be reduced. Furthermore, since the number of parts can be reduced, the assembly work efficiency can be improved. |
