| 摘要 |
PURPOSE:To prevent the side surface of a piston from being applied with a large force locally and to extend the lifetime of the relation parts by a method wherein an upper shaft and a lower shaft coupled together through a connecting rod are provided at the upper part and the lower part of the piston respectively, and the upper ends of two piston rods are pivotally attached to the lower shaft. CONSTITUTION:An upper shaft 7 is attached at a position near a piston head in a piston 4 and a lower shaft 13 is attached to the lower part of the piston 4. Both of the shafts 6 and 13 are coupled together through a connecting rod 9. Further, the upper ends of two piston rods 14 and 14' are fixed to the lower shaft 13, while the lower ends of them are coupled to cranks 19 and 19' of crank shafts 18 and 18' which are arranged at positions symmetrical with each other in a plane intersecting the center line of the piston 4 at right angles. As a consequence, the synthesized force of the forces of the piston rods 14 and 14' always makes a vector passing through the center of the piston 4 so that the side thrust of the piston 4 with respect to the cylinder 1 is avoided and the abrasion of the piston and the cylinder is reduced. |
