| 摘要 |
PURPOSE:To reduce a side pressure and improve a sealing characteristic, by constituting an engine such that a cylindrical cam, forming in its upper end a cam surface and rotating with a center shaft, engages a piston in an upper end peripheral edge of the cam and rotates in a peripheral direction by pressing force of the piston. CONSTITUTION:A cylindrical cam 2, being arranged surrounding a center shaft (rotary shaft) 1, is integrally rotated with the center shaft 1. The cylindrical cam 2 is constituted by forming in two places of its upper end peripheral edge a cam surface comprising a tilt part 2b, descending at a suitable angle from an upper end part 2a, and a rise-up part 2d rising from a tilt bottom end 2c of the part 2b. And an engine, providing two pistons 3 having a groove 4 so as to hold the peripheral edge of said cylindrical cam 2 and riding it, provides in each piston 3 an upper and a bottom roller 5, 6 so as to hold the tilt part 2b from the upper and the bottom. The engine, fitting each piston 3 into a cylinder chamber 8a provided in a cylinder 8 in a fixed side, rotates the cylindrical cam 2, that is, the center shaft 1 by pressing force of said piston 3. |
