Abstract: An improved scroll compressor comprises a fixed scroll and an orbiting scroll, as well as an Oldham's coupling which enables the orbiting scroll to have a orbital movement. The Oldham's ring of the Oldham's coupling is so formed that its sliding surfaces for counterpart members to slide thereon are formed by a base material containing silicon particles, while the surface of each silicon particle (remaining on the base material's surface serving as a slidable surface for counterpart members to slide thereon) is formed into a flat surface. In practice, a ratio of silicon portions formed into flat surfaces to an entire sliding area of the Oldham's coupling is in a range of 3% to 20%, preferably 5% to 15%. With the use of the scroll compressor of the present invention, it is possible to improve the wear resistance of the Oldham's ring of the Oldham's coupling and its counterpart members in the scroll compressor.

Abstract: A compact, rotary gas-operated motor having only two moving components, including valving. Pressurized gas causes an elongate rotor to rotate end-over-end within a generally triangular chamber and causes a crank to slide in a slot in the elongate rotor. A disk rotating with the shaft includes ports to admit pressurized gas and exhaust spent gas. The inlet port is shaped and positioned to provide early cut-off of inlet gas and provide up to 2:1 expansion ratio of the pressurized gas. Still earlier cut-off of inlet gas, at a location between the rotating disk and its housing, provides expansion ratios as high as 9:1. A movable guillotine may be used to provide continuously variable expansion ratios of from about 3:1 to 9:1.