Abstract: A multistage pneumatic motor includes a shell (1) and a power output main shaft (2). The shell (1) is provided with a gas inlet (3) and a gas outlet (4). Two or more pneumatic motor stages (11, 12, 13) are installed in the shell (1). The first pneumatic motor stage is communicated with the gas inlet (3), and the last pneumatic motor stage is communicated with the gas outlet (4). Compressed gas enters the shell (1) through the gas inlet (3), drives the first pneumatic motor stage, then drives the next pneumatic motor stage, and is exhausted from the shell (1) through the gas outlet (4) at last. Every pneumatic motor stage is provided with a power output shaft (112, 122, 132) which is connected to the power output main shaft (2), so that the powers produced by all pneumatic motor stages (11, 12, 13) are jointed together and then output by the power output main shaft (2). The multistage pneumatic motor improves working efficiency greatly, saves energy source and reduces noise.

Abstract: A piston and a reciprocating expansion engine with a piston having a piston head, a piston neck, and a piston shaft are described. The piston head has at least one groove which runs in a circumferential direction suitable for receiving a piston ring, and the piston shaft has a pin boss and, at its outer circumference, a guide surface which is suitable for guiding the piston along a cylinder inner wall. An outer diameter of the piston neck is smaller than an outer diameter of the piston head and/or of the piston shaft, and the length of the piston neck approximately corresponds to the travel of the piston in the installed state.

Abstract: The present utility model is a free-piston engine comprising pinions, with various stages, providing excellent efficiency and control.

Abstract: Compressed gas is used to reciprocate pistons arranged around a nutation frame which is driven cyclically by the piston to provide a rotary output to drive a motor shaft. The cylinders have tapering walls to assist thermal flow to the gas to prevent condensation. Where the gas expansion takes place in stages, different cylinders may be dimensioned to operate under different stages of expansion of the gas.

Abstract: An external combustion engine has at least two axially spaced banks of radially disposed cylinders formed in a rotating engine block. A reciprocating piston is mounted in each cylinder. The block is rotatably mounted in an external engine housing and rotates about a first axis. A drive shaft is rotatably mounted in the external housing along a second axis parallel to but displaced from the first axis. The drive shaft extends through the central portion of the engine block and has a polygonal cross section with as many faces as there are pistons in each bank. Each piston engages a respective face of the polygonal drive shaft so that as the drive shaft and the engine block rotate together, the relative eccentric motion therebetween causes the pistons in each bank to reciprocate within their respective cylinders. A first bank of pistons is dedicated to the intake and compression of air drawn in from an air intake port in the external housing.

Abstract: A steam engine is provided including a piston having an upper end portion movable upwardly and downwardly within an internal cylindrical surface of a cylinder, toward and away from a top wall to define a first variable volume space while moving away from and toward annular means in sealing engagement with a lower reduced diameter portion of the piston to define a second variable volume space. A connecting rod has an upper end pivotally connected to the piston and a lower end pivotally connected to a crankshaft. A valve assembly is provided for flow of high pressure steam to the second space and for flow from the first space to an outlet during upward movement of the piston and for flow of steam from the second space to the first space during downward movement of the piston. Preferably, the piston has a lower end portion sealingly engaged with a second internal cylindrical surface of the cylinder to define a third space which is connected through breather passages to the exhaust outlet.

Abstract: An external combustion engine system adapted to utilize any of a number of expansible gases including steam, freon, thiophene, etc. The engine comprises a piston-driven unit which utilizes uniflow principles but is substantially more efficient than the conventional uniflow design because it provides means for conducting the exhaust from a primary side of the piston to a secondary side and thereby extracts additional energy from each gas charge through a second expansion before finally exhausting the gas to vacuum. In addition, the engine has a highly efficient and compact rotary design featuring a multi-cylinder barrel acting on a rotary torque conversion plate for minimizing friction and other energy losses. The design includes special valving for power and direction control and a simplified porting system for providing the aforementioned double gas expansion and permitting cold start-up without the need for bleed valves to drain condensate from the cylinders.