Importance

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Abstract

An external combustion engine is disclosed of the type including two or more circular rotors rotatably supported, one of the rotors acting as a power rotor and rotating in tangential contact with the other sealing rotor. The power rotor is formed with a radially projecting piston passing into a mating recess with the sealing rotor at a corresponding circumferential location. Steam or other working fluid is admitted via an intake port located opposite one face of the power rotor to cause rotation of the power rotor by expansion of the fluid in a working chamber defined by the space behind the piston. As the power rotor continues to rotate, the working chamber passes into communication with an exhaust port preparator to another power stroke. A vacuum relief port is provided at an intermediate location which relieves any vacuum condition which develops behind the piston during part throttle operating conditions of the engine. A pressure balancing groove is located on a face of the power rotor and pressurized with working fluid to balance the pressure acting on the power rotor by the location of the intake port on the opposite face of the power rotor. An absorber chamber is provided downstream of the throttle valve and upstream of the intake port to smooth out the pressure forces created by intermittent flow of fluid through the intake port. An elliptical port throttle valve design is disclosed which minimizes the wire drawing effect of the working fluid acting on the valve member during operation of the valve. A special rotor sealing surface treatment is disclosed comprising a series of slight depressions or holes formed in the mating faces of the power rotor and which generate a sealing due to condensation of the escaping steam in the surface indentations. Two and three rotor versions of the engine are described as well as one, two, and four power stroke per revolution embodiments.

First Claim