Radial piston machine

A radial piston machine comprising a housing having a control trunnion integrally formed therewith and an annular portion surrounding said control trunnion radially spaced therefrom to form an annular chamber open at one side;

• a cover closing the open side of said chamber;
• a rotor rotatably mounted on said control trunnion and having a plurality of radial bores having open inner and outer ends;
• a plurality of pistons respectively slidable in said bores and having outer ends projecting through said open outer ends of said bores beyond the outer periphery of said rotor;
• a displacement ring in said chamber eccentrically arranged with respect to said rotor and having an inner surface engaged by the outer ends of said pistons to move the latter during rotation of said rotor between suction and compression strokes, said inner surface of said displacement ring being radially spaced from the outer surface of said rotor and forming therewith a radial gap of varying height;
• an inlet channel in said housing on the side of said rotor opposite of said cover;
• passage means in said housing providing communication between said inlet channel and said gap;
• a suctions slot in said trunnion communicating during rotation of said rotor with the inner ends of those bores in which the pistons move radially outwardly along the suction stroke;
• a cross-slot in said trunnion opposite said suction slot and communicating during rotation of said rotor with the inner ends of those bores in which the pistons move radially inwardly along the compression stroke;
• an outlet channel in said housing;
• at least one bore through said trunnion substantially parallel to the axis thereof and providing communication between said cross-slot and said outlet channel;
• an axial bore in said trunnion and a shaft extending through said axial bore and with one end thereof beyond the housing at the side of the latter opposite said cover;
• coupling means at the other end of said shaft for coupling the shaft to the rotor, said coupling means comprising a coupling disc, and said rotor and said coupling disc being provided with interengaging radial slots and ridges, said coupling disc having axial passages permitting flow of fluid therethrough into said suction slot;
• and channel means in said cover and providing communication between said gap and said suction slot, said channel means comprising an outer annular channel in the region of said gap, an inner annular channel in the region of said axial passages in said coupling disc, and a plurality of connecting channels displaced circumferentially from each other and providing communication between said outer and said inner annular channel.