GB858748A - Free piston hydraulic system - Google Patents

Abstract

858,748. Hydraulic turbines. PEREDA, C. V. Oct. 27, 1959, No. 36448/59. Class 110 (3). [Also in Groups XXVIII and XXIX] An hydraulic power transmission system comprises a prime mover 1, 2 having at least two cylinder-mounted pistons 11, 12 reciprocably movable in opposite directions with respect to each other, the cylinders 9, 10 being connected to respective ports of a distributer 18 having an outlet port connected to the inlet of a constant speed and volume motor unit 21 having its,outlet connected to one or more fluid-driven power take-offs 29, 33, in turn connected to a return port of the distributer. The constant speed and volume motor 21 has a shaft 24 on one end carrying a flywheel 25 and at the other end connected to the rotor of a variable volume bypass controller 26, the eccentricity of the rotor being variable by a lever 37 or a pressureresponsive device 38 in the line to a power takeoff 33 to vary the, flow through, and hence speed of, the power take-off 33. All the fluid passing through the power take-off 33 and the by-pass controller 26 passes through the power take-off 29 which is thus supplied with a constant volume of fluid and rotates at a constant speed. Both power take-offs may be of the rotary turbine type. The distributer has a disc 49 in which are parallel bores 54, 55 and crossed bores 56, 57, the disc being rotated at the end of each stroke of the pump pistons by a cam-and-follower device 52 on the shaft 24. The pistons 11, 12 are reciprocated by the prime movers 1, 2 which may be driven by internal combustion. During downward movement of the pump piston 11, fluid beneath the piston passes through a pipe 13 to the lower end of cylinder 10 to move the piston 12 upwardly, fluid above that piston passing through a pipe 17 and one of the parallel bores into a pipe 19 leading to the motor 21. At the end of the stroke of the piston, the disc 49 of the distributer is rotated so that, during the upward movement of the piston 11, fluid above that piston can pass through a line 16 and one of the crossed bores 55 to the line 19 and motor 21, so that the motor 21 and power take-offs always rotate in the same direction. In other embodiments, two constant-speed take-offs may be arranged in series or in parallel and the pistons of the engines 2, 3 be arranged to reciprocate in the same cylinder, the rods of the pistons being connected by links to the pump pistons which are arranged parallel to the engine pistons.