GB580983A - Hydraulic drives - Google Patents

Abstract

580,983. Rotary engines ; speed governors. BENDIX AVIATION CORPORATION. May 8, 1944, No. 8733. Convention date, May 21, 1943. [Classes 57 and 110 (ii)] [Also in Group XXIX] The rotary vane pump 44 delivers liquid through a passage in a partition 14 to vane motor 144, the inlet to the motor having a spring-pressed valve 74, Fig. 3, which opens, preferably when a certain adjustable pressure is reached, to bye-pass liquid to the sump and so to the pump to maintain a constant pressure in the motor inlet. The motor is thus driven at substantially constant torque and may thus, e.g., operate an aeroplane cabin supercharger to maintain constant air pressure with change of altitude and engine speed. The pump and motor comprise each a series of vanes 48 having edge contact with the casing and recessed to .engage rings 52 coaxial with the casing, the engaging faces of the recess being cylindrically curved to permit rocking of the vanes. In another form, the pump delivery at a certain pressure raises a spring pressed cylindrical cup having a bye-pass hole normally blocked by a conical valve formed on the stem of a valve which at low speeds and pressures closes the motor inlet under the pressure of the cylinder spring, the valve being opened by rising pressure, its opening movement being limited by a stop. Fig. 5 shows another form in which the pump delivers through a passage 368, pressing a ball valve 372 back to pass liquid through passage 390 to the motor ; at a certain pressure, the ball and a cylinder on which it rests are forced back till the ball alone is stopped and liquid is bye-passed through the cylinder.