GB580859A - Improvements in or relating to rotary cylinder pumps - Google Patents

Abstract

580,859. Rotary cylinder pumps. DEXTER, G. March 7, 1944, Nos. 4267 and 22567. [Class 102 (i)] A rotary cylinder pump capable of delivering oil at variable pressure and flow comprises a "wobbler" cylinder 'block 1, Fig. 1, mounted at variable inclination by an interior universal joint 6 mounted on a driving shaft 7 and two banks of cylinders in which reciprocate pistons 3 in opposite faces of the block and actuated by cone-faced collars 8, 9 or other rigid means fixed to the shaft 7. The pressures within the two banks of cylinders are balanced so as not to disturb the inclination of the "wobbler" cylinder block, as also are the piston reactions on the driving shaft through the rigid actuating means. Inlet and outlet cylinder ports 4 communicate in order with slots and passages in the cylinder block housing 11, which slots in turn communicate with the main inlet and outlet ports. Rotor tilt, and hence stroke variation and delivery pressure are automatically controlled by a plunger 18 on a hollow spindle through which the plunger, at the space 21, is subjected to delivery pressure acting against the pressure of a metering- spring 51, Fig. 3, which comprises a straight edged lever 35 with an edge 36 bearing on one of fulcra 38, 39, 40 and acts through a rocking lever 28 and push-rod 31 to rotate the shaft 29 to which lever 28 is fixed. A knuckle-joint connects the device to a servo-piston 54 loaded by the spring 51 which is itself adjusted by a temperature sensitive capsule 44 in connection with a gas-filled tube in the engine manifold. Expansion of the capsule rotates the lever 28 through a spindle 45, spring 51 and levers 35, 33 in an anti-clockwise direction, thereby increasing rotor tilt and hence piston stroke and delivery pressure. Pressure in the space 21 is controlled so as to balance the opposing load applied by the servo-piston and metering- spring by a valve 62, Fig. 5, which when opened by the forward movement of a spider (not shown) mounted on a collar 49, Fig. 3, abutting a ring 59 allows oil under pressure to enter the pump casing. Closing the valve by backward movement of the spider allows oil to flow from the pump casing to an oil-drum duct 23. In a modification, the rotary cylinder block 75, Fig. 6, is housed in a trunnion member 82 mounted on bearings at opposite sides of the pump casing 78. The internal surface of the trunnion member is provided with two pairs of arcuate slots 89 one of each pair being cross-connected and open to the casing interior, and the other slots connected through closed spaces to a delivery. passage. On the suction stroke, ports 87 of bores 88 communicate with the cross-connected open arcuate slots 89, and on the delivery stroke the ports 87 communicate with the closed arcuate slots and the delivery passage. Rotor tilt is automatically controlled by a piston 101 urged by the delivery oil to act against, a spring-urged piston 98. The maximum value of the oil delivery pressure may be stepped up by the use of a magnetically operated valve 103 as described in Specification 569,658. In a further modification, the rotary cylinder block is formed in two spring-pressed terminals mounted on either side of a non-rotary block, the three blocks being mounted on a sleeve driven by a universal joint mounted on the main shaft. Rotor tilt is controlled by the delivery-pressure acting on a plunger opposed by a spring member. In a still further modification, the rotor is in two halves, with opposing banks of cylinders in the inner faces, and seated on a ball joint integral with the main shaft. Rotor tilt is controlled by delivery-pressure acting on a plunger opposed by a spring member.