GB524384A - Improvements in radial pumps - Google Patents

Abstract

524,384. Revolving-cylinder pumps. AIRCRAFT HYDRAULIC APPLIANCES, Ltd., WYLIE, H. N., and GROVES, W. R. Dec. 21, 1938, Nos. 37140/38 and 19877/39. [Class 102 (i)] [Also in Group XXXIV] In a pump of the kind comprising radial cylinders rotating in an eccentric track-ring, the cylinder-assembly is arranged to act as an impeller for centrifuging the working fluid from an inlet to an outlet disposed relatively near to and remote from the axis, the outlet having branches communicating with the cylinderassembly and an external cooling-circuit. The construction ensures adequate cooling of the pump and, when the pump is employed for lubricants, also ensures lubrication of the working parts. The pump shown in Figs. 1 and 2 is similar to that described in Specification 524,199 and comprises a block of cylinders 5 revoluble on a stationary spindle 7 and driven by a shaft 8. Pistons 6 in the cylinders have slippers 11, described below, engaging a trackring 3 which can rock on a knife-edge 2B on the casing 1 and is urged by a spring 4 into the position of maximum eccentricity in relation to the spindle. The part 1B to 1C of the casing is concentric to the knife-edge and acts as a guide for the track-ring. Ducts 7B, 7A in the spindle open into grooves 7C, 7D which are separated by lands 7E, 7F and communicate with ports 5B in the cylinders when the cylinder-block rotates. The casing 1 and duct 7B are provided with an inlet 1A and an outlet 10, and the casing is formed with a divergent passage 1D communicating through a duct 1E with the groove 7C. The duct 1E communicates also through a branch 1F and a valve or constriction with the liquid-source. The cylinder-block acts as a centrifugal impeller and forms a first-stage low-pressure pump, part of the output being fed to the cylinders, these constituting with the pistons a high-pressure pump. When the pump is idling, the centrifugal liquid maintains a cooling flow through the pump. The cylinders may be provided with vanes or webs. The trackring swings under control of the output pressure to vary the eccentricity of the track-ring and consequently the stroke of the pistons. Each slipper 11, Figs. 1 and 2, has pads engaging the channelled track-rings 3, and a bridge 12 which can rock with line-contact on a convex surface 6A at the bottom of a slot in the head of the piston 6, the rocking movement being resisted by a retaining wire 11B which passes through lugs 11A on the slipper, and a hole in the piston. The pads act as Michell bearings, the parts ahead of the web 12 in the running direction being somewhat longer than the parts at the rear. In an alternative pump-construction, Fig. 5 (not shown), the track-ring is formed with a divergent channel through which the centrifugal liquid flows to the inlet-duct of the cylinders. The track-ring rocks on a pin mounted in the casing and formed with an outlet-passage.