GB696649A - Improvements in or relating to variable capacity rotary hydraulic pumps and motors - Google Patents

Abstract

696,649.. Rotary engines or pumps. KEELAVITE CO., Ltd. Nov. 1, 1951 [Nov. 6, 1950], No. 27078/50. Class 110(ii) An engine (or pump) of the rotary-abutment type, such as described in Specification 551,991, in which the capacity of the working-chamber is varied by an axial movement of an end-wall C', is provided with automatic valve apparatus which controls the flow of fluid through passages 5<SP>3</SP> 5<SP>4</SP>, leading to the working chamber B and recesses F <SP>2</SP> respectively. Outflow of fluid from B and F<SP>2</SP> occurs when the pressures therein exceeds the inlet pressure to the engine, and inflow fluid when the pressures therein are less than the fluid pressure at the exhaust port. Either port L or M may be the inlet, the valve apparatus automatically allowing for the reversing of the pressures and reversal of the rotor shaft H carrying vanes H<SP>4</SP>. The recesses F<SP>2</SP>, and opposite flats F<SP>7</SP>, of the abutment, are connected by passages F<SP>4</SP>, F<SP>5</SP> respectively. The motor, preferably, is contained within a casing A which is filled with fluid under a pressure intermediate the pressures in the ports L, M. Gears F<SP>3</SP>, H<SP>3</SP> couple the two shafts F, H together. A link N is used to move the shaft H, and its rotor H<SP>1</SP>, axially. In Fig. 2, a valve R will close a passage R<SP>1</SP> or R<SP>2</SP> depending upon which port M or L is at high pressure. This pressure, through a pipe Q, acts on the end P<SP>1</SP> of a differential piston P. While the pipe Q is always at high pressure, a pipe P<SP>7</SP> is always subjected to the lower pressure. The larger end P<SP>2</SP>, of the valve P, is subjected to the pressure of fluid in the casing A, and a port P<SP>4</SP> is. also open to A. When the pressure in the casing A drops below the mean of the pressures in P<SP>3</SP> and P<SP>5</SP>, the valve P will be moved to the right so as to open the port P<SP>4</SP> and admit additional working, fluid from the end P<SP>3</SP> to the casing. When the wall C<SP>1</SP> is moved to the left to decrease the capacity of the motor, fluid will be able to escape from the chamber B when it is shut off between the two vanes H<SP>4</SP>, Fig. 2, by way of the passage 5<SP>3</SP> and a valve 5. If the wall C<SP>1</SP> moves to the right, to increase the capacity of the motor, fluid can be drawn into the port 5<SP>3</SP> from the pipe P<SP>7</SP> through a valve 5<SP>1</SP>. In an alternative arrangement, Fig. 7 (not shown) the valves 5, 5<SP>1</SP> are duplicated for the passage 5<SP>4</SP>. The Provisional Specification also refers to Specifications 524,503 and 551,482.