Patent ID: 7997853

Claim:
In a pressure transfer device for transferring pressure energy from a high pressure first fluid to a lower pressure second fluid to provide a pressurized second fluid, which device includes: a cylindrical rotor mounted to revolve about its axis and having a pair of opposite planar end faces with at least two channels extending axially therethrough between apertures located in said planar end faces; and a pair of opposite end covers having axially inward and outward end surfaces, with said inward end surfaces interfacing with and slidingly and sealingly engaging said respective opposite end faces of said rotor, each said end cover having one or more inlet passageways and one or more discharge passageways which open into said axially inward surfaces, said opposite end covers being aligned so that when one rotor channel is aligned with an inlet passageway opening in one said end cover, it is also aligned with a discharge passageway opening in said other end cover, said inlet passageway and discharge passageway openings in the same end cover being constantly sealed from each other during operation by a sealing region at the interface between said rotor end face and said end cover inward surface, whereby, as a result of revolution of said rotor, each said rotor channel is, in alternating sequence, brought into partial or full alignment with a high pressure inlet passageway opening in one said end cover and a high pressure discharge passageway opening in the other said end cover and then into partial or full alignment with a low pressure discharge passageway opening in said one end cover and a low pressure inlet passageway opening in said other end cover, so that each said channel is alternately supplied with the high pressure first fluid through said one end cover and then with the lower pressure second fluid through said other end cover, the improvement which comprises oblique ramps in said high pressure inlet and discharge passageways in said end covers which cause directional flow of high pressure fluid into and out of said rotor channels to provide force that causes said rotor to revolve in a first angular direction, while said low pressure inlet and discharge passageways are devoid of any such ramps that would so direct flow to provide additive impetus to cause said rotor to revolve in the first angular direction.