Rotor with a hydraulic overbalancing recess

In a rotary pressure device for use in one of a hydraulic pump and motor application including:

• a housing member including a first fluid path and a second fluid path, one of said first and second fluid paths adapted for conducting high pressure fluid;
• a manifold assembly having a first fluid passage fluidly connected to one of said housing member first and second fluid path, a second fluid passage fluidly connected to the other of said housing member first and second fluid paths, with one side of said manifold assembly adjoining said housing member;
• a gerotor set having an internally toothed stator member, and an externally toothed rotor member, eccentrically disposed within said stator member, said rotor member having an internal bore, a first axial end surface adjoining another side of said manifold assembly, and a second axial end surface, said rotor member being hydraulically balanced relative to said stator member;
• a channeling plate having a first side adjoining said gerotor second axial end surface and a second side;
• an end plate having a first side adjacent said channeling plate second side;
• and
• a cavity between said channeling plate and said end plate for receiving high pressure fluid, wherein the improvement comprises:
• a. first routing means in said gerotor set and said channeling plate for operatively providing high pressure fluid from one of said first and second fluid paths to said cavity;
• b. second routing means in said channeling plate for operatively providing high pressure fluid from said cavity to a recess in said second axial end surface of said rotor;
• and said high pressure fluid within said recess being used as the means for overbalancing said rotor member and thereby biasing said rotor toward said manifold assembly.

A rotary fluid pressure device comprising:

• a housing member defining a fluid inlet port and first flow passage for receiving one of a high pressure fluid and an exhaust fluid, a fluid outlet port and second flow passage for receiving the other of the high pressure fluid and the exhaust fluid, and an internal bore for receiving one of the high pressure fluid and the exhaust fluid;
• a manifold assembly having a first fluid passage, fluidly connected with said housing member first flow passage, for receiving one of the high pressure fluid and the exhaust fluid, a second fluid passage, fluidly connected with said housing member second flow passage, for receiving the other of the high pressure fluid and the exhaust fluid, and an internal bore, fluidly connected with said housing member internal bore, for receiving one of the high pressure fluid and the exhaust fluid;
• a gerotor set having an internally toothed stator member with at least one axial fluid path extending therethrough, fluidly connected with said manifold assembly first flow passage, for receiving one of the high pressure fluid and the exhaust fluid;
• and an externally toothed rotor member hydraulically balanced relative to said stator, said rotor member eccentrically disposed within said stator member, having an internal bore, fluidly connected with said manifold assembly second fluid passage, for receiving the other of the high pressure fluid and the exhaust fluid, said rotor member also including a first axial end surface, and a second axial end surface, said second axial end surface including therein a recess circumferentially surrounding said internal bore for receiving the high pressure fluid, said rotor member additionally including a plurality of axially extending through holes for receiving one of the high pressure fluid and the exhaust fluid, with one side of said gerotor set adjoining another side of said manifold assembly;
• a substantially rigid channeling plate having a first side, a second side, a first fluid passage, fluidly connected with said stator member at least one axial fluid path, said first fluid passage extending through said channeling plate for receiving one of the high pressure fluid and the exhaust fluid, said channeling plate also including a second fluid passage, fluidly connected with said rotor internal bore, said second fluid passage also extending through said channeling plate for receiving the other of the high pressure fluid and the exhaust fluid, said channeling plate additionally including a plurality of through holes, fluidly connected with said rotor second axial end surface recess, for receiving the high pressure fluid;
• an end plate having a first side adjacent said second side of said channeling plate;
• and
• a cavity, fluidly connected with said plurality of through holes in said channeling plate, located between said channeling plate and said end plate for receiving the high pressure fluid from one of either said channeling plate first and second fluid passages.