Patent ID: 6884048

Claim:
A rotary fluid pressure device of the type including housing having a fluid inlet port and a fluid outlet port; fluid pressure-operated displacement means associated with said housing, and including an internally-toothed ring member, and an externally-toothed star member eccentrically disposed within said ring member for relative orbital and rotational movement therebetween to define a plurality of expanding and contracting fluid volume chambers in response to said orbital and rotational movements, and minimum and maximum volume transition chambers; a valve member cooperating with said housing to provide fluid communication between said inlet port and said expanding volume chambers and between said contracting volume chambers and said outlet port; said valve member and said housing cooperating to define a nominal valve overlap; said device being wherein the improvement comprises: a first oil passage with relatively high pressure fluid therein surrounding the gear set, a plurality of second oil passageways connecting the first oil passageway to the expanding and contracting oil chambers, and fluid non-return valves in each of the second oil passageways to permit the flow of oil therethrough only in a direction to the first oil passageway from the oil chambers.