Gerotor machine with commutating valving through the ring gear

摘要

The invention relates to a fluid pressure operated motor or pump of the type having a gerotor displacement mechanism which normally includes inner and outer wheel and ring gears which in operation have relative rotational and orbital movement therebetween. Such devices inherently have a form of valving wherein, with a commutating type of action, fluid is directed from the casing inlet to expanding chambers of the gerotor and directed from collapsing gerotor chambers to the casing outlet. Two embodiments are presented in which the first has the casing thereof fixed in space. In both units the commutator valving includes valving patterns in two valve plates attached to opposite sides of the casing and in the wheel gear which has orbital movement relative to the casing. The commutating valving arrangement has control ports on opposite sides of the unit for feeding and exhausting motive fluid to and from the unit and auxiliary ports on opposite sides of the unit to balance or equalize the pressure forces on each side thereof. Bolts are used for fastening the tightening together the casing side plates. These bolts are also used as guides for the orbital path of the ring gear and holes are provided in the ring gear to accommodate the bolts.