Rotary intermeshing gear machine with pressure-balancing including resilient and non-extrudable sealing members

Claim 1

A rotary intermeshing gear machine including a casing having a low-pressure port and a high-pressure port, at least two intermeshing rotors housed for rotation in said casing, at least one end plate means associated with said rotors, a pressure-balancing arrangement associated with the end face of said end plate means remote from said rotors and with an adjacent face of said casing, said pressure-balancing arrangement including means defining a plurality of separate grooves provided in one of said faces and sealing means which comprise a plurality of resilient members, each of predetermined length and each disposed in a respective said groove, and which separate one from another a plurality of areas on that one face which are individually subjectable to differing fluid-pressures, lands being formed by the material of said one face which each separate a portion of one said groove from an adjacent portion of another said groove, and recess-defining means being formed in each of said lands, and a single non-extrudable element so located adjacent said resilient members by engagement with said grooves and with said recess-defining means that said reslient members are all in substantially full length engagement with said single element whereby together said element and members establish fluid-sealing between said end face and said adjacent face, and those portions of said element which engage said recess-defining means each forming a bridge crossing from a said portion of one said groove to an adjacent said portion of another said groove.