Seal compensated geometry rotary motion device

摘要

Conventional industry practice has been to provide apex seals along adjoining intersecting peripheral surfaces of the envelope members in trochoidal rotary devices. The trochoidal member profiles are then recessed by a seal offset amount and the seals extended from the apices of the envelope member by the seal offset amount to minimize reciprocation of the seals in their grooves. In accordance with the invention, modified epitrochoids and corresponding envelopes are formed so that sealing faces of the apex seals can be substantially continuous with the envelope peripheral surfaces. In this manner, nearly ideal expansion ratios are achievable in such rotary devices and wider sealing faces can be used than heretofore practical.