Sealing arrangement for rotary combustion engine

Claim 1

A rotary internal combustion engine having a peripheral housing and a pair of side housings defining an internal cavity and a rotor rotatably mounted within the cavity, the rotor having a plurality of apex portions with a sealing arrangement positioned in a slot at each apex portion to sweep the inner surface of the peripheral housing and the inner faces of the side housings in sealing relationship, wherein the improvement comprises: a. The inner peripheral surface being formed of a harder material than the inner faces of the side housings; b. each sealing arrangement comprising a middle part and two end parts; c. the middle seal part being generally trapezoidal and having a long side disposed radially outwardly and sweeping the inner peripheral surface, a shorter side parallel with the long side and disposed radially inwardly, and two short ends slanting from the long side to the shorter side; d. the two end parts each being generally trapezoidal and having a short side disposed radially outwardly and sweeping the inner peripheral surface, a longer side parallel with the shorter side and disposed radially inwardly, one end perpendicular to the short side and to the long side and sweeping the adjacent side housing, and an opposite end slanting from the short side to the longer side and juxtaposed in mating relationship to the slanting end of the middle seal part in such a manner that the sealing assembly of the three seal parts has a generally rectangular outline; e. the middle seal part being formed of a harder material than the end seal parts but less hard than the inner peripheral surface of the housing; f. the end seal parts being urged resiliently outwardly and exerting a wedging action outwardly against the middle seal part to maintain the radially outward edges of the three seal parts in sealing contact with the inner peripheral surface with seal wear thereagainst being preferentially absorbed by the end seal parts.