Patent ID: 6935300

Claim:
A rotary engine comprising a housing having a first and second intersecting cavity disposed therein, the first and second cavities including cylindrical wall surfaces; a rotor rotatably mounted in the first cavity, the housing and the rotor defining an annular chamber disposed therebetween, the rotor including a piston extending from the rotor into the annular chamber; a first valve rotatably mounted in the second cavity, the first valve having a circumference and recess sized to accommodate the piston during a rotation of the rotor; and at least one passage comprising an open portion formed in the cylindrical wall surface of the second cavity and an enclosed portion enclosed by the housing along a length of the enclosed portion, the open portion including a leading end and a trailing end with respect to a direction of rotation of the first valve and which open portion extends for at least about 20 degrees around a circumference of the cylindrical wall surface of the second cavity, and wherein the enclosed portion connects the open portion to the annular chamber downstream of the second cavity relative to a direction of rotation of the rotor.