Rotary piston engine sealing mechanisms

Rotary piston engine including a casing which comprises a rotor housing having an inner wall of trochoidal configuration and a pair of side housings having inner walls and secured to the opposite sides of the rotor housing to define a rotor cavity in the casing, a rotor of substantially polygonal configuration having opposite side surfaces and disposed in said rotor cavity for rotation with apex portions in sliding engagement with the inner wall of the rotor housing, apex seal means provided in each apex portion of the rotor and comprising a sealing groove formed in the rotor at the apex portion to extend in axial direction of the rotor, an elongated sealing piece and an elongated support piece disposed in said sealing groove in a superposed relationship substantially throughout their lengths with said sealing piece faced to the inner wall of the rotor housing, spring means disposed between the support piece and the sealing groove to bias the sealing and support pieces toward the inner wall of the rotor housing, corner seal means provided in each side surface of the rotor at each apex portion, said corner seal means comprising a corner seal recess formed in the side surface at each apex portion, a corner seal member of one piece construction fitted to the corner seal recess and having an axially extending slit for receiving an end portion of the apex seal means and spring means for biasing the corner seal member toward the inner wall of the side housing, said slit of the corner seal member having a narrow portion of a width which is smaller than width of the sealing groove of the apex seal means and a wide portion of a width which is not smaller than the width of the sealing groove of the apex seal means, said narrow portion of said slit of the corner seal member being opposed to only one of the sealing and support pieces of the apex seal means with a slight clearance therebetween.