Internal seal for rotary piston combustion engine

Abstract

The invention relates to an internal seal for rotary piston combustion engines of the trochoid type in which a housing consisting of two end pieces and a multiarcuate shell contains a polygonal piston rotatably mounted on an eccentric. At least one sealing ring conconcentric with the piston axis of rotation is disposed in a recess of the piston in each of its two end faces. The ring is pressed by spring means against the adjoining end piece and is sealingly and slidably engaged therewith to prevent passage of coolant or lubricant into the working chambers. The seal between the sealing ring and a wall of the recess in the end face of the piston is effected by an elastic ring.

I claim: 
     
       1. An internal seal for rotary piston combustion engines of the trochoid type having a housing of two end pieces and a multi-arcuate shell in which a polygonal piston is rotatably mounted on an eccentric, the piston having at least one sealing ring concentric with its axis of rotation in a recess on each of its two end faces the sealing ring being pressed by spring means against the adjoining end piece and sealingly slidable thereon, said sealing ring having .[.a.]. .Iadd.an inner .Iaddend.surface parallel to .Iadd.and spaced from .Iaddend.a wall of said recess and means for establishing a seal between said .Iadd.inner surface of said .Iaddend.sealing ring and said wall the improvement which comprises as the means for establishing said seal; a spring metal ring, C-shaped in cross-section, interposed .Iadd.in the space .Iaddend.between said .Iadd.inner .Iaddend.surface and said wall and abutting each of said .Iadd.inner .Iaddend.surface and said wall along continuous lines of contact, said C-shaped ring .[.forcing.]. .Iadd.sealing the space between .Iaddend.said sealing ring .Iadd.inner .Iaddend.surface .[.against.]. .Iadd.and .Iaddend.said recess wall. 
     
     
       2. An internal seal according to claim 1, wherein the C-shaped ring .[.15.]. is provided on its outer surface with a friction reducing, heat resistant coating compensating for equalizing minor tolerances and irregularities. .[. 
     
     
       3.  An internal seal according to claim 1 wherein the C-shaped ring is arranged between the outer surface of the sealing ring and the adjacent wall of the recess with means being provided for holding the C-shaped ring in position..]. 
     
     
       4. An internal seal according to claim 1, wherein the sealing ring has an L-shaped cross section defined by the axial flange and the radial flange forming an angle open radially inward by the C-shaped ring being arranged with the angle. 
     
     
       5. An internal seal according to claim 1 wherein the sealing ring has flanges forming an angle open radially outwardly in which the C-shaped ring is arranged. 
     
     
       6. An internal seal according to claim 1 wherein the spring means is a corrugated spring ring, bearing on one side against the bottom of the recess and on the other side by way of the C-shaped ring against the sealing ring to press the sealing ring against the associated end piece.