GB984773A - Cooling rotary piston engines - Google Patents

Abstract

984,773. Rotary-piston internal combustion engines. NSU MOTORENWERKE A.G., and WANKEL G.m.b.H. Jan. 31, 1962 [Feb. 10, 1961], No. 3595/62. Heading F1F. In a rotary piston I.C. engine working on a four-stroke cycle and of the trochoidal type, the piston 7, Fig. 2, is formed with a plurality of internal chambers 13 communicating through coolant supply ducts 14, Fig. 1, with an annular reservoir 15 in the piston fed from a duct 16 and through drain ducts 17 with a coolant collecting cell 18 formed in the piston. The reservoir 15 is sealed on its outer periphery by a resilient seal ring 22 carried by the piston and the ducts 14 open into the chambers 13 at the outer radial extremity thereof. Radial ducts 19a formed in a fixed plate 19 collect the coolant from the cell 18 and pass it to return ducts. During the rotation of the piston and its planetary movement around the inner contour 8 of the housing, the acceleration forces change in direction so that the coolant is first forced through the ducts 14 into the radially outward portions of the chambers 13 and thence inwardly to pass out through the drain ducts 17. In a modification, the collecting cell may be formed in the end face of the housing instead of in the piston. A seal ring similar to the seal ring 22 is then fitted on the other end face of the piston to prevent the leakage of coolant between the piston and the adjacent and face of the housing. In a further modification, a further seal ring radially outwards of the seal ring in the said other end face of the piston is fitted. Any coolant passing the inner seal ring is then collected in an annular piston chamber and returned to the collecting cell. Specification 893,938 is referred to.