Patent GB-1115310-A (GB)
Title: Planetary piston internal combustion engine of the trochoidal type, especially for forming the power unit of a motor vehicle
IPC: F02B53/00
Filed: 1966-12-09
Abstract: 1,115,310. Rotary-piston internal combustion engines. NSU MOTORENWERKE A. G. and WANKEL G. m. b. H. Dec. 9, 1966 [Dec. 10, 1965], No. 55133/66. Heading F1F. A rotary-piston I. C. engine of the kind having a three-sided piston planetarily rotatable within a housing comprising a peripheral wall whose inner surface is of two-lobed epitrochoidal profile, includes in combination a liquid-cooled housing whose major axis is or nearly horizontal, a piston cooled by the passage therethrough of the incoming gaseous mixture prior to its entering the working chamber of the engine, an ignition means located above the major axis of the housing in a zone that is nearest to said axis, an exhaust port which meets the outer surface of the housing peripheral wall below the said axis in a zone that is nearest to said axis and an inlet passage extending to the inlet port located in one of the end walls from a point on the outer surface of the housing which lies above the said axis. The invention is described as a twin-unit automobile engine comprising an output shaft 9, Fig.1, mounting on a pair of 180 degree spaced eccentrics 10, 11, pistons 14, 15 which planetarily rotate within a housing comprising peripheral walls 1, 2, external end walls 3, 4 and a common intermediate wall 5. At one end of the shaft 9 a flywheel 20 is fitted with a peripheral counterweight 21 and at the other end thereof a gear wheel 24 drives through a toothed belt (28), Fig. 2 (not shown) a contact breaker 29, Fig. 4, a fuel pump 30 and an oil-metering pump (31) mounted within an oil reservoir 31a and a pulley 23 driving through a Vee belt 25 a generator 26, water pump 27 and fan 27a. The oil reservoir 31a is mounted on the engine housing adjacent the "hot zone" to ensure free flowing oil. Sparking plugs 41, one for each unit, are fitted above the major axes 60 adjacent axis near zones and exhaust connections 43, one for each unit, below the axes 60 near the other axis near zones. Preferably the axes 60 are inclined at 15 degrees so that the axes of the exhaust pipes 61 are above the lowest point of the housing to improve ground clearance. Fuel with a metered quantity of oil passes to the carburetter and on being mixed with air, enters an intake passage 34 positioned above the axes 60 in the "cold region" of the intermediate wall 5. The mixture then flows through the passage 34, openings 36, 37 in the pistons and hollow spaces 38, 39 in the end walls 3, 4 before passing through inlet ports in the side faces of these walls into the engine working chambers. Cooling water for the housing enters an inlet 50 and flows to the water pump 27, from there it circulates through cooling spaces 53 in the peripheral walls 1, 2, cooling spaces 53a in the end walls 3, 4 and intermediate wall 5 and thence over a thermostat 52 to an outlet opening 58. When the engine is over-cooled during the warm-up period the thermostat 52 closes the outlet opening 58 and opens a short-circuit passage 51 to re-circulate the water.