GB905112A - Two-stroke-cycle internal combustion engine - Google Patents

Abstract

905,112. Lubricating. AMERICAN BRAKE SHOE CO. July 14, 1959 [July 16, 1958], No. 24128/59. Class 12 (3). [Also in Group XXVII] A two-stroke engine 10, Fig. 1, includes a lubrication chamber with a lubrication well 83, an oil reservoir 17, and a pair of check valves 88 and 96 interconnecting the reservoir and the well at different levels to maintain a substantially constant oil level within the well, the valve 88 having a metering orifice 86 for dispersing the oil in a spray within the chamber. Crank-shaft rotation causes a spring-loaded valve plate 27 to rotate and close the inlet port to a transfer passage 28. Continued rotation causes an upward piston movement and a reduction in pressure within the chamber 16. Oil, from the reservoir 17, is injected past the spring-loaded check valve 94 through the metering orifice 86 into the well 83 and is sprayed upwardly into the chamber 16 and a finger 85 fixed to the crank-pin further disperses the oil within the chamber. When the piston 47 approaches its T.D.C. indicated at 47A, a port 68, in the valve plate 27, allows a charge of fuel-air mixture to be drawn into chamber 16 through the conduit 59 and the separator barrier 71, of a rotary oil filter 63. Downward movement of the piston 47 increases the pressure in chamber 16 and a charge of fuel/air mixture is forced through the separator barriers 71 and 81 and transfer passages 29, 42 into the combustion chamber 53 whilst any excess of oil in the well 83 is forced out through an opening 87 and past the spring-loaded check valve 96. In a modification, Fig. 6, a check valve 188 has a hinged vane 193 which serves as a closure member for the opening 193, and a separate metering orifice 86 is included in the valve housing 192. A similar valve may replace the drain valve 96 of Fig. 1. The bearing sleeves 21, 34 may be replaced with ball or roller-bearings and gaskets may be interposed between crank-case sections 13, 14 and 15. The finger 85 provides further splash lubrication on the piston downward stroke. A labyrinth oil seal is formed by lands 100, on the rotary separator portion 66, and grooves 100 on the adjacent crank-case wall. The labyrinth seal may be formed with V, truncated V, sinusoidal or rectangular lands and grooves and axial adjustment of the gap between the lands and grooves may be provided, e.g. by shims or spacers. Specification 733,743 is referred to.