GB578638A - Improvements in or relating to two-stroke cycle internal combustion engines - Google Patents

Abstract

578,638. Two-stroke engines; lubricating. WAERN, B. A. De. April 5,1944, No. 6337. [Class 7 (ii)] In a two-stroke engine with crank case compression, a pump cylinder 19 having a piston driven from the driving gear of the main piston assists by its inner side the crank case compression and by its outer side compresses a further charge into a receiver 25 which has valve-controlled communication with the combustion chamber. The main piston 8 draws in its charge through a non-return valve 21 and the compressed charge is transferred to the combustion chamber by a passage 43. The compression of the supplementary charge which, in a gas engine, may be gas, is controlled by valves 23, 24 and its delivery by a valve 26 or by piston-controlled ports. The pump cylinder 19 may be duplicated by arranging two pistons driven from cranks on the main crank shaft on either side of the main crank and in a two cylinder engine the two pump cylinders may be arranged at either end of the crank shaft. By this arrangement, the inertia forces are counterbalanced. Lubricant is delivered by a pipe 37, Fig. 4, to a recess 41 in a flange on the main shaft and thence it passes by a passage 39 to the crank pin 12 carrying the pump connecting rod. A flange 31 throws lubricant through a shield 30 to a channel 34 leading to the main crank pin. A pipe 40 also supplies lubricant to the main crank pin through an annular flange 36 and a channel 35. The pump crank pin may be formed as an eccentric and in this case, lubricant from the pipe 37 enters an annular recess therein the width of the driving gear being reduced thereby. The upper part of the crank case may be formed as storage chambers for lubricant after removal from the crank case and purification, the lubricant flowing back to the pipes 37, 40 by gravity.