GB541409A - Improvements relating to the scavenging of two-stroke sleeve valve internal combustion engines - Google Patents

Abstract

541,409. Cylinder ports and passages. KAMMER, G. S. April 23, 1940, No. 7331 and 9850. [Class 7 (ii)] Scavenging of two-stroke sleeve valve engines is assisted by arranging the admission ports at or near the bottom or outer end of the cylinder,and the exhaust ports between the admission ports and the inner end of the cylinder, both sets being distributed all round the circumference. Fig. 1 shows an engine with a sleeve valve 3 arranged in line with a short liner fixed at the inner end of the cylinder, the upper edge of the sleeve controlling exhaust ports 6, while admission ports 4 for air or mixture are controlled by ports 11 in the sleeve and by the piston. The exhaust passages 7 lead to an annular receiver 8 and may diverge outwardly as shown, or may slope downwards and outwards. The inlet passages 4 may be tapered and sloped in the same way as indicated in Fig. 7, or may have an abrupt change in section as shown in Fig. 1, the passages in either case communicating with an annular receiver 9 supplied through a duct 10 from a blower 5. In modifications the sleeve valve may operate between a cylinder liner and an extension of the crank case. Scavenging is effected in the manner indicated by the arrows in Fig. 7, the cylinder head being shaped as there shown, or as shown in Fig. 1, to facilitate the flow. The partitions dividing the exhaust ports around the cylinder may be inclined so that the rebound of the exhaust gases, upon reentering the cylinder, will cause a whirling movement of the air or mixture being admitted. The exhaust may be led away to a turbine. Specification 506,326 is referred to.