GB1392174A - Rotary internal combustion engines - Google Patents

Abstract

1392174 Rotary positive displacement machines SVENSKA ROTOR MASKINER AB 30 March 1972 [17 March 1971] 7079/71 Heading F1F A rotary internal combustion engine comprises a power rotor 54 having lobes 76 and interspaces 78 which intermesh with the grooves 66 and lands 58 of a rotary abutment member 56. A casing 20 has two cylindrical chambers 24, 26 which coaxially house the respective rotor 54 and abutment member 56, each lobe 76 of rotor 54 being disposed outside the rotor pitch circle and each groove 60 being disposed inside the abutment member pitch circle. Each lobe 76 has convex flanks 80,82 joined by a tip portion 84 coaxial with rotor 54 and each groove 60 is defined by concave flanks 62,64 joined by bottom portion 66 coaxial with member 56. Flanks 80,82 are epitrochoidal, being generated by the outer edges 70,72 of the lands 58. Passages 40,42,44,46 are fresh air inlet ports, ports 48 and 50 being used for scavenging and ports 49 and 51 for the exhaust of combustion products from interspaces 78 and grooves 60. Port 52 injects fuel. The various dimensions and angles C A , C R , R A , R R , D C , L, α, # and γ are critical within predetermined limits, α should be between 65 degrees and 80 degrees, L should be greater than 75% of C A , the total number of grooves 60 and lobes 76 should be less than ten, and there should be more grooves 60 than lobes 76, the difference being limited to a maximum of three. A part-spherical cavity 74 should be formed in portion 66 of groove 60. In operation, air is taken into interspace 78 and groove 60 through ports, 40, 42 and 44, 46. The interspace 78 and groove 60 are each then isolated when the following lobe 76 or land 58 engage the respective walls 36, 38 of the chambers 24, 26. Shortly after this, the leading land 58 of the groove 60 projects into the interspace 78 and compression begins, combustion fuel being fed through port 52. Compression continues until maximum intermesh occurs, as shown in Fig.1. At this point ignition occurs, being effected by sparking plugs in the rotor lobe tip and cavity 74 Fig.3 (not shown). Expansion then commences, the interspace and groove, 78, 60 finally separating again before respective discharging their combustion products through exhaust ports 49, 51.