Patent GB-663296-A (GB)
Title: Improvements in or relating to reciprocating internal combustion engines operating on the two-stroke cycle
Inventor: SAMMONS HERBERT
IPC: F02B33/00
Filed: 1949-04-11
Abstract: 663,296. Centrifugal and axial-flow compressors; motor power plant. NAPIER & SON, Ltd., D. March 27, 1950 [April 11, 1949], No. 9768/49. Classes 110(i) and 110(iii) [Also in Group XXVII] In a two-stroke engine of the kind having three parallel crankshafts in crankcases B, B<SP>1</SP>, B<SP>2</SP>, Fig. 4, interconnected by cylinder blocks C. C<SP>1</SP>, C<SP>2</SP> with two pistons in each cylinder thereof connected respectively to the adjacent crankshafts and controlling respectively inlet and outlet ports in the cylinder wall, a multistage axial flow compressor F, Fig. 1, for supplying air directly or indirectly to the inlet ports is housed partially or wholly in the approximately triangular space enclosed by the blocks C, C<SP>1</SP>, C<SP>2</SP> and crankcases B, B<SP>1</SP>, B<SP>2</SP>. As shown, the compressor F draws air through an inlet F<SP>1</SP> at the front end of the engine and feeds it through an annular passage F<SP>5</SP> to a centrifugal compressor G which delivers through three volutes such as G<SP>6</SP> to split inlet manifolds such as E<SP>2</SP>, E<SP>3</SP> supplying a ring of inlet ports in each cylinder. The compressor F is permanently drivingly connected to an exhaust-driven turbine K<SP>1</SP>, a transmission coupling L on the turbine rotor K<SP>4</SP> having an internally toothed coupling member always engaging a meshing coupling member on a shaft H permanently coupled to the rotor shaft F<SP>2</SP> of the compressor F. A second coupling member also permanently meshing the internally toothed member of the coupling L is fast with one element of a hydraulic clutch M<SP>2</SP>, the other element of which is fast with the rotor G' of the compressor G. The clutch M<SP>2</SP> is of the kind which can transmit torque in both directions of power flow, and may be of the permanently filled type or, preferably, of the type the filling of which can be controlled to render it operative or inoperative. The rotor G<SP>2</SP> has a gear J connected by independent but similar gearing trains to two of the engine crankshafts. One such train is shown leading to a gear J<SP>10</SP> on a crankshaft A and incorporating a flexible shaft J'. The turbine K' is fed from a ring of exhaust ports in each engine cylinder, through manifolds D<SP>1</SP>, three volutes such as N' and an annular chamber N<SP>3</SP>. The whole arrangement is such that. at starting, the compressor G supplies air to the engine and, if the clutch M<SP>2</SP> be operative, the compressor F is also rotated to reduce or eliminate air drag therethrough. In normal operation under load. the turbine K<SP>1</SP> powers the compressor F and, if the clutch M' be operative, any excess turbine power passes to the compressor G and, if more than sufficient to drive the latter. to the appropriate engine crankshafts. The three crankshafts are intergeared to an output shaft C<SP>7</SP> so that one rotates oppositely to the others, the relative phasing being such that, in each cylinder, the two pistons are 20 degrees out of phase, the inlet and exhaust ports being so arranged that the latter open before the former and close simultaneously with or after them. The cylinders are water-cooled. The engine may be constructed in the manner described in Specification 660,411, [Group XXVII]. According to the Provisional Specification, the centrifugal compressor may be connected by flexible shaft gear drives to all three crankshafts.