Patent GB-277790-A (GB)
Title: Improvements relating to combustion-product and like engines
IPC: F02B75/18
Filed: 1926-08-18
Abstract: 277,790. Tait, R., and Tait, D. M. Aug. 18, 1926. Compound or multi-stage piston pumps; actuating by fluid-pressure motors; valves, arrangement of; valve gear. . -In a compound combustionproduct or like engine, a charge of air is compressed in stages in the engine, and is then mixed with fuel, combustion is effected at high pressure, and the products of combustion, with or without admixture with steam, are utilized in two or more stages in the engine during the stage compression of the air therein. The engine may be single or double acting and may work on a two-stroke or a four-stroke cycle. Figs. 1 to show a compound doubleacting two-stroke engine in which the fluid is expanded and the air is compressed in three stages, combustion taking place in a chamber 4 constructed as described in Specification 279,197, [Class 123 (ii). Steam generators]. The engine comprises high-pressure, intermediatepressure, and low-pressure cylinders HP, IMP, and LP and a double-acting scavenging pump 20 in line with the cylinder LP, the pistons of the pump 20 and the cylinder LP being mounted on a common piston-rod. The pump 20 discharges into a low-pressure air reservoir 22 communicating with a row oi ports 23 at each end of the cylinder LP, controlled by a reciprocating and oscillating sleeve valve 24, which also controls air outlet, ports 29 and pressure-fluid inlet and exhaust ports 32, 28. Corresponding ports on the cylinders IMP and HP are controlled by similar valves. The air entering the cylinder LP is deflected by baffles 34 and by the piston and sweeps out the pressure fluid. From the cylinder LP it passes by a transfer passage 30 and intermediate-pressure reservoir 22a to the cylinder IMP by a transfer passage 30<a> and reservoir 22<b> to the cylinder HP and through transfer passages 30<b>. 13<a> and a stop valve 31 to the airinlet passage 13 of the combustion chamber 4. The air in the cylinder HP may be compressed in two stages, first to a pressure of about 500 atmospheres, when the sleeve valve opens tn allow the greater part of the air to be expelled into the chamber 30<b>; the sleeve valve then closes, the remaining air being further compressed and excelled into a high-pressure reservoir supplying air for injecting atomized fuel and water into the combustion chamber 4 of the generator. A pressure fluid consisting of a mixture of combustion products and saturated air or steam passes from the chamber 4 through a baffle chamber 10 and passage 12 to the inlet ports 32<b> of the cylinder HP. From the exhaust ports 28<b> of this cylinder, the fluid passes to the cylinder IMP, LP by transfer passages 33a, 33 and is exhausted at 45, or may be expanded another stage. The cylinders are cast en bloc in two horizontal halves connected by a spigot joint 51 and secured by bolts 55 to standards 52 and the cylinder 53 of the scavenging pump and to a crank case 54, the standards 52 and cylinder 53 being cast in one piece. The sleeve valves 24 are each actuated from a pair of eccentrics on the crank-shaft through linkage gear shown in Figs. 1 and 2. The link 46 actuates a spindle 43 sliding within a sleeve 42 and rigidly connected at its upper end to a clip-bolt 47 which clamps the ends of the sleeve valve whilst allowing it to rotate. The valve is oscillated by the sleeve 42, which carries a pinion 44, engaging teeth 35 on the valve, and a pinion 41 engaged by a rack 40 oscillated by a lever 36 pivoted at, 37, an extension 36<a> of the lever being connected to a slide block 38 in the link 39. The links 39, 40 are connected by levers 48, 49 to a control shaft 50 adjustable by hand for regulating or for starting, stopping, and reversing. In a modification, the valve is rotated continuously through a shaft driven from the crank shaft. In a four-stroke engine, the valves are similarly actuated from a side or overhead half-speed shaft driven from the crankshaft; the pressure fluid is expelled from the cylinder on the first return stroke of the piston, and compressed air is admitted on the following stroke, further compressed on the fourth stroke, and discharged prior to the admission of pressure fluid on the next cycle.