INTERNATIONAL COMBUSTION ENGINE

Hokitika Guardian, 14 February 1931, Page 6

INTERNATIONAL COMBUSTION ENGINE

NEW PRINCIPLE, i NEW ZEALANDER’S INTEREST. LONDON, December 10. A new development of the internal combustion engine has been demonstrated at the .Reliance Engineering Works, Hither Green. Reside its general interest, it has some New Zealand interest as Mr James F. Nelson, of -‘Rouuienl.” Havelock North, met the inventor. Mr Robert Rodger, of Lewisham, Loudon, when lie was in this country. Mr Nelson was so taken with the model that he bought a financial interest in the venture, and became a partner of the inventor. Mr Rodger has been developing the engine, for a good many years, and he has now produced a simple machine, on rather different principles from those already in use, and which combines simplicity and power with cheapness. A 20 h.p. engine should oe made to show a profit at £"2o. The general principles are applicable to petrol or heavy oil. The design consists of a single-cylinder two-stroke cycle engine with an integral supercharger, and a single reciprocating sleeve for the control of the inlet and ! exhaust gases. |

The cylinder has inlet parts around the barrel near the top, and the exhaust outlets are situated on a line encircling the barrel a little below the lateral centre. The sleeve has ports cut in it, the number of apertures and the length of each corresponding

with those in the cyclinder. An eccentric on the crankshaft controls the motion of the sleeve; the eccentric lags behind the crankpin by GO degress —that is to say the crankshaft is 60

degrees past top dead centre when the, sleeve is at top dead centre.* A plain type of piston is employed, no deflector head being required. The cylinder head carries the sparking plug or fuel-injection nozzle; water cooling is used for this part. CYCLE OPERATIONS. Principal interest centres in the cycle of operations. To start the engine the crankshaft is rotated by hand or by an electric motor in the usual manlier; the supercharger, which is permanently in operation, delivers earbur. etted mixture through a special bypass valve to the combustion space. When the exhaust ports have been closed, compression commences. and the spark occurs in the ordinary way. somewhat before top dead centre. After the occurrence of the spark the gases continue to expand until the piston is slightly before bottom dead centre. The exhaust ports in the

■sleeve then begin to come into regiser with those in the cylinder barrel; the piston passes bottom dead centre and forces gas out of the cylinder into the passages in the easting. As the piston rises the sleeve lags hv 60 degrees; next the inlet ports begin to open, and the gas, under pressure I rom the blower, enters the cyclinder. forcing downwards any exhaust gas in the upper part of the barrel—Dip ex-

haust ports are still open slightly. Advancing a stage farther, the piston in its upward travel, closes the exJiaust ports, and then compression begins—the mixture is already under pressure, which is controlled by the initial pressure at the time of inlet to the cylinder and the timing of the exhaust ports. Ignition occurs just before top dead centre, and the cycle is complete. THE EXPANSION STROKE. Probably the most outstanding feat-

tire of the machine is that the compression stroke occupies only about 90 degress of crank travel, whilst the expansion stroke continues through j 160 degrees. I No reliance is placed upon ornnk- ; case compression for forcing the gas >mto the combustion space; this work ■ is performed by the blower, which may I he driven at any desired speed. 1 Simplicity is a marked feature of the

design ; this of course, should lie reflected in manufacturing cost. The i sleeve is directly operated through an eccentric; all the sleeve-driving gear is therefore easily lubricated, being situated in the crankcase. The great length of the expansion stroke in comparison with the compression stroke should make for fuel economy. The principle may he used (or multi-cylindered engines, and may h<* applied to vehicles or for stationary work. It is possible that its greatest scope is in connection with the Diesel engine, to which so much attention is now being paid.