GB545974A - Improvements in or relating to multi-cylinder internal-combustion engines - Google Patents

Abstract

545,974. Two-stroke and four-stroke engines. CORBITT, R. W. Dec. 19, 1940, No. 17918. [Class 7 (ii)] In a multicylinder in-line engine having one or more banks of separate cylinders and driving a rotatable mass unsymmetrically arranged in relation to the crankshaft, so that the mass and the crankshaft are liable to vibrate torsionally with a node outside the length of the crankshaft, the angular disposition of the cranks and the order of firing are such that torque impulses are applied to the crankshaft in simultaneous pairs at points equidistant from the mid-point of the crankshaft. In one form, Figs. 1 and 9, the engine has four banks of six cylinders, the banks A, B being at 60 degrees to each other and opposed to the banks C, D ; the crankshaft is symmetrical, with cranks 2, 5 at 240 degrees to the cranks 1, 6 and cranks 3, 4 at 120 degrees to the cranks 1, 6 and the firing order may be A1 and A6, B1 and B6, D3 and D4, C1 and C6, A3 and A4, B3 and B4, D2 and D5, C3 and C4, A2 and A5, B2 and B5, D1 and D6, C2 and C5. In modifications, (a) the engine has two banks of six cylinders at 60 degrees, or two opposed banks of six cylinders, the crankshaft being that shown in Fig. 9 ; (b) the engine has two opposed banks of cylinders and the crankshaft shown in Figs. 4 and 10, with crankangles of 0 degrees, 240 degrees, 120 degrees, 300 degrees, 60 degrees, 180 degrees, counting from crank 1; (c) the engine comprises two halfengines, each with two opposed banks of six cylinders, as shown in Fig. 5, the two crankshafts may be of the form shown in Figs. 1 and 9 or in Figs. 4 and 10, and one crankshaft may be inverted with respect to the other, as in Fig. 5, or may have its cranks at 30 degrees to those of the other. Suitable firing-orders are specified. Specifications 123,541, 322,161, [both in Class 7 (ii)], and 461,463 are referred to.