GB1155803A - Crankshafts - Google Patents

Abstract

1,155,803. Crank-shafts. SULZER BROS. Ltd. 31 Jan., 1968 [8 Feb., 1967], No. 5031/68. Heading F2U. Oil supply ducts 4, 5, 9, between the main journals 3 and crankpins 1 of a crank-shaft for internal combustion engines having cylinders arranged in a V with two connecting rods carried on each crankpin 1, are positioned for minimum stress concentration at the crankpin faces, and to facilitate drilling. As shown, crossing bores 5, drilled from bevelled faces 6 on opposing crankwebs 2, link diametrical bores 4, in the main journals 3, with outlet bores 9 to the crankpin surfaces, the bores 9 each consisting of two bores angled to each other (Fig. 3) to intersect the lower of the crossing bores 5 and form surface outlets 8 on the crankpin centre line of Fig. 1. The crossing bores 5 may, as shown, intersect such that the connecting rods can be lubricated from one main bearing only in an emergency, alternatively, the bores 5 may cross without communicating. In Figs. 4 to 6 (not shown) the outlet bores (21), (Fig. 6) in the crankpin 1 are formed diametrically, the admission bores (22), (Fig. 5) in the main journals each consisting of two bores angled to each other whereby the linking bores (20) are further from the transition (23) of the crankwebs 2 and crankpin 1 to lower stress concentration at this point. Alternatively, both the admission bores 4 in the main journals 3 and outlet bores 9 in the crankpin 1 may each be formed as two bores angled to each other for greater strength, or may each be formed diametrically for simplicity.