GB171449A - Improvements in and relating to counterbalanced crank shafts - Google Patents

Abstract

171,449. White, A. E., (Park Drop Forge Co.). Aug. 6, 1920. Crank-shafts.-Relates to crank-shafts of highspeed engines on automobiles and aeroplanes &c., of the kind provided with balancing discs or weights shrunk on or otherwise secured so as to be concentric with the shaft, and comprises an arrangement wherein a balancing-ring provided with an integral counterweighting-arm is shrunk on to the crank part, interlocking engagement being provided between such parts to prevent relative movement. Forms of crank arms used in four-throw and six-throw crank-shafts are shown in Figs. 3, 4, and 5, the balancing-ring 30 in each case having an integral counterweighting-arm 31 with an engaging surface 35 preferably in the form of an obtuse V shrunk on to the correspondingly-shrunk crank part, such as shown at 17, 27, 14, which is gripped between the engaging surface 35 and a preferably similarly formed thin portion of the rim, such thin part being soldered or torch-welded to secure the parts permanently. To prevent lateral displacement, the surface 35 and the co-operating crank part are formed with V-shaped grooves and ribs as indicated at 36 in Fig. 6. The balancing-rings are passed over the shaft end into their respective positions, the inner surface of the rings being slightly inclined, if desired, to facilitate passing over the crank webs. The fan-shaped formation of the counter-weighting arms 31 is stated to increase the effectiveness of the balancing for increases or decreases of the normal speed.