GB1227576A - - Google Patents

Abstract

1,227,576. Reciprocating pumps. CATERPILLAR TRACTOR CO. July 17, 1968, No.33996/68. Heading F1A. [Also in Divisions F2 and G3] In an internal combustion engine injection or ignition timing device, adjustment is controlled by oil pressure centrifugally generated in a vortex chamber. An axially fixed rotating cam-shaft 12, Fig. 1, of an injection pump 11, is coupled by a helical spline connection 21 to gear 16 engaging an engine drive gear 17; a cavity 24, disc 26 and flexible diaphragm 27, define a vortex chamber in the gear 16, into which oil 53 may be introduced by way of bore 31 and passages 43 from chamber 48. A rod 28 fixed to 26 extends through bores 31, 32 and a spring 34 acts on flange 36 to force the rod and gear 16 toward cam-shaft 12, and oil continuously admitted to chamber 48 acts against surface 49 to urge the gear 16 away from cam-shaft 12; at constant speed these forces balance. Increasing the engine speed increases the centrifugal force on the oil 53 which exerts a greater pressure against 26 moving rod 28 away from cam-shaft 12, as this occurs a section of rod 28 having reduced diameter acts with control edge 42 of bore 31 to reduce the flow of oil from chamber 48. Thus increasing the oil pressure acting on 49 and moving gear 16 away from shaft 12, and the rotation imparted to 12 causes advancement of the timing. Decrease in engine speed reverses the action. In another embodiment Fig.2, an axially movable cam-shaft extension 61 is coupled by helical spline connections 64, 59 to an axially fixed drive gear 63 and a pump cam-shaft 58, and extends through the drive gear to bear against a spring 74. Fluidpressure generated in the vortex chamber defined in the drive gear 63 acts against a disc 76 which is carried by the shaft 61, thus causing axial movement of 61 and rotation of the cam-shaft 58.