GB721727A - Improvements in or relating to means for varying the angular relation between driving and driven shafts - Google Patents

Abstract

721,727. Rotary engines. LANOVA CORPORATION. Oct. 23, 1952 [Nov. 6, 1951], No. 26645/52. Class 110 (2). [Also in Group XXIX] In a rotary-vane motor for varying the angular relation between a driving shaft 36 and a shaft 22 driven thereby, separate inlet and outlet ducts are provided to effect relative movement of the vanes 82 and the motor casing 73 in each of two opposite directions. As applied to the control of the cam shaft 22 of a fuel-injection pump 20, the shaft 36 is driven from the engine through a gear 44 and has a bearing 35 in one end of a casing 24. The casing 73 is formed as an enlargement of the end of the shaft 36. Four equispaced sectorshaped abutments 74 are mounted inside the casing 73 by means of bolts 76 and the casing is closed by an end plate 75. The spaces between the abutments 74 are occupied by the vanes 82 which spring from a hub 81 splined in a flanged coupling 87 mounted on the cam shaft 22. The hub 81 is rotatably mounted on a control valve 50 itself rotatable within the driving shaft 31. The valve 50 is rotated relative to the shaft 36 by a centrifugal mechanism comprising fly-weights 54 pivotally mounted on a member fixed to the gear and operative through pins 58 working in cam slots 59 to turn a transverse arm 49 rigid with the valve 50. Hydraulic operating fluid is supplied to a chamber 63 in the valve through passages 68, 37, 64 and a check valve 70. The valve also has an open-ended exhaust chamber 85 communicating through passages 94 in the coupling 87 with the casing 24. The valve 50 has two sets of radial ports 105, 106 opening from the chamber 63 and two sets 107, 108 opening from the chamber 85. Pressure fluid is supplied to the " advance " side of the vanes 82 through ducts 98 and to the "retard" side thereof through ducts 101, these co-operating with the ports 105, 106 respectively. Similarly fluid is exhausted from the "retard" side of vanes through ducts 99 and from the advance " side through ducts 102. The ducts 99, 102 open at their outer ends through ports 100, 103 respectively so that any impurities in the fluid thrown to the outer walls of the vane chambers by centrifugal force are removed by the outflowing fluid. In the full retard position and under steady speed conditions all four sets of ports 105, 106, 107, 108 are lapped. In the fully advanced position, however, the ports 105, 107 are cracked open so that any leakage across the vanes is made good. The vanes 82 engage the abutments 74 in the fully advanced and fully retarded positions and in the latter the vanes are driven mechanically by the abutments. In a modification, Figs. 11 to 15 (not shown), the valve 50 is keyed to rotate with the shaft 36 and is moved axially by the flyweights. In this case the valve has inclined or helical grooves on its outer surface connected to the chambers 63, 85 and co-operating with the ducts 98, 101, 99, 102. In a further modification the fly-weights are dispensed with and the valve 50 is moved axially by a screwed spindle acting through a flanged coupling which permits rotation of the valve by the driving shaft. In a further modification, Figs. 20, 21, 22 (not shown), a flat end surface on a head provided on the valve co-operates with the outer end of the hub 81 in the manner of a rotary disc valve.