GB423187A - Improved variable speed gear - Google Patents

Abstract

423,187. Hydro-mechanical variablespeed gearing. STOCK, R. T., 23, Mount Road, Hendon, London. July 27, 1933, No. 21148. [Class 80 (ii)] In variable-speed gearing of the kind comprising a transmission epicyclic gear train having a reaction member controlled by an hydraulic coupling, the two elements of the coupling are geared together in a ratio which is fixed or fixable at nearly unity. Planet gears 8, Fig. 1, on a spider 7 fast on a driving-shaft 3 mesh with a sun gear 9 fast on a driven shaft 5 and with an internal gear 10 which is the reaction member. The gear 10 is rigid with the primary element 11 of the hydraulic coupling which is geared to the secondary element 17 in a ratio approximating unity. The hydraulic elements 11, 17 are rigid with internal gears 12, 16, respectively, which mesh with stepped planet gears 13 supported on a loose ring 14, the gears 13 being constrained by being in mesh with a sun gear 13b fixed to the gear casing 1. In a convenient form, the element 17 rotates three per cent slower than the element 11. Vortex motion is set up between the coupling elements, and the torque transmitted may be varied by obstructing vanes 20 arranged round the coupling and movable into the space between the elements 11, 17 either by hand or by a governor. Regulation may alternatively be effected by adjustable sluices or by varying the amount of liquid in the coupling or the distance between the coupling elements. Specifications 1163 /77, [Class 80], and 13864 /06, [Class 69], are referred to in connection with the type of coupling which may be used. In Fig. 3 is shown an arrangement with two transmitting trains for driving forwardly and reversely respectively, and in which speed variation is effected by allowing the constraining or fulcrum sun gears 13b, 35 to slip. The forward train is the same as shown in Fig. 1 except that the sun gear 13b instead of being fixed is connected to an eccentric 25<a> adapted to be held fast or to be allowed to slip away in a controlled manner by an oil pump 37<a> controlled by a throttle valve 42. Rigid with the driving spider 7 is the annulus 26 of the reversing train, the sun gear 29 of which is fast on the driven shaft 5. The reaction member of this second transmission train is the planet-carrier 28<a> which is rigid with a primary hydraulic element 28. The secondary element 30 of this reversing unit is geared to the element 28 by stepped planets 32 on a loose carrier 34 and meshing with a sun gear 35 which is connected to an eccentric 36<a> which can be held fast or allowed to slip away by a second oil pump 38 controlled by a throttle valve 45. Variable forward speeds are effected by closing the valve 42 with the valve 45 open. Variable speeds in the opposite direction are effected by closing the valve 45 with the valve 42 open.