GB691884A - Improvements in and relating to electric propulsion and steering systems - Google Patents

Abstract

691,884. Transmitting mechanical power. BRITISH THOMSON-HOUSTON CO., Ltd. March 13, 1951 [March 31, 1950], No. 6041/51.. Class 38 (iv). [Also in Group XXXVII] A self-propelled vehicle, such as a tractor, is driven by an internal-combustion engine 10 through an electrical transmission comprising a generator 11 coupled to the engine and electric driving motors 14, 15 supplied by the generator and coupled, respectively, to road wheels, or tracks, on opposite sides of the vehicle. The fields 16, 17 of the motors are individually excited by amplidyne machines 18, 19 driven by the engine and having control fields 21-24 excited from sources 29, 43 over potentiometers 27, 28, 41, 42 actuated by a joy-stick 30, the arrangement being such that forward or reverse movement of the vehicle, or its turning to the right or left, results from a corresponding movement of the joy-stick from its neutral position. To this end, the potentiometers 41, 42 (controlling the " forward-reverse " fields 22, 24 of the amplidynes) are connected reversely across source 43, whilst the potentiometers 27, 28 for the " steering " fields 21, 23 are reversely connected across, source 29. A bridge circuit 25, 26, 35, 37 applies negative feed-back in the " steering" field circuit. The generator may be excited by an amplidyne machine having a control winding responsive to generator current and another winding, controlled through a relay and motor-driven tachometer generator, for providing speed-limiting control for the field of the generator exciter. A further field may be excited in accordance with movement of the engine throttle. The joy-stick controller may comprise a rod 30a, Fig. 3, having a forked end 46 which engages a U-shaped bracket 48 pivoted in uprights 49, 50 and attached to a shaft 52 which operates one pair of potentiometers. The forked end 46 is attached to, a ring 47 pivoted to a U-bracket 54 which is secured to a further U-member 55 pivoted between uprights 56, one of the pivots being extended to form an operating shaft 58 for the other pair of potentiometers. Specification 539,835 is referred to.