Patent GB-1067838-A (GB)
Title: Improvements in power transmission servo-control systems for motor vehicles
IPC: F16H59/18
Filed: 1964-06-15
Abstract: 1,067,838. Change-speed and clutch control. REGIE NATIONALE DES USINES RENAULT. June 15, 1964 [June 18, 1963], No. 24786/64. Headings F2D and F2L. [Also in Division H2] In a control, in a motor vehicle, for establishing or disestablishing coupling between the engine and the vehicle driving wheels and/or varying the ratio in a change-speed gear, voltage varying as a function of the vehicle or engine speed and of accelerator pedal 32 position is supplied by an alternator comprising an axially fixed permanent magnet rotor 1 coupled to the change-speed gear output or engine shaft, and a stator 11 axially movable by the pedal 32 to vary the rotor magnetic flux to which the stator is subjected. The rotor, which may be of sintered metal grains, is supported on an oil-sealed shaft 2 which is connected to a driving shaft by a dog connection allowing some misalignment and avoiding vibration due to magnetic snatching. A dog 5 having a bore greater than the diameter of the shaft 2 engages a screw-driver shaped driving shaft end, and is drivingly connected to the shaft 2 by a cross-pin.6 which is a tight-fit in the dog and an easy sliding fit in the shaft 2 and is retained by a spring ring 7. The stator comprises intercalated taper pole fingers 14 alternately axially extending from flanges 12, 13. The pole finger extremities penetrate, with clearance, slots (15) in the opposite flanges. The pole finger roots and extremities may have sharp or rounded corners, A winding 25 surrounds the pole fingers. The stator magnetic circuit is closed by a ring 17 which for sliding movement in the bore 10 of a housing 4 is made of oil impregnated sintered iron, is coated externally with a low-friction coefficient material such as P.T.F.E., or accommodates antifriction balls. The stator is restrained circumferentially and its axial movement is limited by a lug 36 engaging an axial groove 35 in the ring 17. The flange 12 is clamped between the ring 17 and an insulating flange 20 through which passes terminals 23, 24 of the winding 25 and which is connected to the accelerator pedal by a pin-and-slot connection 33, 34, an arm 21, a shaft 22 and a linkage typified by an arm 31. The terminals 24, 23 are connected to external terminals 28, 29 by conductive springs 26, 27. The voltage for a given speed is arranged to vary only slightly during the first part of the accelerator pedal movement. In a 3-speed gear control (Fig. 5, not shown), the rotor is connected to the gear-box output shaft and the winding 25 is connected to fixed resistors or, as shown, variable potentiometer tappings (39), (40) respectively connected through threshold, opposed Zener and ordinary, diodes (43), (44), and on/off amplifiers (41), (42) to windings (45), (46) of successively actuated 1-2, 2-3 electromagnetic hydraulic shift valves. Preferably the amplifiers include an electrical hysteresis effect to cut off current to the windings (45), (46) when output shaft speed falls to less than that required for winding energization. To adjust the shift points the accelerator pedal to stator linkage may be modified.