Abstract: A variator transmission comprises an input shaft (18), an input disc (10) mounted on the input shaft for rotation therewith and an output disc (12) facing the input disc and arranged to rotate coaxially therewith, the input and output discs defining between them a toroidal cavity. Two rollers (14, 16) are located in the toroidal cavity and first and second roller carriage means are provided upon which the first and second rollers respectively are rotatably mounted and end load means (34, 36) urge the rollers into contact with the input and output discs to transmit drive. The two roller carriage means are mounted on opposite sides of the pivotal axis of a lever (50) and the pivotal axis of the lever (50) is movable in both the radial and non-radial directions with respect to the rotational axis of the input and output discs.

Abstract: A variator transmission comprises an input shaft (18), an input disc (10) mounted on the input shaft for rotation therewith and an output disc (12) facing the input disc and arranged to rotate coaxially therewith, the input and output discs defining between them a toroidal cavity. Two rollers (14, 16) are located in the toroidal cavity and first and second roller carriage means are provided upon which the first and second rollers respectively are rotatably mounted and end load means (34, 36) urge the rollers into contact with the input and output discs to transmit drive. The two roller carriage means are mounted on opposite sides of the pivotal axis of a lever (50) and the pivotal axis of the lever (50) is movable in both the radial and non-radial directions with respect to the rotational axis of the input and output discs.

Abstract: A variator transmission apparatus (10) comprises an input shaft (12), one or more input discs (14, 16) mounted on the shaft for rotation therewith, one or more inner discs (18, 20), the input and output discs defining between them one or more toroidal cavities, a plurality of rollers (22, 24) located within the one or more cavities for transmitting rotation from the outer disc(s) (14, 16) to the inner disc(s) in which means are provided for preventing the end load locking the inner discs (18, 20) to the shaft (12).

Abstract: A vehicle driveline including a control system subject to operator demand, and a continuously-variable-ratio transmission including a variator of the torque-controlled type in which the control system includes a performance "map" of optimum relationships between engine torque and speed over a range of values of those two quantities, and in which the control system regulates both the energy input to an engine and also the reaction torque at the variator so as to seek a state in which the mapped optimum relationship between engine torque and speed is maintained. The variator may be of the toroidal-race rolling-traction type, reaction torque within it being regulated by controlling the operating force applied to the variator rollers.

Abstract: A roller control system for a continuously-variable-ratio transmission of the toroidal race, rolling traction type, in which rollers (60) of variable orientation transmit traction between a part-toroidal race (85) formed on an input disc (61) and a similar race (87) formed on a coaxial output disc (62). Each roller is mounted to rotate about a fixed centre (66) and a fixed axis (58) within a rigid carriage (67), one end of which contacts operating mechanism reciprocable over a predetermined stroke of operating movement and operable to apply a control force to the carriage. The assembly of roller and carriage is located by only three contacts with adjacent structure, namely the two disc/roller contacts (86, 88) and the contact (82) with the operating mechanism.

Abstract: A ratio-varying component for a continuously-variable-ratio transmission of the toroidal-race rolling-traction type, in which each roller (20) spans the toroidal clearance between its respective input (4, 5) and output (11, 12) discs diametrically and the roller center (20b) is capable in operation of limited movement back and forth along the center circle (22a) of the clearance, and in which stop means (40, 41; 30, 33) are mounted adjacent both the outer and inner edges of the part-toroidal races (22, 23) on the discs, to prevent the rollers from running off the edges.

Abstract: A variator for a transmission of the toroidal-race rolling-traction type in which a multiplicity of input discs (1-4) and output discs (11-13) are arranged in coaxial sequence, all disc except the first (1) and last (4) in the sequence being formed with races (9, 10) on both of their faces. Drive is transmitted from the output discs to one (35) or several (45-47) output shafts, the output shaft or shafts preferably lying parallel to but displaced from the common axis (8) of the discs. Alternative ways of inter-relating the orientation of the torque-transmitting rollers (20), to produce single or multiple outputs of the transmission, are described. The invention offers the prospect of a variator of higher-than-normal traction-transmitting capacity but using discs of only normal size.

Abstract: A continuously-variable ratio transmission of the toroidal-race rolling-traction type, especially in and for an automobile vehicle. The ratio transmitted by the rollers (10) is determined by the position of a double-ended piston (15), the ends of which move in cylinders (17, 16) respectively connected to further cylinders (31, 36) the pistons (33, 38) of which are movable by the opposite limbs of a rocking pedal (42) controlled by the operator. Rocking of the pedal in one direction depresses one such piston (e.g. 33) and releases the other, thereby moving the double-ended piston (15) in one direction and so inducing ratio change in one sense, while rocking the pedal in the opposite direction has the opposite effect. The cylinders (31, 36) of the pedal-controlled pistons may be mounted in a fluid reservoir (34), and formed with ports through which the fluid lines are topped-up from the reservoir each time the pistons (33, 38) rise close to the tops of their strokes.

Abstract: A hydraulic control valve for a continuously-variable-ratio transmission (CVT), particularly one of the toroidal race rolling traction type. The transmission includes hydraulically-operated clutches (25,26) whose capacity to transmit torque varies with the operating pressure supplied to them. The transmitted ratio is related to the position of a hydraulic ram (35), which when it overshoots its normal stroke creates a pressure rise upstream of it in the circuit. This pressure rise first resists further overshoot, and then causes a reduction in the clutch operating pressure. Ram position is controlled by valves (56,57) which are located downstream of the ram, and which are themselves sensitive (via 58) to feedback from upstream circuit pressure: when that pressure rises, the valves open so as to depress the downstream circuit pressure by which the clutches are operated (via 68).

Abstract: A two-regime CVT for a tracked vehicle steered by differential movement of its tracks, comprising two ratio-varying units of the toroidal-race, rolling-traction type, which drive the vehicle without steer when their outputs are the same, but with steer when those outputs differ. Each such output is connected respectively by way of a steering epicyclic gear set to the drive of one of the tracks. According to one aspect of the invention the axes of the two variators and of the inputs from them to the two steering epicyclics are all coaxial, and may also be coaxial with the input to a third epicyclic gear set operable to change the transmission between its two regimes.

Abstract: A driveline for a track-laying vehicle having a prime mover and a pair of output shafts (L, R) connected to drive left- and right-hand tracks comprises: two similar continuously-variable-ratio transmissions (10, 20) of the toroidal race-rolling traction type, each having an input adapted to receive input drive from the prime mover and an output; a cross shaft (CS); two similar summing epicyclic gear output units (12, 22) each having a first input (70, 80) geared to the output of a respective transmission unit, an output connected to a respective output shaft (73, 83), and a second input (72, 82) connected to the cross shaft; gear drain (30) for connecting the input drive to the cross shaft at a first predetermined ratio, for low regime operation; a middle regime differential gear arrangement (40) having two inputs connectable at second and third predetermined gear ratios respectively to the corresponding first inputs of the output epicyclic gear units, and an output connectable at a fourth predetermined gear

Abstract: A diesel engine (1) drives an axle (4) through a continuously-variable-ratio transmission (3), e.g. of the toroidal race rolling friction type. A flywheel system (5) is coupled to the input of the transmission (3) by reduction gearing (8, 9). Sprag clutches (2, 6) ensure that the transmission selects whichever is the faster of the engine or the flywheel, and a multiplate clutch (7) parallel with the flywheel sprag clutch (6) is engaged for regenerative braking. Parasitic losses during flywheel drive are reduced by operating the flywheel in a referred speed range coinciding with the engine speed range.

Abstract: In a continuously-variable-ratio transmission of the toroidal race rolling traction type, each roller is mounted between the opposing disc surfaces in a roller mounting which is displaceable by an hydraulic ram. Each end of the ram has a piston (13 or 14) at the end of the roller mounting sliding in a cylinder (15 or 16).The hydraulic control system has a combined flow divider and pressure control valve (23) which responds to external control forces (C1 or C2) from solenoids to shift the roller mounting.Fluid flow in both hydraulic circuits (P, JJ', L'L, R, T and S, MM', K'K, Q, T) is always equalized by the valve (23). Thus displacement of the spools (S1, S2) away from equilibrium, by restricting inlet and outlet ports (R and S or P and Q), raises the pressure in one ram chamber (16 or 15) and displaces the ram. Moreover, the same pressure tends to return the spools to the equilibrium position.

Abstract: A driveline for an engined vehicle, comprises a continuously-variable ratio transmission (1) having an input adapted to be driven by the engine and an output (3), a final drive shaft (8) for providing an output from the driveline, and means for driving the final drive shaft from the continuously-variable ratio transmission in either high or low regime. In low regime the final drive shaft is driven by the output (7) of an epicyclic (4) having first and second inputs (6,5) connected to be driven respectively by the said engine and by the said continuously-variable ratio transmission output and in high regime the final drive shaft is driven directly by the output (3) of the continuously-variable ratio transmission.

Abstract: A driveline for a track-laying vehicle such as a tank includes a propulsion transmission (200) and a steer transmission (100), both driven from the engine crankshaft (1), and both of the toroidal race-rolling traction type continuously-variable ratio transmissions. An arrangement of epicyclic gears (12, 13) and clutches (H, C1, C2) transmits drive from the propulsion variator (200) in four regimes to summing epicyclic gears (6, 7) associated with left-hand and right-hand tracks. Steering of the tracks is achieved by summing the drive, in the summing epicyclic gears (6, 7), from the steer variator (100).

Abstract: Two piston and cylinders 13, 15 and 16, 18 control the force reaction of a roller mounting in a continuously-variable-ratio transmission of the rolling traction type. A pressure control valve 23 controls the net force on the roller mounting by controlling the relative pressure in two pressure lines which include the cylinders. A flow dividing valve 22 equalizes the flows in the lines by feedback across two identical orifices 26, 27. Excessive displacements of the roller mounting (which could cause the rollers to run off their toroidal races) are controlled by ports 19, 20, which are restricted at respective ends of the permissible movement. The restriction causes a pressure build up in the cylinder which resists that threatening the original overshoot, while restricting the effect of the pressure control valve by virtue of the action of the orifices 26, 27 and flow dividing valve 22, and this also reduces the pressure which originally threatened the overshoot.

Abstract: A diesel engine 1 drives a continuously-variable-ratio transmission 3 via an over-running clutch 2 and the transmission in turn drives a drive axle 4. A flywheel 5, used to store energy when the vehicle equipped with the driveline is braked, is energized via the transmission and also drives it when returning its stored energy to the vehicle.The connection between the flywheel 5 and the transmission 3 is via an over-running clutch 6 and a centrifugal clutch 7. The centrifugal clutch closes at a speed which is such that the speed of the gear 9 is a little above the maximum speed it could be driven by the engine 1. When the flywheel 5 is not energized, the centrifugal clutch 7 is open and the engine 1 drives the transmission 3 via the clutch 2 and, after bringing the flywheel up to a speed corresponding to maximum engine speed, the flywheel is not driven so long as the engine speed is below maximum (because of clutch 6).