Abstract: A continuously variable transmission is provided with a drive belt (6) drive belt (3), fitted between a primary pulley (1) and a secondary pulley (2) of the transmission, each pulley having two pulley sheaves (4, 5) of which at least one pulley sheave (4) in each case is axially movable under the influence of a hydraulic pressure exerted in a pressure cylinder (11; 12) of a respective pulley (1; 2), and with a hydraulic control system for controlling these respective cylinder pressures (Pp, Ps) including two oil pumps (41, 42). A pump flow control valve (100, 48) is provided and is arranged to connect to or disconnect from the main hydraulic line (46) the one oil pump (42) in dependency on a difference between an actual line pressure (Ps) in the main hydraulic line (46) and a desired pressure level there for.

Abstract: A hydraulic control system in a continuously variable transmission (2) is provided with a pump (40) for supplying hydraulic fluid, a main line (41), a line pressure valve (V3), an auxiliary line (42) and a auxiliary pressure valve (V9). The line pressure valve (V3) being arranged to control a line pressure LP in the main line (41) by discharging a surplus of hydraulic fluid supplied by the pump (40) into the auxiliary line (42). The auxiliary pressure valve (V9) is arranged to variably control auxiliary pressure AP in the auxiliary line (41), preferably in dependence on the line pressure LP in the main line (41).

Abstract: A continuously variable transmission is provided with a drive belt (6) drive belt (3), fitted between a primary pulley (1) and a secondary pulley (2) of the transmission, each pulley having two pulley sheaves (4, 5) of which at least one pulley sheave (4) in each case is axially movable under the influence of a hydraulic pressure exerted in a pressure cylinder (11; 12) of a respective pulley (1; 2), and with a hydraulic control system for controlling these respective cylinder pressures (Pp, Ps) including two oil pumps (41, 42). A pump flow control valve (100, 48) is provided and is arranged to connect to or disconnect from the main hydraulic line (46) the one oil pump (42) in dependency on a difference between an actual line pressure (Ps) in the main hydraulic line (46) and a desired pressure level there for.

Abstract: A hydraulic control system in a continuously variable transmission (2) is provided with a pump (40) for supplying hydraulic fluid, a main line (41), a line pressure valve (V3), an auxiliary line (42) and a auxiliary pressure valve (V9). The line pressure valve (V3) being arranged to control a line pressure LP in the main line (41) by discharging a surplus of hydraulic fluid supplied by the pump (40) into the auxiliary line (42). The auxiliary pressure valve (V9) is arranged to variably control auxiliary pressure AP in the auxiliary line (41), preferably in dependence on the line pressure LP in the main line (41).

Abstract: The invention provides for a vehicle drive line provided with an engine (1) capable of generating an engine torque (Te), a continuously variable transmission (2), a driven wheel (5) and two friction clutches (3, 33), a first clutch (3) being positioned in the drive line between the engine (1) and the transmission (2) and a second clutch (33) being positioned between the transmission (2) and the driven wheel (5), wherein a torque (Tc-max) that is transmissible by the first clutch (3) and a torque (Tc-max) that is transmissible by the second clutch (33) are both less than a torque (Tt-max) transmissible by the transmission (2) and, at the same time, are both essentially equal to or slightly higher than the engine torque (Te).

Abstract: The invention provides for a vehicle drive line provided with an engine (1) capable of generating an engine torque (Te), a continuously variable transmission (2), a driven wheel (5) and two friction clutches (3, 33), a first clutch (3) being positioned in the drive line between the engine (1) and the transmission (2) and a second clutch (33) being positioned between the transmission (2) and the driven wheel (5), wherein a torque (Ta-max) that is transmissible by the first clutch (3) and a torque (Tc-max) that is transmissible by the second clutch (33) are both less than a torque (Tt-max) transmissible by the transmission (2) and, at the same time, are both essentially equal to or slightly higher than the engine torque (Te).

Abstract: A hydraulic controller (10, 10a, 10b) for a continuously variable transmission (12) is proposed. Using a pump (42), the delivery chambers (24, 26) of a first and second adjusting device (14, 16) are acted upon to alter the transmission ratio of the transmission (12). The valve (36, 36a, 36b), which can be controlled using a pressure drop created at a throttle position (50), serves to control the pressure in the delivery chamber (24). According to the invention, additional means are provided to prevent an adjustment of the transmission (12) in the “low” direction in the (N) operating state and, as necessary, in the (P) and (N) operating states.

Abstract: A hydraulic controller (10, 10a, 10b) comprising a power part that is supplied by a high-pressure pump (42), and a control part and connecting lines is proposed. According to the invention, a low-pressure pump (64) is provided for the control part. This has an advantageous effect on leakage and fuel consumption.

Abstract: Continuously variable transmission provided with a first pulley having two pulley discs, with a second pulley having two pulley discs and with a drive belt wound around the pulleys for transmitting torque therebetween, at least one disc of the first pulley being axially movable with respect to the other disc of the pulley under the influence of an axial force provided on the movable disc by a hydraulic pressure in a cylinder of a piston/cylinder assembly associated with the first pulley. The continuously variable transmission is further provided with a control system capable of controlling the pressure in the cylinder and including a pump for generating a flow of hydraulic medium from a reservoir to a main hydraulic line and a line pressure valve at least operable by a control pressure which is regulated by an electronically operable pressure regulator, for controlling a line pressure in the main hydraulic line.

Abstract: The invention relates to a continuously variable transmission. The continuously variable transmission according to the invention is designed such that in operating conditions to be defined in more detail the transmission ratio is kept essentially constant, in particular for travelling through bends, on inclines, in case of an emergency stop and during a transmission overspeeding. The constant transmission ratio is obtained while the input r.p.m. of the transmission is changing.