Abstract: A method is provided for controlling a normal force in a frictional contact of a continuously variable transmission including an input pulley and an output pulley where between an endless transmission element is arranged that is held between and in frictional contact with two pulley discs of each respective pulley under the influence of a respective normal force, wherein, as part the control method, the normal force at one pulley is actively oscillated, wherein a resulting oscillation of one of, or a ratio or difference between both of, a rotational speed of the input pulley and a rotational speed of the output pulley is determined and wherein at least one normal force is controlled in dependency on a correlation between the active oscillation and the resulting oscillation. The method includes a calibration step wherein a phase difference between the active oscillation and the resulting oscillation is determined.

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: A method is provided for controlling a normal force in a frictional contact of a continuously variable transmission including an input pulley and an output pulley where between an endless transmission element is arranged that is held between and in frictional contact with two pulley discs of each respective pulley under the influence of a respective normal force, wherein, as part the control method, the normal force at one pulley is actively oscillated, wherein a resulting oscillation of one of, or a ratio or difference between both of, a rotational speed of the input pulley and a rotational speed of the output pulley is determined and wherein at least one normal force is controlled in dependency on a correlation between the active oscillation and the resulting oscillation. The method includes a calibration step wherein a phase difference between the active oscillation and the resulting oscillation is determined.

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).