Stufenlos verstellbares Getriebe und Steuerungsverfahren dafür

摘要

The invention relates to a continue variable transmission comprising a pair of pulleys forming V-shaped grooves for receiving an endless transmission element for transmitting torque between the pulleys, each pulley comprising at least one axially movable sheave which may be urged axially in the direction of the transmission element by an urging means effecting a clamping force between said sheave and said transmission means, the effected clamping force corresponding to a force sufficient for transmitting a torque to be transmitted by at least virtually slipless friction between the pulley sheaves and the belt, increased by a safety margin the safety margin is being a factor corresponding to a percentage of the torque to be transmitted throughout a major part of the range of torques transmittable to the relevant transmission, wherein in that the safety factor is set as a function of the torque to be transmitted and the actual transmission ratio, such that the actual safety factor at predefined transmission modes is reduced to a lower value at increased levels of actual torques to be transmitted and with increased actual transmission ratio values.