STEUERSYSTEM FUER EIN STUFENLOSES GETRIEBE.

摘要

A control system for an infinitely variable transmission has a transmission ratio control valve having a spool for controlling oil supplied to a cylinder of a drive pulley to change the transmission ratio. The transmission ratio control valve has chambers at both ends of the spool. By controlling the pressure of oil supplied to the chambers in accordance with the difference between a desired transmission ratio and the actual transmission ratio, the spool is shifted, so that the speed of changing the transmission ratio is controlled.