Patent ID: 7686735

Claim:
A continuously variable power-branched transmission for a motor vehicle, said transmission comprising: an input shaft drivable by an engine to provide an input torque; a variable speed drive unit operatively connected with the input shaft and having a continuously variable transmission ratio and including two pairs of axially opposed conical disks wherein a spacing between the disks of a disk pair is axially adjustable; a gear train operatively coupled with the variable speed drive unit and including an output shaft; at least two control clutches for connecting shafts of the variable speed drive unit with the gear train so that when going through the entire transmission ratio range of the power-branched transmission an adjustment range of the variable speed drive unit is passed through a plurality of times; axial force producing means for producing an axial force to reposition one conical disk of a conical disk pair of the variable speed drive unit to adjust the transmission ratio of the variable speed drive unit; means for detecting a change in rotational speed of respective shafts; and a controller operatively connected with the transmission and adapted to make a differentiation as to whether a change in rotational speeds of the shafts is triggered by a change in the transmission ratio, and when the rotational speed change is not triggered by the change in the transmission ratio, to change an axial force imposed by the axial force producing means to compensate for the change in rotational speed that is not triggered by a change in the transmission ratio.