PROCESS FOR OPERATING A VARIABLE DRIVE UNIT

摘要

PCT No. PCT/EP89/00956 Sec. 371 Date Feb. 12, 1991 Sec. 102(e) Date Feb. 12, 1991 PCT Filed Aug. 12, 1989.Arrangement and method of operating a variable drive unit with a selector switch for the preselection of a long-term speed and a control unit which allows for the continuous operation of a continuously variable power split transmission only at reduction ratios ( phi continuous) having a certain minimum interval ( phi min) from the reduction ratio at the shift points between the speed ranges in the mechanical branch of the transmission and the control unit changes the speed of the internal combustion engine in order to reach speeds lying within the minimum interval and controlled by changing the engine speed while maintaining reduction ratio of the transmission instant.