摘要:
Three clutch system for operating the composite transmission power train of a farm tractor, comprising first and second power shift clutches, and a master clutch connected by intervening gearing in separate paths to the different power shift clutches so as to be in series with either one. The power shift clutches are selectively connected by electrical hydraulic controlling means to a tractor engine at an engine connected end of a speed transmission in the power train; the master clutch is at the output end of the speed transmission, connecting it to a range transmission which completes the composite transmission power train hereof. A digital microcomputer chip is responsive to manually controlled engagement and disengagement of the master clutch and to other critical control parameters, and is programmed to monitor and control the three clutch controlling means.