Vehicle propulsion system with inertial storage

Claim 1

A propulsion arrangement for a vehicle, comprising an engine having an output shaft, a first shaft, first means for coupling and de-coupling said output shaft to and from said first shaft, in the coupled condition said shafts rotating at a first fixed speed ratio therebetween, a flywheel, second means for coupling and de-coupling said flywheel to and from said first shaft, in a coupled condition said flywheel and first shaft rotating at a second fixed speed ratio therebetween, a variable transmission means having an input connected to said first shaft, and an output, a vehicle drive shaft connected to the transmission output, driver operable controls, means for sensing rotational speeds of said engine, said flywheel, and said drive shaft, electronic control means responsive to said driver operable controls and speed of said engine, flywheel and the drive shaft for controlling power supplied by the engine and the input/output ratio of the transmission means, and for selectively operating said first and second means for coupling and de-coupling, and means for applying a small coupling torque between said flywheel and said first shaft when said second means is in a de-coupled condition and said first shaft speed is greater than a predetermined value.