| 摘要 |
<p>The hybrid propulsion system is partic. for a vehicle, having a free piston type engine-pump unit connected to a working fluid circuit for controlling pressurisation of a working fluid. The fluid in turn drives a hydraulic motor interconnected to the vehicle wheels. The motor-pump unit includes a free piston assembly having a pair of fixedly connected power pistons, each of which has a pump piston fixed to it. The fluid system includes high and low pressure accumulators in communication with pumping chambers associated with the pump pistons. The power pistons are used for driving the pump pistons to pressurise the working fluid when self-sustained operation of the engine-pump unit is desired. The flow of working fluid to the pumping chambers can be reversed during startup of the engine so that the high pressure fluid is used for driving the free piston assembly until it is reciprocated at a rate rapidly enough to permit self-sustained reciprocation.</p> |
