加拿大的国家研究委员会设计出一种回热动力机车,采用一种水力泵以作为机车常规刹车系统的补充,并能将通常存合闸时损失能量加以存贮和再循环。这种系统包括一台加压氮气汽缸,它由一个狭窄活塞与油箱分隔开。司机合闸时,泵强迫更多的油进入汽缸,因而增加了氮压和主动轴的制动力。司机加速时,氮压缓释,强迫油回入泵中,泵就以一台电机形式转动主动轴。此系统可降低燃耗30％,同时可减少外泄和刹车磨损 Canada’s National Research Council has devised a recuperative power locomotive that uses a hydraulic pump to supplement the conventional braking system of a locomotive and can store and recycle the lost energy that normally would have been parked. This system includes a pressurized nitrogen cylinder, which is separated from the tank by a narrow piston. When the driver closes, the pump forces more oil into the cylinder, thus increasing the nitrogen pressure and braking force of the driveshaft. When the driver is accelerating, the nitrogen pressure is slowly released and the oil is forced back into the pump. The pump rotates the drive shaft in the form of a motor. This system reduces fuel consumption by 30% while reducing leakage and brake wear