| 摘要 |
A vehicle hydraulic system 10 comprises a first pump 12 driven by a prime mover 16, a second pump 14 driven by a ground engaging member, preferably a wheel 40, and a steering control system 34 having a hydraulic supply input. A distribution circuit 22 connects outputs of the first and second pumps 12,14 to the hydraulic supply input. The second pump 14 is a variable displacement pump having a piston stroke that can be varied to adjust the output flow volume. The piston stroke is controlled in response to the output of the first pump 12. The hydraulic system 10 is operable in an emergency steering mode in which the first pump 12 is isolated from the steering control system 34 by the distribution circuit and the steering control system 34 is supplied with pressurised fluid from the second pump 14. |
