| 摘要 |
A steering arrangement (20) including a first hydraulic pressure chamber (31), a second hydraulic pressure chamber (32), a third hydraulic pressure chamber (33) and a fourth hydraulic pressure chamber (34), the first and third pressure chambers (31, 33) being selectively operable to steer in a first direction and the second and fourth pressure chambers (32, 34) being selectively operable to steer in a second direction,
a pump system (22) for supplying pressurised fluid to a steering system (24),
the steering system (24) being operable to supply the pressurised fluid to one or more of the first, second, third and fourth hydraulic pressure chambers (31, 32, 33, 34),
the steering system (24) having a first mode wherein pressurised fluid is simultaneously supplied to the first and third hydraulic pressure chambers (31, 33) to steer in the first direction or wherein pressurised fluid is simultaneously supplied to the second and fourth hydraulic pressure chambers (32, 34) to steer in the second direction,
the steering system having a second mode wherein pressurised fluid is supplied to one of the first and third hydraulic pressure chambers (31, 33) to steer in the first direction or wherein pressurised fluid is supplied to one of the second and fourth hydraulic pressure chambers (32, 34) to steer in the second direction,
such that the steering ratio is higher in the second mode than in the first mode. |
