| 摘要 |
PCT No. PCT/DE97/00024 Sec. 371 Date Oct. 6, 1997 Sec. 102(e) Date Oct. 6, 1997 PCT Filed Jan. 9, 1997 PCT Pub. No. WO97/34094 PCT Pub. Date Sep. 18, 1997A hydraulic emergency control for a gear-ratio-dependent change in hydraulic fluid pressures in a first and second hydraulic bevel-gear axial adjuster of a continuously variable transmission (10), is provided in which a pump (1) supplies at least the piston chamber (17) of the second axial adjuster, and at least one downstream pressure limiting valve (40) limits the fluid pressure there and moreover from this supply, via a continuous path valve (20), supplies the piston chamber (13) of the first axial adjuster, and the continuous path valve (20) is controlled with the aid of a pressure differential acting on a throttle valve (39) that is downstream of the pump (1) and is integrated with a switching valve (30). The switching valve (30', 30'', 30'''), the continuous path valve (20', 20''), and the pressure limiting valve (40', 40'', 40''') are each hydraulically triggered via at least one of a plurality of pilot control valves (120, 120'), (140, 140'), (160, 160') and (170, 170') counter to the action of a mechanical or hydraulic actuator disposed on the corresponding controlled valve. With the aid of the pilot control valves, among other things the switching valve is hydraulically controlled in such a way that it detects the control failure from control pressure changes in the system and switches over to an emergency operation mode.
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