Hydraulic drive system has valve assembly for controlling respective fluid flow, which is provided with primary and secondary valve sub-assembly to perform same switching function, in which valve sub-assemblies are connected in series

摘要

The hydraulic drive system (10) has a pump (12), an actuator (13) and a redundant valve assembly (14). The pump is provided for conveying the hydraulic fluid to the actuator. The valve assembly is provided to control the respective fluid flow. The valve assembly is provided with a primary valve sub-assembly (20) and a secondary valve sub-assembly (30) to perform the same switching function. The primary and the secondary valve sub-assemblies are connected in series.