| 摘要 |
A chuck actuator has a cylinder extending along an axis and having an axially extending stem whose outer surface is formed with a pair of central radially outwardly open and axially spaced intake ports, a piston axially displaceable in the cylinder and forming therein two compartments connected via respective passages connected to the intake ports, two axially spaced bearings on the stem, and a connector supported by the bearings on the stem. This connector normally is restrained against rotation relative to the axis and has an inner surface closely juxtaposed with and forming with the stem surface an interface. Respective radially inwardly open and axially spaced inner feed grooves open at the interface level with the respective intake ports. Two independent hydraulic fittings communicating with the inner feed grooves can pass pressurized liquid to the respective compartments. A pair of middle lubricating grooves immediately axially flanking the inner feed grooves and opening radially inward at the interface, are connected to a drain chamber below the axis by respective middle drain passages extending downward from the middle lubricating grooves to the drain chamber. A shunt passage carries liquid axially therebetween and respective lubricating passages carry liquid from the middle grooves to the bearings. Respective outer drain grooves open radially on the connector between each bearing and the respective middle groove, and are connected with the bearings by respective outer drain passages to the drain chamber. |
