Hydraulic clamping nut with retraction feature - has primary and secondary hydraulic systems for retracting main piston into nut

摘要

The hydraulic clamping element with internal primary hydraulic pressurisation system exerts high pressure for pushing out a piston. A second hydraulic pressurisation system is used for retracting the circular piston and also for reducing the pressure in the primary system. Both pressurisation systems can be remotely controlled by a common actuator for synchronisation to preventing faults which could readily occur due to an automatic synchronisation system. The secondary hydraulic system is associated with the cylindrical bore with an auxiliary piston. This piston has a central bore connected by a hexagon nut and rod to the pressurisation piston. This piston is retracted into the nut body when pressure in the secondary hydraulic piston is increased. The secondary hydraulic systems has a cylindrical annular space with two circular seals.