A sealing device for a hydraulic assembly wherein hydraulic fluid is contained in working chamber (53) formed between body (52) and thrust member (51) of the assembly. The device comprises annular seal (63) with opposed sealing faces which are urged into sealing engagement between body (52) and thrust member (51) which have convergent sealing faces. The device may also have a pressure relief valve (100) tapped into the over-stroke end of chamber (53) to protect seal (63) from over-stroke damage comprising porous body (101) which allows fluid to bleed from chamber (53) and allows seal (63) to pass the tapping point without obstruction.

The present invention refers to a device for tensioning a connecting element fastened to a component be tightened, comprising a fixation element for holding the connecting element; a support element for supporting the device against the component; and an actuating unit with a fluid chamber for receiving a fluid and a piston which is translationally guided in the fixation element. The actuating unit is configured for manipulating a volume of the fluid chamber by translationally actuating the piston so as to move the fixation element relative to the support element. The piston is coupled to the fixation element by means of at least one ball or roller screw.

The present invention refers to a device for tensioning a connecting element fastened to a component be tightened, comprising a fixation element for holding the connecting element; a support element for supporting the device against the component; and an actuating unit with a fluid chamber for receiving a fluid and a piston which is translationally guided in the fixation element. The actuating unit is configured for manipulating a volume of the fluid chamber by translationally actuating the piston so as to move the fixation element relative to the support element. The piston is coupled to the fixation element by means of at least one ball or roller screw.

The invention relates to a removable mechanical tensioning system, tool, and a method of stretching a bolt or stud axially, the bolt being located in and attachable to an object via a nut. The system in accordance with the invention comprises an anti-rotation member; and a tensioner device. The anti-rotation member is attachable to both the tensioner device and bolt. The tensioner device is operatively attachable to the bolt via the anti-rotation member. The tensioner device comprises or is operatively coupled to a nut engaging assembly configured to automatically engage and tighten the nut, at a lower torque than the applied tool torque. Displacement of a part of the tensioner device with a holding force applied to the anti-rotation member causes axial stretch of the elongate member and actuation of the nut engaging assembly to bring about displacement of the nut in the transverse direction relative to the stretched elongate member.

The invention relates to a removable mechanical tensioning system, tool, and a method of stretching a bolt or stud axially, the bolt being located in and attachable to an object via a nut. The system in accordance with the invention comprises an anti-rotation member; and a tensioner device. The anti-rotation member is attachable to both the tensioner device and bolt. The tensioner device is operatively attachable to the bolt via the anti-rotation member. The tensioner device comprises or is operatively coupled to a nut engaging assembly configured to automatically engage and tighten the nut, at a lower torque than the applied tool torque. Displacement of a part of the tensioner device with a holding force applied to the anti-rotation member causes axial stretch of the elongate member and actuation of the nut engaging assembly to bring about displacement of the nut in the transverse direction relative to the stretched elongate member.

A screw tensioning device for tensioning or loosing tensionable screw connections comprises a fixation element to be connected to a screw, a support element moveable relative to the fixation element. The support element is arranged moveable relative to the fixation element to apply tension to or remove tension from the screw. A piston is positioned and movable within the fixation element. A volume containing a hydraulic fluid is defined at least partly by the piston, the fixation element or the support element. The movement of the piston manipulates the volume and thereby moves the fixation element with respect to the support element.

A screw tensioning device for tensioning or loosing tensionable screw connections comprises a fixation element to be connected to a screw, a support element moveable relative to the fixation element. The support element is arranged moveable relative to the fixation element to apply tension to or remove tension from the screw. A piston is positioned and movable within the fixation element. A volume containing a hydraulic fluid is defined at least partly by the piston, the fixation element or the support element. The movement of the piston manipulates the volume and thereby moves the fixation element with respect to the support element.

A hydraulic tensioning and release tool for an expansion fastener of a type having an elongate member with a tapered portion for fastening a workpiece. The tool includes a sleeve for placement about the tapered portion; a cylinder(s) including a cylinder for generating compressive force against the workpiece; a release piston for displacing the sleeve and a tension piston for coupling to elongate member. The tension piston and the cylinder(s) defining a tension chamber and the release piston. One of cylinder(s) defines at least one release chamber. Hydraulic ports are in fluid communication with the tension chamber and the release chamber for application of hydraulic pressure to displace the tension piston and the release piston for respectively tensioning the elongate member and for releasing the sleeve from the tapered portion. A tension retaining arrangement retains the elongate member in tension subsequent to removal of hydraulic pressure from the tensioning chamber.

A hydraulic tensioning and release tool for an expansion fastener of a type having an elongate member with a tapered portion for fastening a workpiece. The tool includes a sleeve for placement about the tapered portion; a cylinder(s) including a cylinder for generating compressive force against the workpiece; a release piston for displacing the sleeve and a tension piston for coupling to elongate member. The tension piston and the cylinder(s) defining a tension chamber and the release piston. One of cylinder(s) defines at least one release chamber. Hydraulic ports are in fluid communication with the tension chamber and the release chamber for application of hydraulic pressure to displace the tension piston and the release piston for respectively tensioning the elongate member and for releasing the sleeve from the tapered portion. A tension retaining arrangement retains the elongate member in tension subsequent to removal of hydraulic pressure from the tensioning chamber.

A fully-functional automated bolt tensioning device capable of repeatedly tightening bolts within various locations of an operational wind turbine (e.g., hub, tower, etc.) to a specified tension range is provided. The device includes obstacle detection, alignment, an operational graphical user interface, and nut rotation data acquisition for reduced turbine preventative maintenance cost.