A clamping device for expanding a threaded bolt is provided with a support pipe supported against an underlay surrounding the threaded bolt. A cylindrical housing arranged in extension of the support pipe has a piston movable in longitudinal direction and connectable to a hydraulic supply. A changeable bushing is axially carried by the piston and is provided with an inner thread and a radially expanded portion. A resilient arrangement is arranged around the bushing and acts axially on the piston. A lid is secured to the housing. The other support of the resilient arrangement is provided on the lower side of the housing. The lid has a lid base member and a closure lid. The lid base member is provided with an opening closable by the closure lid. The radial extent of the opening is greater than the radial extent of the radially expanded portion of the bushing.

A hydraulic tensioner (1), comprising: abase (2); a piston (3) mounted for sliding motion relative to the base (2), the base (2) and the piston (3) defining a pressure space (4) therebetween and being arranged to be urged apart along an axis (8) upon introduction of a fluid into the pressure space (4), the tensioner (1) having an internal bore (6) along the axis (8) having first and second ends along the axis and comprising a threaded component having an internally threaded portion (7) at the first end and coupled to the piston (3); the tensioner (1) further comprising: a threaded stud (10) having an exterior thread which engages the internally threaded portion (7) of the threaded component; and a drive mechanism (12) arranged to transmit rotational motion from the second end of the internal bore (9) to the threaded stud; the tensioner being arranged such that rotational motion applied to the drive mechanism (12) at the second end causes rotation of the stud (10) relative to the threaded component, with the engagement of the exterior thread of the stud (10) and the internal thread of the threaded component causing the stud to move along the axis as it rotates.

A hydraulic tensioning apparatus for tensioning a threaded member (2) having a thread, comprising: a hydraulic tensioner (1), having a body (4) and a pressure space (13) for hydraulic fluid and having a thread engaging member (7) arranged to engage the thread of the threaded member (2) and to be urged away from the body (4) on introduction of hydraulic fluid into the pressure space (13) so as to tension the threaded member (2); a displacement sensor (11, 12) arranged to measure a linear displacement of the thread engaging member (7) relative to the base (4) and to provide an output indicative of the linear displacement; a rotation sensor (65, 66) arranged to determine a rotation of a nut (3) rotating on the threaded member (2) and arranged to produce output indicative of a rotation angle of the nut (3); and a control unit (80) arranged to take as inputs the outputs of the displacement sensor (11, 12) and the rotation sensor (65, 66), and to determine from the output of the displacement sensor (11, 12) a required angle of rotation of the nut (3) which accommodates for extension of the threaded member (2) due to being tensioned by the hydraulic tensioner (1).

A tightening device for a wind turbine configured to fasten and/or tighten a plurality of fastening means to a fastening target object, wherein the fastening means are arranged in a fastening means circle is provided. The tightening device includes a center bearing unit for allowing the rotation of the tightening device about a center axis, a torque unit for applying torque on the fastening means to fasten and/or tighten the fastening means to the fastening target object, and a first arm extending in a radial direction from the center bearing unit and supporting the torque unit.

System for supplying hydraulic pressure to a bolt elongation tool, comprising the bolt elongation tool with at least one pressure chamber and a tool piston, a hydraulic medium supply system and a hydraulic actuator with an actuator cylinder housing an actuator piston. The actuator cylinder is attached to the at least one pressure chamber, wherein the hydraulic actuator is an electro-hydraulic actuator comprising an electric motor built to generate the power of the electro-hydraulic actuator, and wherein the actuator piston is built to supply, with one stroke of an actuator stroke height of the actuator piston, at least the amount of hydraulic pressure that is needed to move the tool piston for the amount of one tool stroke height of the tool piston.

A method for erecting a wind turbine tower is disclosed. A tower section (8) comprising a lower flange (9) and an upper flange (10), and a plurality of stud bolts (6) and nuts (7) are provided. The tower section (8) is oriented in an upright position with the lower flange (9) below the upper flange (10), and stud bolts (6) are positioned in bolt holes (12) in the lower flange (9) with nuts (7) arranged on an upper side of the lower flange (9). The tower section (8) is lifted to a mounting position on top of another tower section (13), and a flange combination is formed by aligning the bolt holes (12) formed in the lower flange (9) of the tower section (8) with bolt holes (15) formed in an upper flange (14) of the other tower section (13), while advancing the stud bolts (6) through the bolt holes (12, 15). The invention further provides a socket tool (16) for screwing nuts (7) onto stud bolts (6) in a manner which positions the stud bolts (6) correctly with respect to a flange (9).

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 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.

In a fastening device for fastening a bolt, a male thread is formed on a side surface of a bolt head part, and a part to be engaged is formed on a top surface of the bolt head part. The fastening device includes a bit having a tension rod having a rod female thread part, and an engaging part installed inside the tension rod and engaging the engaged part, the bit causing the bolt to rotate where the engaged part and engaging part are engaged; a supporter surrounding the tension rod in the circumferential direction such that the lower end part thereof protrudes below the lower end part; a sensor for sensing vertical compression force acting on the supporter; a first motor for causing the bit to rotate about the axis; and a second motor for causing the tension rod to rotate about the vertically extending axis.