The invention relates to a method for the controlled and automatic tensioning of bolts pre-installed in a flange joint between a hub and a main shaft in a nacelle of a wind turbine as well as to a bolt tensioning system for such method. The method comprises arranging a fixture inside the nacelle and mounting a bolt tensioning tool to the fixture which is mounted movable in an axial direction and in a working area perpendicularly hereto. First the flange joint is rotated to position a first set of bolts within the working area of the bolt tensioning tool, and then the bolt tensioning tool is controlled alternately to move the tensioning tool into a position for tensioning a bolt and to tension the bolt, until all bolts of the first set of bolts have been tensioned. The rotation of the flange joint may be controlled by operating a rotation tool operably connected to the main shaft, gearbox, and/or generator.

Provided is an apparatus for providing a secure tension connection, the apparatus including a fastener) with a flange for interaction with a shank, a plurality of lifting elements, and a plurality of spacers. Also provide is a wind turbine with such an apparatus, a tool for securing an apparatus and a method for providing a secure tension connection.

In a lifting and transporting device for lifting a load (13) and for transporting the same transversely to the lifting direction (8), for use in the production of a screwed flange connection (35), in order to bring a tensioning tool (13) into a tensioning position in which it is in engagement with a screw bolt connection (18) to be pretensioned, or into a transport position in which it is out of engagement with a screw bolt connection and can be transported to the next screw bolt connection, wherein the flange (36a, 36b) extends horizontally, comprising a frame (2) for picking up and for lifting a load (13), a holding device (3) for holding the load, wherein the holding device is movable relative to the frame in the lifting direction (8), and comprising a hoisting device (4) for lifting and lowering the holding device (3) with the load (13) attached thereto, wherein the frame (2) is mounted on a first and a second support bearing (5, 6) and the first support bearing (5) is designed for abutment against the flange upper side (14), the frame (2) is designed to extend from the flange upper side (14) along the flange face (15) to below the flange underside (16), the second support bearing (6) is designed for abutment against the flange upper side (14) or against the flange face (15), the holding device (3) is equipped to hold the tensioning tool (13) below the flange underside (16) with the engaging means directed upwards, and the hoisting device (4) is equipped to lift the holding device (3) with the tensioning tool (13) attached thereto from a lowered transport position into a tensioning position.

For tightening screw connections disposed along two annular flanges to be tensioned relative to one another and forming a ring, a tool carrier movable along the ring has a tool and a sensor. It is moved along the ring at least once, wherein current longitudinal positions of the tool carrier relative to the ring are repeatedly detected as position values and the gap size between the annular flanges at the respective current position is repeatedly detected as a gap size value by the sensor. These values are transmitted to a control and evaluation unit storing gap size values conjointly with assigned position values as datasets and determining, based on the datasets, the largest or an above-average gap size value together with assigned position value as a primary position. The screw connection at the primary position or a directly adjacent one in circumferential direction is tightened by the tool.

Provided is a displaceable maintenance device, to a displaceable assembly device, to a method for servicing a fastening element, and to a method for servicing and/or assembling a fastening element of a flange of a wind power installation tower. Provided is a displaceable maintenance device for a wind power installation tower, comprising a mobile unit which is specified for moving the maintenance device along a flange of the wind power installation tower; a first maintenance unit having an impact element for impacting a fastening element, in particular a flange connection element, and a noise-receiver unit for detecting a noise generated by the impacting; a control unit for evaluating the noises detected by means of the noise-receiver unit, said control unit, based on the evaluation, being specified for assigning a maintenance status to a fastening element.

For tightening screwed connections by a multi-screwing device with first and second screwing tools, each with rotary drive for screwing an exchangeable bushing on and off, a device for longitudinally straining a threaded bolt, and a tool for retightening the nut, the screwing tools are moved at right angles relative to tool axes by an actuating drive. When the bushings of the screwing tools are both screwed onto a threaded bolt, these steps are performed: a) bushing of first screwing tool is unscrewed from threaded bolt and raised; b) first screwing tool is moved relative to the second into a position in which tool axis of first screwing tool is aligned with screw axis of a further threaded bolt; c) first screwing tool is lowered and screwed onto further threaded bolt; d) threaded bolt is longitudinally strained, and e) steps a) to d) are repeated for second tool.

A bolt installation and removal (BIR) system is used for assembling and disassembling a nuclear vessel. The BIR system includes a platform with a stand for supporting the nuclear vessel. A track extends around an outside perimeter of the platform and multiple tool carts include wheels that roll on the track. Tool towers are located on the carts and include tool assemblies configured to install and remove bolts on the nuclear reactor vessel. Magazine towers also extend up from the tool carts next to the tool towers and include magazines that hold bolts for exchanging with the tool assemblies. Drive mechanisms move tool heads in the tool assemblies around a first vertical axis, vertically up and down, and laterally to more simply and reliably install and remove the bolts in a radioactive underwater environment.

Tightening device can fasten a fastening element by a target tightening force with good accuracy and facilitate automation. The tightening device includes a cylindrical drive socket holding a nut in the lower end opening thereof; a nut holder disposed inside the drive socket, a bolt passing through a bottom thereof, and regulating movement of the nut held by the drive socket toward the tip end of a threaded par; a tension rod which is disposed inside the nut holder and the lower end face of which has a threaded hole into which a portion of the threaded part that is further on the tip end side than the nut is screwed; a sensor for detecting tension force; a first motor for turning the tension rod around an axis that extends in the vertical direction; and a second motor for turning the drive socket around an axis.

Robot (1) to tighten a series of nuts (2) pre-screwed on bolts (3) arranged in a curved flange connection (4), which bolts (3) project from the nuts (2) pre-screwed in substantially a nut plane (13) by a projection length (15), which robot (1) comprises a drive to move the robot (1) along the curved flange connection (4) and a tool (10) to tighten the nuts (2) with a predefined torque both connected to a support platform (6), characterized in that the tool (10) is built to screw a tension nut (26) onto the bolt (3) to elongate the bolt (3) and to tighten the pre-screwed nut (2) with a predefined torque with a tightening wheel (35), which robot (1) comprises positioning means to substantially align the axis (28) of the tension nut (26) with the axis (14) of the bolt (3) by lowering the tool (10) onto the bolt (3) in order to screw the tension nut (26) onto the bolt (3).

Provided is a nut and a bolt tightening method for fastening an object, wherein a tightening force is applied on the object by rotating a nut or a bolt in a state in which a predetermined tension force is applied on the bolt in the axial direction of the bolt. When the tensile force exerted on the bolt decreases as the tightening force increases and after a timing when an inflection point occurs in a time course change in a ratio of an amount of change in the tensile force exerted on the bolt to an amount of change in an angle of rotation of the nut or the bolt, the tightening resulting from the rotation of the nut or bolt is terminated and the tensile force applied on the bolt is removed.