Disclosed are a power transfer device for transferring external power to a rotary body, a pipe cutting device using the power transfer device and a hydraulic chucking device using the power transfer device. The power transfer device is configured to transfer external power to a rotary body coupled to one side of a main body. The power transfer device includes at least one double-action interlocking cylinder mounted to a rear surface of the rotary body and provided with a rod protruding toward the main body, a push unit installed in the main body and provided with at least one pusher protruding toward the rotary body, and a bearing disposed between the pusher of the push unit and the rod of the interlocking cylinder and configured to allow relative rotation of the pusher and the rod and to transfer power between the pusher and the rod.

A chuck for clamping workpieces or tools in a clamping space with a clamping force (F). The chuck includes at least two chuck jaws movable in translation along one clamping plane (E) in the direction of one center Z of the clamping space and a gear train located at least largely within the chuck for transfer of a driving torque of a drive motor, which can be coupled to the gear train by coupling means of the gear train, to the chuck jaws for movement of the chuck jaws. The coupling means able to be coupled to a corresponding coupling connection of the drive motor. The movement from the maximum size of the clamping space to the minimum size of the clamping space is executed via the gear train from the drive motor.

A work holder includes: a first holding part having three attracting members that are arranged circumferentially apart from each other to attract an axial end face of an annular work; and a second holding part having a contacting member that is held in contact with an inner periphery or outer periphery of the work and restricts radial movement of the work.

A chuck for clamping workpieces or tools in a clamping space with a clamping force (F). The chuck includes at least two chuck jaws movable in translation along one clamping plane (E) in the direction of one center Z of the clamping space and a gear train located at least largely within the chuck for transfer of a driving torque of a drive motor, which can be coupled to the gear train by coupling means of the gear train, to the chuck jaws for movement of the chuck jaws. The coupling means able to be coupled to a corresponding coupling connection of the drive motor. The movement from the maximum size of the clamping space to the minimum size of the clamping space is executed via the gear train from the drive motor.

A main shaft fixture for fixing a main shaft on a wind turbine during installation and repair work on heavy parts of the wind turbine nacelle, in the case where the fixture is formed of several sections for mounting on stable structural parts in the nacelle, including the nacelle's bottom frame. The main shaft fixture has adjustable pressure mandrels with tap shoes, which cause the fixture to be usable regardless of the turbine main shaft geometry, such that it can be mounted without fixing the rotor. The main shaft fixture also has facilities for mounting of a lightweight crane and a self-hoisting crane with a ground-based winch, respectively, as well as a rotor lock which, in combination with actuators of the main shaft fixture, enables the main shaft and the main shaft bearing to be sufficiently displaced vertically from its bearing in the nacelle to service or replace the bearing.

A fluid-operated gripping apparatus for holding a workpiece having a curved sidewall in a working orientation, and associated methods for gripping and holding a workpiece, are provided. Three fluid-operated actuators, each including an actuator rod and a moveable piston arranged within a cylinder, are equally spaced around a perimeter of a workpiece and receive fluid from a single pressurized fluid source. A fluid (e.g., hydraulic or pneumatic) circuit causes the actuators to extend during a closing stroke of the gripping apparatus according to the force equalization principle. Each actuator includes an end effector pivotally coupled with an actuator rod and configured to contact a surface of the workpiece at exactly two points. A backstop configured to contact an end face of the workpiece is coupled with a rotational joint.

Disclosed are a power transfer device for transferring external power to a rotary body, a pipe cutting device using the power transfer device and a hydraulic chucking device using the power transfer device. The power transfer device is configured to transfer external power to a rotary body coupled to one side of a main body. The power transfer device includes at least one double-action interlocking cylinder mounted to a rear surface of the rotary body and provided with a rod protruding toward the main body, a push unit installed in the main body and provided with at least one pusher protruding toward the rotary body, and a bearing disposed between the pusher of the push unit and the rod of the interlocking cylinder and configured to allow relative rotation of the pusher and the rod and to transfer power between the pusher and the rod.

A chuck for clamping workpieces or tools in a clamping space with a clamping force (F). The chuck includes at least two chuck jaws movable in translation along one clamping plane (E) in the direction of one center Z of the clamping space and a gear train located at least largely within the chuck for transfer of a driving torque of a drive motor, which can be coupled to the gear train by coupling means of the gear train, to the chuck jaws for movement of the chuck jaws. The coupling means able to be coupled to a corresponding coupling connection of the drive motor. The movement from the maximum size of the clamping space to the minimum size of the clamping space is executed via the gear train from the drive motor.

A toolholder for a tool having a flat surface that can be rotated about an axis of rotation, in particular, a Weldon toolholder for a milling tool or a core drill. A clamping jaw has a contact surface spaced from the flat surface side of the flat surface and touches the flat surface when the clamping jaw is pressed against the flat surface in a second arrangement of the clamping jaw or in the assembly position of the tool. A stationary machine tool comprising this toolholder and a tool and a method for manufacturing thereof are also provided.