Main shaft fixture

Abstract

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.

What is claimed is: 
     
         1 . A self-hoisting crane comprising:
 mounting facilities for mounting to a lightweight crane,   a winch located on a ground surface near a foot of the wind turbine, and   a main shaft fixture for fixation of a main shaft on a wind turbine during execution of installation and repair work on heavy parts of a wind turbine, the fixture being divided up into a number of sections for mounting on stable structural parts in a wind turbine nacelle including a bottom frame of the nacelle, wherein the main shaft fixture comprises at least three independently, radially displaceable pressure mandrels for fixing of cylinder-shaped shafts with different diameters and for the fixing of shafts with conical shapes, the pressure mandrels being substantially symmetrical located around a center axis, first ends of said pressure mandrels, in use, facing the main shaft and being furnished with a tap shoe, wherein said pressure mandrels are displaceable between a passive, withdrawn lockable, position where the tap shoes are configured to be located at a distance from the surface of the main shaft and an advanced lockable position where the tap shoes are configured to be engaged with the main shaft, in use, said tap shoes enabling the main shaft to be fixed in position by the main shaft fixture while being permitted to rotate.   
     
     
         2 . The self-hoisting crane according to  claim 1 , wherein the pressure mandrels ( 18 ) are provided with actuators for displacing and retaining the tap shoes ( 20 ) in the passive position and the active position, respectively, or in a selectable position between the passive and the active position. 
     
     
         3 . The self-hoisting crane according to  claim 1 , wherein the pressure mandrels ( 18 ) are comprised of threaded bolts having opposing free ends that face the main shaft and are furnished with tap shoes ( 20 ), and wherein said threaded bolts cooperate with threaded holes in respective sections of the fixture ( 10 ). 
     
     
         4 . The self-hoisting crane according to  claim 1 , wherein slide plates ( 42 ,  44 ) are located between the opposing sides of the surface of the main shaft and tap shoes. 
     
     
         5 . The self-hoisting crane according to  claim 4 , wherein the slide plates are configured so that the opposing free ends of the tap shoes ( 20 ) facing the main shaft ( 4 ) are provided with a one of the slide plates ( 42 ) which in an active advanced position is engaged with the main shaft ( 4 ). 
     
     
         6 . The self-hoisting crane according to  claim 5 , wherein one of the slide plates is a multi-part slide plate ( 44 ) cooperating with the main shaft ( 4 ) for mounting on the main shaft ( 4 ), where the multi-part slide plate ( 44 ) in a mounted position on the main shaft ( 4 ) cooperates with the tap shoes ( 20 ). 
     
     
         7 . The self-hoisting crane according to  claim 1 , further comprising a rotor lock ( 24 ) for fixation of the rotor ( 8 ) of the wind turbine. 
     
     
         8 . A self-hoisting crane with a main shaft fixture ( 10 ) for fixation of a main shaft ( 4 ) on a wind turbine during execution of installation and repair work on heavy parts of a wind turbine, where the fixture ( 10 ) is divided up into a number of sections for mounting on stable structural parts ( 2 ) in a nacelle in a wind turbine, including the bottom frame ( 2 ) of the nacelle, wherein the main shaft fixture ( 10 ) comprises at least three radially displaceable pressure mandrels ( 18 ), substantially symmetrical located around a center axis ( 11 ) of the main shaft, first ends of said pressure mandrels ( 18 ) face the main shaft ( 4 ) and are furnished with a tap shoe ( 20 ), and wherein said pressure mandrels ( 18 ) are displaceable between a passive, withdrawn lockable position where the tap shoes ( 20 ) are configured to be located at a distance from the surface of the main shaft ( 4 ) and an advanced lockable position where the tap shoes ( 20 ) are configured to be engaged with the main shaft ( 4 ), further comprising a rotor lock ( 24 ) for fixation of the rotor ( 8 ) of the wind turbine, further comprising one of a multi-part needle bearing, roller bearing, or ball bearing ( 46 ) comprised of a multi-part inner ring ( 48 ) fastened to the main shaft ( 4 ), and a therewith cooperating multi-part outer ring ( 50 ) comprised of bowed sub-segments ( 52 ) corresponding to the number of tap shoes, mounted on the opposing side of the tap shoes ( 20 ) facing the inner ring ( 48 ), which in the advanced active position of the pressure mandrels form the outer ring ( 50 ) at a distance from the outer periphery of the multi-part inner ring ( 48 ), and where a plurality of needle rollers, rollers, or balls ( 54 ) are arranged between the inner ring ( 48 ) and the outer ring ( 50 ), and where means are present for retaining the needles, rollers, or balls ( 54 ) in position between the inner ring ( 48 ) and outer ring ( 50 ). 
     
     
         9 . The self-hoisting crane according to  claim 8 , wherein main shaft fixture ( 10 ) is connected by mounting facilities ( 40 ) the crane ( 12 ).