Patent Publication Number: US-11661924-B2

Title: Rotor lock for wind turbine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 17/271,334 filed Feb. 25, 2021, which is a national entry of PCT/CA2019/051174 filed Aug. 27, 2019, which claims the benefit of United States Provisional Patent Application U.S. Ser. No. 62/725,885 filed Aug. 31, 2018, the entire contents of all of which are herein incorporated by reference. 
    
    
     FIELD 
     This application relates to wind turbines, in particular to a lock for preventing rotation of a rotor during maintenance of the wind turbine. 
     BACKGROUND 
     Replacement or repair of wind turbine components, in particular wind turbine components connected to a rotor of the wind turbine, is difficult because the rotor may continue to rotate in the wind while attempts are made to effect replacement or repair of the component. Components connected to a rotor include, for example, the main shaft, the gearbox, the generator and the like. To prevent the rotor from rotating during replacement or repair of such components, the rotor may be locked down to prevent rotation. However, different kinds of lock mechanisms have been used depending on the particular component to be replaced or repaired because there are limited locations at which to effectively mount a lock and existing locks are often mounted on the very component that is desired to be replaced or repaired. Further, many existing locks are cumbersome or difficult to install and/or use. 
     There remains a need for a rotor lock that is easier to install and use and that can be used to lock a rotor irrespective of what turbine component is to be replaced or repaired. 
     SUMMARY 
     In one aspect, there is provided a lock for preventing rotation of a rotor of a wind turbine, the lock comprising: a pin support supportable on main bearing supports or main bearing support extensions in a nacelle of the wind turbine, the pin support comprising a beam and first and second clamps situated proximate ends of the beam, the clamps mountable on the main bearing supports or main bearing support extensions, the beam comprising a hub-facing face proximate a rotor hub of the wind turbine and a gearbox-facing face opposite the hub-facing face when the pin support is supported on the main bearing supports or main bearing support extensions, the beam further comprising support apertures through the beam extending between the hub-facing face and a gearbox-facing face; first and second rotatable lock pins inserted through the support apertures to rotatably mounted the lock pins on the pin support, each lock pin comprising a first cylindrical portion having a first central axis rotatably mounted through one of the support apertures and a cammed portion comprising a second cylindrical portion having a second central axis, the second cylindrical portion having a smaller diameter than the first cylindrical portion, the second cylindrical portion extending from an end of the first cylindrical portion such that the first and second central axes are not colinear, the cammed portion protruding from and extending away from the hub-facing face of the pin support toward the hub, the first cylindrical portion protruding from the gearbox-facing face, the lock pins inserted into complementary first and second rotor lock apertures, respectively, on the rotor hub when the pin support is supported on the main bearing supports or main bearing support extensions; first and second lock pin brackets, the first lock pin connected to the first bracket proximate a first end of the first bracket, the second lock pin connected to the second bracket proximate a first end of the second bracket; and, a turnbuckle for rotating the lock pins, the turnbuckle comprising a frame and first and second ends, the first end of the turnbuckle connected to the first bracket proximate a second end of the first bracket, the second end of the turnbuckle connected to the second bracket proximate a second end of the second bracket, whereby rotation of the frame of the turnbuckle causes the second end of the first bracket and the second end of the second bracket to move arcuately thereby causing the first and second lock pins connected proximate the first ends of the first and second brackets to rotate so that exterior surfaces of the cammed portions engage with interior surfaces of the complementary apertures to apply forces in opposite directions at the interior surfaces of the apertures to immobilize the lock pins in the respective apertures against the interior surfaces to prevent relative motion between the lock pins and the apertures to prevent rotation of the rotor. 
     In another aspect, there is provided a lock for preventing rotation of a rotor of a wind turbine, the lock comprising: a pin support supportable in a nacelle of the wind turbine, the pin support having a hub-facing face proximate a rotor hub of the wind turbine when the pin support is supported in the nacelle; a rotatable lock pin rotatably mounted on the pin support, the lock pin having a cammed portion extending away from the hub-facing face of the pin support toward the hub, the lock pin inserted into a complementary rotor lock aperture on the rotor hub when the pin support is supported in the nacelle, rotation of the lock pin causing engagement of an exterior surface of the cammed portion with an interior surface of the aperture to immobilize the lock pin against the interior surface of the aperture to prevent relative motion between the lock pin and the aperture to prevent rotation of the rotor; and, a mechanism for rotating the lock pin. 
     In another aspect, there is provided a lock for preventing rotation of a rotor of a wind turbine, the lock comprising: a pin support supportable in a nacelle of the wind turbine, the pin support having a hub-facing face proximate a rotor hub of the wind turbine when the pin support is supported in the nacelle; first and second rotatable lock pins rotatably mounted on the pin support, each of the lock pins having a cammed portion extending away from the hub-facing face of the pin support toward the hub, the lock pins inserted into complementary first and second rotor lock apertures, respectively, on the rotor hub when the pin support is supported in the nacelle, rotation of the lock pins causing engagement of exterior surfaces of the cammed portions with interior surfaces of the complementary apertures to immobilize the lock pins against the interior surfaces of the apertures to prevent relative motion between the lock pins and the apertures to prevent rotation of the rotor; and, a mechanism for rotating the lock pins. 
     Rotation of one or more cam-shaped pins fitted into one or more complementary rotor lock apertures on the rotor hub forces the one or more cam-shaped pins into engagement with interior surfaces of the apertures to secure the rotor. The camming action effectively wedges the cam-shaped pins in the rotor lock apertures to prevent any play between the pins and the apertures. In an embodiment, the rotor lock apertures may be existing rotor lock apertures on the rotor hub. In an embodiment, the one or more cam-shaped pins may be rotated by a turnbuckle, preferably one turnbuckle connected to two pins. 
     In an embodiment, the lock pin comprises a first cylindrical portion rotatably mounted through a support aperture in the pin support. The first cylindrical portion has a first central axis. In an embodiment, the cammed portion of the lock pin is a second cylindrical portion of the lock pin. The second cylindrical portion has a second central axis. In an embodiment, the second cylindrical portion has a different diameter, preferably a smaller diameter, than the first cylindrical portion. In an embodiment, the second cylindrical portion extends from an end of the first cylindrical portion such that the first and second central axes are not colinear. In an embodiment, the lock pin is rotatable about the first central axis, the second central axis rotating about the first central axis when the pin is rotated. In an embodiment, rotation of the lock pin about the first central axis causes the cammed portion, for example the second cylindrical portion, to move laterally across the rotor lock aperture to engage or disengage from the interior surface of the rotor lock aperture. 
     In an embodiment, the mechanism for rotating the lock pin comprises a turnbuckle. In an embodiment, the turnbuckle is linked to the lock pin such that rotation of a frame of the turnbuckle causes rotation of the lock pin. In an embodiment, the mechanism for rotating the lock pin comprises a lock pin bracket, the lock pin connected to the bracket. In an embodiment, the lock pin is connected to the lock pin bracket proximate a first end of the bracket and the turnbuckle is connected to the lock pin bracket proximate a second end of the bracket. In an embodiment, rotation of the frame of the turnbuckle causes the second end of the bracket to move arcuately thereby causing the lock pin connected proximate the first end of the bracket to rotate. In an embodiment, when the lock pin is rotated, the lock pin applies a force on the interior surface of the rotor lock aperture to immobilize the lock pin the rotor lock aperture. 
     In an embodiment, the lock pin comprises first and second lock pins. In an embodiment, the mechanism for rotating the lock pin comprises first and second lock pin brackets. In an embodiment, the first lock pin is connected to the first lock pin bracket proximate a first end of the first bracket. In an embodiment, the turnbuckle comprises a first end and a second end. In an embodiment, the first end of the turnbuckle is connected to the first bracket proximate a second end of the first bracket. In an embodiment, the second lock pin is connected to the second bracket proximate a first end of the second bracket. In an embodiment, the second end of the turnbuckle is connected to the second bracket proximate a second end of the second bracket. In an embodiment, rotation of the frame of the turnbuckle causes the second end of the first bracket and the second end of the second bracket to move arcuately thereby causing the first and second lock pins connected proximate the first ends of the first and second brackets to rotate. In an embodiment, when rotated, the first and second lock pins apply force at the interior surfaces of the first and second apertures in opposite directions to immobilize the lock pins in the respective apertures. 
     In an embodiment, the pin support comprises fasteners for securing the pin support on the main bearing supports or main bearing support extensions. In an embodiment, the pin support comprises a beam. In an embodiment, the fasteners comprise first and second clamps situated proximate ends of the beam. In an embodiment, the clamps are mountable on the main bearing supports or main bearing support extensions. In an embodiment, the support aperture for each lock pin is a through aperture through the beam between the hub-facing face and a gearbox-facing face of the beam. In an embodiment, the lock pin is inserted through the through aperture so that the cammed portion protrudes from the hub-facing face and the first cylindrical portion protrudes from the gearbox-facing face. In an embodiment, the pin support is supportable on main bearing supports or main bearing support extensions in the nacelle. Being mountable on the main bearing supports or main bearing support extensions, the rotor lock is useable to lock the rotor irrespective of the turbine component to be replaced or repaired. 
     Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG.  1    depicts a rear perspective view of an interior of a nacelle showing existing rotor hub flange, main bearing, main bearing supports and main rotor shaft of a wind turbine; 
         FIG.  2    depicts a rear perspective view of the nacelle of  FIG.  1    further showing a rotor lock of the present invention supported on the main bearing supports; 
         FIG.  3    depicts a side perspective view of  FIG.  2   ; 
         FIG.  4    depicts a rear view of  FIG.  2   ; 
         FIG.  5    depicts  FIG.  2    with the rotor lock in a fully open configuration; 
         FIG.  6    depicts a front view of  FIG.  5   ; 
         FIG.  7    depicts a top view of  FIG.  5   ; 
         FIG.  8    depicts  FIG.  2    with the rotor lock in a fully closed configuration; 
         FIG.  9    depicts a front view of  FIG.  8   ; 
         FIG.  10    depicts a rear perspective view of the rotor lock shown in  FIG.  2   ; 
         FIG.  11    depicts a rear view of the rotor lock of  FIG.  10   ; 
         FIG.  12    depicts a top view of the rotor lock of  FIG.  10   ; 
         FIG.  13    depicts a rear view of a rotor lock main disk of the rotor lock of  FIG.  10   ; 
         FIG.  14    depicts a top view of the rotor lock main disk of  FIG.  13   ; 
         FIG.  15    depicts a rear perspective view of a rotor lock pin of the rotor lock of  FIG.  10   ; 
         FIG.  16    depicts a front view of the rotor lock pin of  FIG.  15   ; 
         FIG.  17    depicts a top view of the rotor lock pin of  FIG.  15   ; 
         FIG.  18    depicts a rear perspective view of a rotor lock pin bracket of the rotor lock of  FIG.  10   ; 
         FIG.  19    depicts a side view of the rotor lock pin bracket of  FIG.  18   ; and, 
         FIG.  20    depicts a rear view of the rotor lock pin bracket of  FIG.  18   . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , a nacelle of a wind turbine houses a bed plate  101 , a gear box  102 , a main rotor shaft  103 , a main bearing  104 , main bearing supports  105  and a rotor hub flange  106  having a plurality of rotor lock apertures  107  (only one labeled), as is known in the prior art. 
     Referring to the Figures, a rotor lock  1  of the present invention is mountable on main bearing support extensions  5 , the main bearing support extensions  5  being brought up to the nacelle and mounted on the main bearing supports  105  to provide locations on which cranes and other accessories may be temporarily mounted in the nacelle. The rotor lock  1  comprises a main disk, for example a beam  10  as illustrated although other forms of main disk are possible, having a longitudinal axis that extends laterally across the nacelle between the main bearing supports  105  over the rotor bearing  104  proximate to and to a rear face of the rotor hub flange  106 . The beam  10  comprises spaced-apart eye plates  13  for connection to a lifting apparatus to permit lifting the rotor lock  1  up to the nacelle and positioning the rotor lock  1  on the main bearing support extensions  5 . 
     Ends of the beam  10  are equipped with clamps  20  that secure the rotor lock  1  to protrusions extending forwardly from the main bearing support extensions  5 . Each clamp  20  comprises a bolt plate  21  and a shim plate  22  between which the protrusion is clamped, and a plurality of bolts  23  inserted through bolt holes  24  extending between top and bottom surfaces of the beam  10 . The bolts  23  extend through corresponding apertures in a pressure plate  25  on the top surface of the beam  10 , and extend into threaded apertures in a top surface of the bolt plate  21 . Tightening the bolts  23  provides the pressure to clamp the protrusions between the bolt plates  21  and shim plates  22  to secure the rotor lock  1  on the main bearing support extensions  5 . The rotor lock  1  may be dismounted by loosening the bolts  23 . 
     The beam  10  comprises two spaced-apart pin support apertures  12 , which are aligned with two corresponding rotor lock apertures  107  in the rotor hub flange  106  when the rotor lock  1  is mounted on the main bearing support extensions  5 . Lock pins  30  extend through the pin support apertures  12 , one end of each lock pin  30  protruding rearwardly from a rear face of the beam  10  and another end of each lock pin  30  protruding forwardly from a front face of the beam  10 . Each pin  30  comprises a first portion  31  and a second portion  32 . The first portion  31  occupies and is rotatable within the pin support aperture  12 , and protrudes rearwardly from the rear face of the beam  10 . The second portion  32  protrudes forwardly from the front face of the beam  10 . With the rotor lock  1  mounted on the main bearing support extensions  5 , the second portion  32  extends into one of the rotor lock apertures  107  in the rotor hub flange  106 . While two lock pins are illustrated, one lock pin or more than two lock pins may be employed instead. Shims between bottoms of the bolt plates  21  of the clamps  20  and the main bearing support extensions  5  may be used to adjust tightness of the lock pins  30  in the rotor lock apertures  107 . 
     As best seen in  FIG.  16    and  FIG.  17   , the first portion  31  has a larger diameter than the second portion  32 . Further, a center C 32  of the second portion  32  is offset from a center C 31  of the first portion  31  so that central axes A 31 , A 32  of the first and second portions  31 ,  32 , respectively, are parallel but not colinear. When the lock pin  30  rotates, the lock pin  30  rotates about the axis through C 31  with the axis through C 32  also rotating about the axis C 31 . Perimeters of the first and second portions  31 ,  32  may share a common point P, but the perimeter of the second portion  32  does not extend beyond the perimeter of the first portion  31 . While the two perimeters may share a common point, in some embodiments the perimeter of the second portion  32  may be wholly inside the perimeter of the first portion  31 . When the lock pin  30  is rotated the second portion  32 , the center C 32  follows a path that describes an arc around the center C 31 . When the second portion  32  extends into one of the rotor lock apertures  107 , rotation of the lock pin  30  also results in movement of the second portion  32  laterally inside the rotor lock aperture  107 . Lateral movement of the second portion  32 , i.e. camming action, brings an outside surface  33  of the second portion  32  into contact with an inner surface  107   a  (see  FIG.  1   ) of the rotor lock aperture  107 . Maintaining contact between the outside surface  33  of the second portion  32  and the inner surface  107   a  of the rotor lock aperture  107  arrests rotation of the rotor thereby locking the rotor in place. The rotor can be released by reversing the rotation of the lock pin  30  to disengage the outside surface  33  of the second portion  32  from the inner surface  107   a  of the rotor lock aperture  107 . While the first and second portions  31 ,  32  of the lock pin  30  are shown as cylinders, the second portion  32  could be some other shape, for example elliptical, that can be inserted into the rotor lock aperture  107  and engage the inner surface  107   a  of the rotor lock aperture  107  when the lock pin  30  is rotated. 
     The lock pins  30  may be rotated by a pin rotating mechanism  40  comprising a force applicator, for example a turnbuckle  41  as illustrated or some other device for applying force such as a lever or a crank. The turnbuckle  41  comprises a frame  42  having threaded apertures at each end through which jaw bolts are threaded. The jaw bolts are pivotally connected to ends of lock pin brackets  44 , the lock pin brackets  44  connected by bolts  45  inserted through bracket apertures  46  to the lock pins  30 . The bolts  45  are threaded into bolt holes  36  in rear ends  37  of the first portions  31  of the lock pins  30 . For greater security, the rear ends  37  of the first portions  31  of the lock pins  30  comprise channels 38 sized to snugly fit the lock pin brackets  44  therein. 
     Rotation of the frame  42  of the turnbuckle  41  causes the jaw bolts to extend or retract thereby causing the ends of the lock pin brackets  44  to translate, which in turn causes the lock pins  30  to rotate.  FIG.  5    to  FIG.  7    show the rotor lock  1  in a fully open configuration where the ends of the lock pin brackets  44  are pushed slightly but not fully apart from vertical, whereas  FIG.  8    and  FIG.  9    show the rotor lock  1  in a first fully closed configuration where the ends of the lock pin brackets  44  are pulled together from the vertical. A second fully closed configuration occurs when the lock pin brackets  44  are pushed fully apart from the vertical. As best seen in  FIG.  6   , in the fully open configuration, it is possible to insert and retract the lock pins  30  into and out of the rotor lock apertures  107 , and there is some tolerance between the outside surfaces  33  of the second portions  32  of the lock pins  30  and the inner surfaces  107   a  of the rotor lock apertures  107  so that the rotor is capable of some, if only a small amount of, rotational movement. As best seen in  FIG.  9   , in the first fully closed configuration, the outside surfaces  33  of the second portions  32  of the lock pins  30  are engaged with the inner surfaces  107   a  of the rotor lock apertures  107  so that the rotor cannot rotate, the turnbuckle  41  holding the ends of the lock pin brackets  44  in place to prevent the lock pins  30  from rotating even a small amount. In the first fully closed configuration, force is applied against the inner surfaces  107   a  of the rotor lock apertures  107  by the outside surfaces  33  of the second portions  32  of the lock pins  30  in opposite directions. As seen in  FIG.  9   , the second portion  32  of the right-side lock pin  30  is engaged with the inner surface  107   a  of the right-side rotor lock aperture  107  on the right side, while the second portion  32  of the left-side lock pin  30  is engaged with the inner surface  107   a  of the left-side rotor lock aperture  107  on the left side. The forces applied by the lock pins  30  in the rotor lock apertures  107  are therefore in the opposite direction away from each other. In the second fully closed configuration, the second portion  32  of the right-side lock pin  30  is engaged with the inner surface  107   a  of the right-side rotor lock aperture  107  on the left side, while the second portion  32  of the left-side lock pin  30  is engaged with the inner surface  107   a  of the left-side rotor lock aperture  107  on the right side. The forces applied by the lock pins  30  in the rotor lock apertures  107  are therefore in the opposite direction toward each other. The first fully closed configuration is preferred in use. 
     The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.