Abstract:
A packing for wind power turbine blades having at least one inflatable annular structure, which in turn has a flat outer supporting wall, and inner clamping walls for clamping a blade in a designated position with respect to the outer supporting wall. A method of packing wind power turbine blades which includes applying at least one inflatable annular structure about a blade, and causing the at least one inflatable annular structure to inflate to distend at least one outer supporting wall and at least one inner clamping wall to clamp the blade.

Description:
PRIORITY CLAIM 
     This application claims the benefit of and priority to Italian Patent Application No. MI2009A 000119, filed on Jan. 30, 2009, the entire contents of which are incorporated herein. 
     BACKGROUND 
     A wind power turbine blade is an elongated member comprising a metal structure embedded in a fiberglass shell. Currently used blades may be as long as 50 meters or 164 feet, and comprise, in succession, a connection, root, wing, and tip. The root of the blade has a substantially circular cross section that varies considerably along the blade axis, while the wing has a cross section in the form of a wing profile that varies considerably in shape and size along the blade axis. 
     Because of its shape and size, a wind power turbine blade is relatively difficult to pack and transport. 
     Accordingly, special packing has been devised for transporting, handling, and storing wind power turbine blades. For example, EP Patent Application No. 1,829,762 A1 relates to packing for transporting wind power turbine blades. Since a wind power turbine is normally equipped with three identical blades equally spaced about the hub rotation axis, the packing described in EP Patent Application No. 1,829,762 A1 is designed to house three blades, and substantially comprises a metal trellis structure that extends the full length of the blades and comprises three compartments, each for housing a respective blade. 
     However, the packing described in EP Patent Application No. 1,829,762 A1 has the drawback of being extremely heavy, bulky, and relatively expensive. Moreover, once the blades are delivered to the installation site, the packing must be returned to the manufacturing plant, the expense of which may be enormous, in view of the fact that blades are at times shipped to sites thousands of kilometers or miles from the manufacturing plant. 
     To reduce the size and weight of the packing, PCT Patent Application No. WO 2006/061806 A2 describes packing comprising small metal supporting structures placed only along given portions of the blades. 
     Additionally, U.S. Published Patent Application No. 2008/0107526 relates to packing for supporting one blade, and which comprises a metal container, and protective cushions between the metal container and the blade. The metal container comprises a universal joint, and serves to move the blade as it is assembled to the hub. 
     Though some of the these known types of packing are relatively small, they still only partly solve the problem of returning the packing, which still involves transporting relatively bulky metal structures at a relatively high cost. 
     Moreover, such known packing is difficult to apply to the blade/s, and must be applied with great care to avoid damaging the blades. 
     SUMMARY 
     The present disclosure relates to packing for wind power turbine blades. More specifically, the present disclosure relates to a packing, a protector or a transportor configured to support a wind power turbine blade, to facilitate transport of the blade, and to protect the blade from shock during transport. 
     One object of the present disclosure is to provide lightweight, compact packing for wind power turbine blades. 
     Another object of the present disclosure is to provide wind power turbine blade packing designed to reduce the cost of returning the packing. 
     Another object of the present disclosure is to provide wind power turbine blade packing that can be applied easily to the blade. 
     According to one embodiment of the present disclosure, there is provided packing for wind power turbine blades, the packing comprising at least one inflatable annular structure comprising at least one outer supporting wall (such as at least one flat outer supporting wall), and at least one inner clamping wall for clamping a blade in a given or designated position with respect to the outer supporting wall. 
     The inflatable annular structure is lightweight and compact, can be deflated to return the packing, and, when fully or partly deflated, can be fitted easily about the blade and then inflated to secure it to the blade, so the blade can be positioned much more easily with respect to it. 
     The inflatable annular structure is also extremely versatile, by adapting to the different cross sections of a given blade, and can be used for packing blades of different shapes and sizes and at different positions along the blade. 
     In one embodiment of the present disclosure, the inflatable annular structure comprises at least one inflatable outer bag comprising the outer supporting wall and at least one inflatable inner bag comprising the inner clamping wall. 
     The inflatable outer and/or inner bag may thus be inflated selectively to simplify assembly of the packing to the blade. Accordingly, it should be appreciated that the present disclosure provides a packing, a protector or a transportor with a conformable or compressible engagement surface with adapts to the shape and size of the blade. 
     In another embodiment of the present disclosure, the inflatable outer bag comprises a plurality of substantially flat, adjacent outer supporting walls. 
     In this embodiment, a designated outer supporting wall can be selected, and the other outer supporting walls can be used for supporting other inflatable annular structures. 
     Another object of the present disclosure is to provide an easy method of packing wind power turbine blades. 
     According to one embodiment of the present disclosure, there is provided a method of packing wind power turbine blades, the method comprising the steps of applying at least one inflatable annular structure about a blade, and inflating the inflatable annular structure to distend an outer supporting wall (such as a flat outer supporting wall), and an inner clamping wall for clamping the blade. 
     Additional features and advantages are described in, and will be apparent from, the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A number of non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows a side view, with parts removed for clarity, of a blade being transported in wind power turbine blade packing in accordance with one embodiment of the present disclosure; 
         FIGS. 2 and 3  show larger-scale end views, with parts removed for clarity, of an inflatable annular structure of the  FIG. 1  packing; 
         FIG. 4  shows an end view, with parts removed for clarity, of a packing assembly comprising three connected packings; 
         FIG. 5  shows a larger-scale isometric view, with parts removed for clarity, of the inflatable annular structure in  FIG. 3 ; and 
         FIGS. 6 and 7  show end views, with parts removed for clarity, of two alternative embodiments of inflatable annular structures in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the example embodiments of the present disclosure illustrated in  FIGS. 1 to 7 , number  1  in  FIG. 1  indicates as a whole a packing, a protector or a transportor for a blade  2  of a known wind power turbine (not shown in the drawings). 
     A known wind power turbine (not shown in the drawings), normally comprises a blade assembly comprising a hub fitted with three blades equally spaced bout the hub rotation axis. 
     In the  FIG. 1  example, blade  2  is suspended from a helicopter  3  by two slings  4  and a hitch device  5 . 
     Blade  2  extends along a longitudinal axis A, and comprises, from left to right in  FIG. 1 , a connection  6 , a root  7 , and a wing  8  terminating in a tip  9 . Connection  6  has a substantially circular cross section, root  7  has a circular cross section varying along longitudinal axis A, and wing  8  has a cross section in the form of a wing profile that varies in size along longitudinal axis A. 
     Root  7  has an annular face  10 , and wing  8  has two faces  11 ,  12  ( FIG. 5 ) extending between root  7  and tip  9 . 
     Connection  6  comprises flanges, and a toothed ring nut forming a pitch control mechanism (not shown) to control the orientation of blade  2  about axis A when blade  2  is fitted to the hub. Blade  2  comprises a metal structure, and a fiberglass shell covering the metal structure, except for connection  6 . 
     In the  FIG. 1  example, packing  1  comprises two inflatable annular structures  13 , one applied about root  7 , and the other about wing  8 . 
     Each inflatable annular structure  13  is a load-bearing structure capable of supporting the weight of blade  2  and keeping blade  2  raised off a supporting surface P ( FIG. 3 ). 
     With reference to  FIG. 2 , each inflatable annular structure  13  comprises an annular inflatable outer bag  14 , and six inflatable inner bags  15 . Inflatable outer bag  14  is described in the distended configuration (i.e., inflated with gas, such as air) and comprises three adjacent outer supporting walls  16  which, in use, impart to inflatable annular structure  13  the shape of a triangular-ended prism, the lateral walls of which are defined by outer supporting walls  16 . Inflatable outer bag  14  also comprises three intermediate walls  17 , each parallel to and facing a respective supporting wall  16 , two end walls  18  (only one shown in  FIG. 2 ) connecting supporting walls  16  to intermediate walls  17 , a valve  19  for feeding gas into and expelling gas from inflatable outer bag  14 , and a cap  20  for closing valve  19 . Each inflatable inner bag  15  extends along an intermediate wall  17 . In the example shown, each intermediate wall  17  also defines a wall of an inflatable inner bag  15 . And at least two adjacent inflatable inner bags  15  extend along each intermediate wall  17 . 
     With reference to  FIG. 3 , in addition to a portion of intermediate wall  17 , each inflatable inner bag  15  also comprises two adjacent inner clamping walls  21 ,  22  parallel to axis A, two end walls  23  (only one shown in  FIG. 3 ) perpendicular to axis A, a valve  24 , and a cap  25 . 
     With reference to  FIG. 5 , outer supporting walls  16  comprise reinforcing panels  26 , such as reinforcing panels made of rubber, to also prevent inflatable annular structure  13  from slipping on supporting surface P ( FIG. 3 ). 
     Each inflatable annular structure  13  comprises one or more connectors, (such as flaps  27  in which reinforced-edged eyelets  28  are formed) which extend along the edges of each outer supporting wall  16  to connect one inflatable annular structure  13  to an adjacent inflatable annular structure  13 , as shown in  FIG. 4 . 
     In actual use, and with reference to  FIGS. 3 and 5 , inflatable outer bag  14  defines the shape of inflatable annular structure  13 , and in particular of outer supporting walls  16 , while inner bags  15  clamp and lock blade  2  in a given position with respect to inflatable outer bag  14 , and in particular with respect to outer supporting walls  16 . 
     More specifically, when inflatable inner bags  15  are inflated, inner clamping walls  21 ,  22  gradually move into position contacting faces  11  and  12  of wing  8  or the inner clamping walls  21 ,  22  of the adjacent inflatable inner bags  15 . 
     When inflatable annular structure  13  is fitted about root  7 , inflatable inner bags  15  adapt to the shape of root  7  and assume a different shape from the one shown in  FIGS. 3 and 5 . 
     With reference to  FIG. 6 , number  29  indicates an inflatable annular structure comprising an annular inflatable outer bag  14 , and three inflatable inner bags  30 , each comprising an inner clamping wall  31 , two end walls  32  (only one shown in  FIG. 6 ), a valve  33 , and a cap  34 . 
     With reference to  FIG. 7 , number  35  indicates an inflatable annular structure comprising an annular inflatable outer bag  14 , and an annular inflatable inner bag  36  comprising an annular inner clamping wall  37 , two end walls  38  (only one shown in  FIG. 7 ), a valve  39 , and a cap  40 . 
     Inflatable annular structures  29  and  35  are particularly suitable for clamping blade  2  at root  7 . Though inflatable annular structures  13 ,  29 ,  35  differ as to the shape and number of respective inflatable inner bags  15 ,  30 ,  36 , and each is preferable to the others in certain applications, inflatable annular structures  13 ,  29 ,  35  are interchangeable. 
     Like inflatable annular structures  13 , inflatable annular structures  29  and  35  also comprise one or more connectors, such as flaps  27  with reinforced-edged eyelets  28 . 
     With reference to  FIG. 1 , in addition to inflatable annular structures  13 , packing  1  comprises a cover  41  for protecting tip  9  of blade  2 , and which is in the form of a cap and also inflatable. 
     In one alternative embodiment of the present disclosure (not shown), the packing comprises further inflatable covers placed along other portions of the blade to protect the blade from shock. 
     Number  42  in  FIG. 4  indicates a packing assembly for three blades  2  packed in respective inflatable annular structures  13  fixed to one another. 
     In the  FIG. 4  example, two inflatable annular structures  13  rest on a supporting surface P along two respective outer supporting walls  16 , and a third inflatable annular structure  13  rests on the other two inflatable annular structures  13 . Because inflatable annular structures  13  are prism-shaped with triangular, such as isosceles triangular, ends, two side by side inflatable annular structures  13  form a gap complementary to the inverted third inflatable annular structure  13 , two outer supporting walls  16  of which rest on two sloping outer supporting walls  16  of the other two inflatable annular structures  13 . 
     The three inflatable annular structures  13  are connected to one another by rings  43  or ropes (not shown) through adjacent eyelets  28  of adjacent inflatable annular structures  13 . Packing assemblies of different shapes can thus be formed comprising at least two connected inflatable annular structures  13 . 
     The wind power turbine blade packing method comprises the steps of placing at least two inflatable annular structures  13  about a blade  2 , and inflating each inflatable annular structure  13  to distend outer supporting walls  16 , and inner clamping walls  21  or  22  for clamping blade  2 . 
     In one embodiment, the method comprises the step of inflating inflatable outer bag  14  first, and then inflatable inner bags  15 . More specifically, the method of this embodiment comprises the step of positioning inflatable annular structure  13  about blade  2  before inflating inflatable inner bags  15 , and after inflating inflatable outer bag  14 , so as to set supporting walls  16  in a given position with respect to blade  2 . 
     The method also comprises the step of placing inflatable annular structure  13  about blade  2  at a given point along axis A of blade  2 , before inflating inflatable inner bags  15  and after inflating inflatable outer bag  14 . 
     Once positioned correctly with respect to blade  2 , inflatable annular structure  13  is locked about blade  2  by inflating inflatable inner bags  15 , such as simultaneously. 
     The same packing method also applies to fitting inflatable annular structures  29  and  35  to blade  2 . 
     The present disclose has numerous advantages: packing, protector or transportor  1  substantially comprises lightweight, compact, relatively low-cost inflatable annular structures, the inflatable annular structures defining the packing can be salvaged and deflated to drastically reduce volume for transport from the blade installation site back to the blade manufacturing plant, and the packing is configured to adapt to the shape of the blade, so it can be used for blades of different shapes and sizes. The clamping walls, in fact, mold to the shape of the blade, which makes the packing extremely versatile. Moreover, when fully or partly deflated, the annular structures can be placed relatively easily about the blade, and then inflated to fix them to the blade. 
     The packing in general may comprise one or a number of variously combined inflatable annular structures  13 ,  29 ,  35 . 
     In another embodiment (not shown), inflatable annular structures  13 ,  29 ,  35  are relatively long, so that one inflatable annular structure  13 ,  29 ,  35  is enough to support blade  2 . 
     Using a plurality of inflatable annular structures, it is possible to cover the whole length of the blade. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art, for example, to the shape of the inflatable annular structures or to the means of connecting them. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.