TECHNICAL FIELD

The present invention relates to a wind power turbine for producing electric energy.

More specifically, the present invention relates to a wind power turbine comprising an electric rotating machine having a stator and a rotor, which comprises a supporting body mounted to rotate with respect to the stator about an axis of rotation; and a plurality of rotor segments, each designed to slide axially on and off the rotor supporting body when assembling and disassembling the rotor.

BACKGROUND ART

An electric rotating machine of the above type is known from WO 2006/032969, and has the advantage of enabling easy extraction and insertion of the rotor segments for maintenance .

Known methods of locking the rotor segments to the supporting body, however, are not altogether satisfactory.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a wind power turbine equipped with an electric rotating machine designed to lock the rotor segments easily to the supporting body.

According to the present invention, there is provided a wind power turbine for producing electric energy, the wind power turbine comprising an electric rotating machine having a stator and a rotor, which comprises a supporting body mounted to rotate with respect to the stator about an axis of rotation, and having a plurality of guides parallel to the axis of rotation; a plurality of rotor segments, each designed to slide, in an axial direction parallel to the axis of rotation, into a guide on the supporting body; and a plurality of expansion plugs, each designed to be positioned contacting one of the rotor segments to selectively lock the rotor segment in a given axial position inside the guide.

With one expansion plug, a rotor segment can thus be locked in a given position to the supporting body, and its position along the guide adjusted accurately.

Each expansion plug preferably extends parallel to the axis of rotation, and is substantially the same length as the rotor segments .

This enables the tightening force to be distributed along the whole length of the guide and the rotor segment, to prevent stress concentrating at given points between the segment and the supporting body.

In a preferred embodiment of the present invention, each expansion plug comprises a main body made of polymer material and extending along a longitudinal axis parallel to the axis of rotation.

Despite its length, the expansion plug according to the present invention is extremely lightweight and easy to handle .

Structurally, the main body of the expansion plug preferably comprises a central portion parallel to the longitudinal axis; and two side portions parallel to the longitudinal axis, located on opposite sides of the central portion, and connected to the central portion in elastically deformable manner.

The main body preferably comprises a plurality of parallel arms arranged in a herringbone pattern and extending between the central portion and the side portions .

By virtue of the arms, relative axial movement between the central portion and the side portions produces a corresponding tangential movement of the side portions with respect to the central portion.

In a preferred embodiment of the present invention, the expansion plug comprises an actuator for moving the central portion with respect to the side portions in the axial direction and so moving the side portions in the tangential direction perpendicular to the axial direction. In the present invention, one actuator conveniently deforms the expansion plug along its whole length, and is preferably located at one end of the expansion plug.

The actuator preferably comprises a threaded rod aligned and integral with the central portion; a bracket having a hole engaged by the threaded rod, and two opposite supporting ends which rest on the ends of the side portions; and a nut, which engages the threaded rod to press the bracket and simultaneously push the side portions and pull the central portion.

The expansion plug may advantageously be locked and released using one nut.

In a preferred embodiment of the present invention, the supporting body comprises a plurality of radial ribs; each guide extending between a pair of facing ribs, and defining a seat for housing a rotor segment and an expansion plug.

The ribs and the supporting body may be formed in one piece, or the ribs may be fixed to the supporting body .

The guide and the rotor segment are preferably designed to form a prismatic joint, which only allows the rotor segment to slide inside the guide in an axial direction with respect to the supporting body.

As such, the guide actually prevents tangential and radial movement of the rotor segment, and the expansion plug simply prevents axial movement of the rotor segment with respect to the supporting body.

This function of the expansion plug is preferably achieved by positioning the expansion plug between two ribs and between the supporting body and the rotor segment, so as to push the rotor segment against the two ribs and lock the rotor segment inside the guide.

The expansion plug and the supporting body, i.e. the ribs, are preferably designed to form two wedge joints, so that expansion of the expansion plug in the tangential direction produces thrust in the radial direction to lock the rotor segment against the ribs.

In other words, the supporting body and the expansion plug cooperate to direct the action of the expansion plug radially.

In a preferred embodiment of the present invention, each rotor segment is elastically expandable and controllable by the expansion plug.

In another preferred embodiment of the present invention, each guide is defined by a pair of grooves parallel to the axis of rotation and formed in the supporting body; each rotor segment comprising an active part, and two wings having two first ends, which slide into the guide to form, with the grooves, a prismatic joint slidable in the axial direction; the expansion plug being designed to exert a tangential parting force on the first ends of the wings, to lock the rotor segment inside the supporting body.

The supporting body may thus be very simple in design, e.g. defined by a cylindrical wall with axial grooves, and the expansion plug simply parts the wings slightly to lock the rotor segment frictionally inside the grooves.

The two wings of the rotor segment are preferably connected to each other near the middle to form a gripper, and comprise two second ends opposite the first ends and designed to grip the active part when the first ends are parted.

Structurally, the wings are separate from the active part of the rotor segment, but locking the wings to the supporting body advantageously locks the wings simultaneously to the active part.

A further object of the present invention is to provide a wind power turbine electric rotating machine rotor designed to eliminate the drawbacks of the known art .

According to the present invention, there is provided an electric rotating machine rotor for a wind power turbine for producing electric energy, the rotor comprising a supporting body mounted to rotate about an axis of rotation and having a plurality of guides parallel to the axis of rotation; a plurality of rotor segments, each designed to slide, in an axial direction parallel to the axis of rotation, into a guide on the supporting body; and a plurality of expansion plugs, each positioned contacting one of the rotor segments and designed to change size in controlled manner to selectively lock the rotor segment in a given axial position inside the guide.

BRIEF DESCRIPTION OF THE DRAWINGS

A number of non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a side view, with parts removed for clarity, of a wind power turbine in accordance with the present invention;

Figure 2 shows a larger- scale , partly sectioned side view, with parts removed for clarity, of a detail of the Figure 1 wind power turbine;

Figure 3 shows a larger- scale section, with parts removed for clarity, of a detail in Figure 2;

Figure 4 shows a view in perspective, with parts removed for clarity, of a detail in Figure 3;

Figure 5 shows a larger-scale section, with parts removed for clarity, of a detail in Figure 3 ;

Figure 6 shows a section, with parts removed for clarity, of a rotor portion in accordance with an alternative embodiment of the present invention; Figure 7 shows a plan, view, with parts removed for clarity, of a component of the wind power turbine in accordance with a variation of the present invention;

Figure 8 shows a larger- scale plan view, with parts removed for clarity, of a detail in Figure 7;

Figure 9 shows a larger-scale section, with parts removed for clarity, of the Figure 7 component along line IX- IX.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole a wind power turbine for producing electric energy, and which comprises a vertical support 2; a nacelle 3 fitted to vertical support 2 to rotate about an axis of rotation A2 ; an electric rotating machine 4; and a rotating assembly 5 fitted to nacelle 3 to rotate about an axis of rotation Al .

Nacelle 3 is substantially a tubular member supporting rotating assembly 5, which extends partly inside and partly outside nacelle 3, which, in the example shown, comprises a curved tubular member 6 and part of electric rotating machine 4.

As shown in Figure 2, electric rotating machine 4 is tubular, and comprises a stator 7 and a rotor 8. Stator 7 comprises a cylindrical wall 9, and stator segments 10 arranged about axis of rotation Al and fixed to the inner face of cylindrical wall 9; and rotor 8 comprises a supporting body 11, and rotor segments 12 arranged about axis of rotation Al and fixed to the outside of supporting body 11.

More specifically, nacelle 3 comprises curved tubular member 6 and stator 7, or rather cylindrical wall 9 of stator 7.

Cylindrical wall 9 has two opposite ends, one of which is fixed to curved tubular member 6.

Rotating assembly 5 comprises rotor 8; a hub 13; and blades 14 fitted to hub 13.

Rotor 8 of electric rotating machine 4 comprises a plurality of guides 15; and a plurality of expansion plugs 16, each for locking one of rotor segments 12 to supporting body 11 in a given axial position inside one of guides 15. More specifically, each expansion plug 16 is associated with a respective rotor segment 12 to lock it in a given position with respect to supporting body 11.

Each expansion plug 16 extends along a longitudinal axis B parallel to axis of rotation Al, and is preferably substantially the same length as rotor segments 12 and guides 15.

As shown in Figure 5, each expansion plug 16 comprises a main body 17 made of polymer material and comprising a central portion 18 parallel to longitudinal axis B, and two side portions 19 parallel to longitudinal axis B, located on opposite sides of central portion 18, and connected to central portion 18 in elastically deformable manner. Main body 17 has a shallow cross section, as shown more clearly in Figures 3 and 4, and the connection of central portion 18 to side portions 19 comprises a plurality of parallel arms 20 arranged in a herringbone pattern and extending between central portion 18 and side portions 19. This design of expansion plug 16 allows relative movement between side portions 19 and central portion 18 in an axial direction Dl . In fact, central portion 18, each side portion 19, and two arms 20 connecting central portion 18 to side portion 19 behave in the same way as an articulated quadrilateral, i.e. relative movement between central portion 18 and side portions 19 in axial direction Dl moves side portions 19 with respect to central portion 18 in a tangential direction D2 , so side portions 19 remain parallel to longitudinal axis B. In other words, deformation of main body 17 consists in a variation in the width of main body 17.

The height of main body 17 remains substantially unchanged .

Relative movement between central portion 18 and side portions 19 alters the length of main body 17.

Expansion plug 16 comprises an actuator 21 for selectively expanding and contracting main body 17. In other words, expansion plug 16 is selectively- expandable in controlled manner.

Actuator 21 is located at one end of expansion plug 16 for easy user access.

Actuator 21 is preferably operated manually, possibly using a tool such as a wrench.

Actuator 21 is fitted to main body 17 and designed to produce a controlled variation in the size of main body 17 in at least one direction, which, in the example shown, is tangential direction D2.

Actuator 21 comprises an actuating mechanism for elastically deforming main body 17 in tangential direction D2 when expansion plug 16 is fitted to supporting body 11.

More specifically, actuator 21 is designed to move central portion 18 with respect to side portions 19 in axial direction Dl, and structurally comprises a threaded rod 22 aligned with central portion 18 and integral with main body 17; a bracket 23 having a hole 24 engaged by threaded rod 22, and two opposite supporting ends 25 which rest on the ends of side portions 19; and a nut 26 which engages threaded rod 22 to press bracket 23 and simultaneously push side portions 19 and pull central portion 18. As nut 26 is screwed on threaded rod 22, central portion 18 is pulled towards bracket 23, which pushes side portions 19 to move central portion 18 slightly with respect to side portions 19 in axial direction Dl . At the same time, actuator 21, i.e. the relative movement produced by it, moves arms 20 into a position substantially perpendicular to longitudinal axis B, thus expanding plug 16 in tangential direction D2.

As shown in Figure 3, supporting body 11 comprises a plurality of radial ribs 27 parallel to axial direction Dl, i.e. to axis of rotation Al, and equally spaced about axis of rotation Al (Figure 2) . Each guide 15 is defined by two facing ribs 27, and itself defines a seat for housing a rotor segment 12 and an expansion plug 16. Each guide 15 and each rotor segment 12 define a prismatic joint slidable in direction Dl . For which purpose, each rib 27 has a contoured profile substantially complementary with the contoured profile of rotor segment 12, and cooperates with rotor segment 12 to retain it in a radial direction D3.

As shown in Figure 4, each rotor segment 12 is substantially defined by an active body comprising two superimposed rows of permanent magnets 28; two magnetic guides 29 made of laminations and located on opposite sides of the rows of permanent magnets 28; and a cover 30. When inserted inside respective guide 15, rotor segment 12 defines a seat for expansion plug 16. More specifically, expansion plug 16 is located between two ribs 27, and between supporting body 11 and rotor segment 12 to exert thrust on rotor segment 12 in radial direction D3 and lock rotor segment 12 frictionally inside guide 15.

As shown in Figure 3, expansion plug 16 and supporting body 11 define two wedge joints, so that expansion of plug 16 in tangential direction D2 produces thrust in radial direction D3 to lock rotor segment 12. Side portions 19 are wedged between supporting body 11 and rotor segment 12. More specifically, supporting body 11 has two inclined faces 31 on which side portions 19 slide. Supporting body 11, expansion plug 16 and rotor segment 12 thus define a reversible locking system by which to selectively lock and release rotor segment 12.

In the Figure 6 embodiment, rotor 8 comprises a supporting body 32; a plurality of rotor segments 33 which slide onto supporting body 32 in axial direction Dl; and a plurality of expansion plugs 34 for locking rotor segments 33 to supporting body 32. Supporting body 32 is in the form of a cylindrical wall, and has a plurality of guides 35, each defined by two grooves 36 parallel to axial direction Dl and diverging inwards in radial direction D3.

Each rotor segment 33 comprises two wings 37, the two ends 38 of which slide inside guide 35, i.e. inside respective grooves 36; ends 38 and grooves 36 form a prismatic joint slidable in axial direction Dl; and expansion plug 34 is located between the two wings 37 and designed to exert a parting force on ends 38 of wings 37 in tangential direction D2 to lock rotor segment 33 inside supporting body 32. In this case, too, supporting body 32, rotor segment 33 and expansion plug 34 define a reversible locking system.

Expansion plug 34 is structurally similar to expansion plug 16, except that it is not designed to operate as a wedge .

Each rotor segment 33 differs from rotor segment 12 by comprising two wings 37 for retaining the active part of rotor segment 33 where the active part corresponds substantially to the whole of rotor segment 12.

The wings 37 in each pair are preferably connected near the middle to form a gripper, and have respective ends 39 opposite ends 38 and for gripping the active part of rotor segment 33. In other words, ends 39 and the active part form a prismatic joint slidable in axial direction Dl, and parting ends 38 also grips ends 39 onto the active part of rotor segment 33. The active part of rotor segment 33 is also locked between wings 37 by friction.

Figures 7 to 9 show an expansion plug 40 geometrically and functionally similar to expansion plug 16, and the component parts of which corresponding to those of expansion plug 16 are indicated using the same reference numbers as for expansion plug 16. Expansion plug 40 comprises a main body 17 made partly of polymer material and partly of metal, and which comprises a central portion 18 parallel to longitudinal axis B, and two side portions 19 parallel to longitudinal axis B, located on opposite sides of central portion 18, and connected to central portion 18 in elastically deformable manner. More specifically, central portion 18 is reinforced with a bar 41 embedded in the polymer material along substantially the whole length of main body 17, and which projects from one end of main body 17 to form threaded rod 22, is preferably made of steel, and is preferably threaded completely, so the polymer material adheres firmly to it.

Side portions 19 are reinforced with respective section bars 42 designed to contact parts of rotor 8 (as shown in Figure 3) . Section bars 42 preferably extend the whole length of main body 17, and each have a C- shaped cross section (as shown in Figure 9) to form a groove filled with polymer material.

Each section bar 42 is preferably made of aluminium .

The connection of central portion 18 to side portions 19 comprises a plurality of parallel arms 20 arranged in a herringbone pattern and extending between central portion 18 and side portions 19. This design of expansion plug 40 makes central portion 18 and side portions 19 extremely rigid, so highly deformable polymer material can be used; and section bars 42 improve the abrasion resistance of expansion plug 40.

A variation of expansion plug 34 in Figure 6 may obviously also comprise a bar 41 and section bars 42 like expansion plug 40 in Figures 7 to 9.

Clearly, changes may be made to the wind power turbine as described herein without, however, departing from the scope of the accompanying Claims . In particular, the present invention also relates to wind power turbines equipped with electric rotating machines with a non-tubular structure, or in which the rotor extends about the stator. Moreover, though particularly suitable for wind power turbines with large electric rotating machines, the reversible locking system described can also be used on rotors of large electric rotating machines employed in other technical fields.