DE102004031329A1 - External rotor for a generator in a wind power installation has an outer ring (OR) and a grouping with a permanent magnet of components following each other at a tangent on the OR inner side - Google Patents

Abstract

An outer ring (23a) of a rotor (9a) remains under tension and holds a grouping of components together. Assigned to the inner side of this outer ring and attached to a support drum and stretched, the grouping has permanent magnets (33a). Afterwards, the support drum is removed. An independent claim is also included for a method for producing a rotor for a wind power generator.

Description

The The invention relates to an external rotor of a Generator, in particular a generator of a wind turbine, according to claim 1 and a method for producing such an external rotor according to claim 23rd

The multi-pole external rotor of generators gearless wind turbines, such as those from the DE 102 39 366 A1 are known, have a relatively large diameter. To produce such external rotor with the required dimensional accuracy, in particular the inner diameter, requires a high manufacturing cost.

Of the Invention is based on the object, an external rotor of a generator, in particular a generator a wind turbine, with an outer ring and a permanent magnet to provide occupying coverage on the inside of the outer ring, which is can be produced accurately with reduced production costs.

Of the solving this task External rotor after the invention is characterized in that the outer ring is under tension and the occupancy has tangentially abutting components, which the outer ring in the manner of a vault holds together.

Advantageous let yourself such a generator rotor in that the permanent magnets having, on the Inside of the outer ring of the runner Assigned assignment applied to a support drum, on the applied on the support drum Occupancy of the outer ring cocked and the support drum is then removed, after which the tensioned outer ring occupancy in the Type of vault holds together.

Advantageous serves the support drum when building the runner as a gauge, so that the inner diameter is very accurate and reproducible can be complied with.

There it far less on manufacturing tolerances of the outside diameter arrives, the outer ring can in the preferred embodiment the invention by a winding of a flexible strand material be formed. This may be fabric tape or rope strands.

Preferably the winding is under exercise a tensile force on the strand material on the through the drum supported Occupancy applied.

Preferably the strand material is formed by fibers, in particular glass fibers.

A Winding of such a strand material can be with a shrinkage curable Soak plastic material, so for a high tension of the outer ring is taken care of.

To the Remove the support drum its diameter is reduced, e.g. this can be done that the support drum is formed as an open ring with a wedge in the ring opening and the wedge, to reduce the diameter, removed from the ring opening becomes.

Of the External rotor manufactured in the manner described has one for transport and the mounting sufficient inherent stability. In the installed state is the runner appropriate to his two End faces reinforced by stabilizing rings, which preferably with the assignment connected, in particular screwed, are. Through this Connection is one for the generator operation sufficient Beulsteifigkeit the rotor ring secured.

In Another embodiment of the invention is the occupancy against the Generator air gap covered by an inner ring in which it is e.g. one on the support drum wound plastic skin acts. Both the inner ring and the outer ring can be glued to the assignment. Likewise, the tension through the voltage of the outer ring held together components of the assignment also glued together be.

In Another embodiment of the invention are between the assignment and the outer ring axially extending cooling channels for the flow with cooling air intended.

Preferably has the assignment next to the permanent magnets, the permanent magnets holding elements of magnetically conductive material, preferably Iron, up. These holding elements can be formed by profile pieces its length is equal to the axial width of the assignment.

Preferably is the occupancy over these profile pieces connected to the stabilizing rings, wherein the profile pieces frontally abut against the rings and with the rings e.g. are bolted.

The profile pieces may have a shape such that their arrangement in the occupancy troughs are formed, which covers the outer ring to form the cooling channels. The profile pieces can, for example, in cross-section a triangular or U-shape.

In an embodiment The invention comprises the assignment in the circumferential direction alternately permanent magnets and holding elements as arranged between the permanent magnets Spacers. In an alternative embodiment has the assignment in the circumferential direction abutting holding elements on, on their side facing the air gap with the permanent magnet connected, preferably glued, are.

In a further embodiment The invention is between two permanent magnets separating profile pieces respectively a spacer arranged from a magnetically non-conductive material.

In Further embodiment of the invention, the profile pieces have recesses on, through which in each case a passage from the adjacent cooling channel is formed to the air gap of the generator. Accordingly, in provided openings aligned with the inner ring to the recesses. The passageways can too Passage slots in the stator pack be aligned so that emerging from the rotor cooling currents immediately in the stand can reach.

The Invention will now be described with reference to exemplary embodiments and the enclosed, to these embodiments related drawings closer explained become. Show it:

1 a tower head of a gearless wind turbine with a generator according to the prior art,

2 a partial view of a tower head with a generator having an external rotor according to the invention,

3 various design options of in 2 shown external rotor,

4 a diagram illustrating the magnetic flux in a generator with an external rotor according to the invention,

5 a partial view of another embodiment of an external rotor according to the invention,

6 and 7 Arrangements of permanent magnets and holding profiles used on an external rotor according to the invention

8th an illustration explaining the arrangement of permanent magnets and holding profiles relative to a rotor stabilizing ring,

9 An embodiment of a rotor according to the invention with an oblique arrangement of permanent magnets and retaining profiles, and

10 a usable for producing an external rotor according to the invention support drum.

It is first pointed to the one tower head with a generator of the prior art 1 Referenced where indicated by the reference numeral 1' one on a tower 2 around an axis 3 rotatably mounted support structure of the tower head is designated. On the support structure 1' is about a storage 4 ' one around an axis 5 rotatable rotor 6 ' with rotor blades 7 ' appropriate. A the storage 4 ' surrounding multi-pole generator has a stand 8th' and a rotor fitted with permanent magnets 9 ' on. The runner 9 ' is over an annular disk 10 ' directly with the rotor 6 ' connected. The reference number 11 indicates an outer casing of the tower head.

An in 2 shown in partial view tower head has a generator with a rotor 9 on, which has a flange 12 with one of the annular disc 10 ' from 1 corresponding annular disc 10 connected is. The flange 12 opposite in the axial direction is the rotor 9 with a flange 13 screwed, which in conjunction with an annular disc 14 stands, on the inner edge if necessary, a braking device 15 attacks. The flanges 12 and 13 make up the runner 9 stabilizing disc-shaped rings.

A rotor 6 with rotor blades 7 is about a single moment bearing comprehensive storage 4 on the supporting structure 1 appropriate.

One inside the runner 9 arranged stand 8th has a laminated core 16 and windings 17 on. The laminated core 16 is of radial, cooling channels forming slots 18 interspersed, the generator air gap 31 and an interior 19 open. The interior 19 is between the stands 8th carrying, with the support structure 1 connected annular flanges 20 and 21 formed and stands over openings 22 , which are around the circumference of the supporting structure 1 are distributed, with the interior of the support structure 1 in connection.

The runner 9 has an outer ring 23 and one on the inside of the outer ring 23 arranged, permanent magnets comprehensive assignment 24 on. In the occupancy 24 are to the slots 18 in the laminated core 16 aligned passageways 25 formed, which at one end to the air gap 31 of the generator and at the other end to channels 26 open. The axially passing through the runner, on the Circumference of the runner distributed channels 26 are between occupancy 24 and the outer ring 23 formed, as explained in more detail below.

As with arrows 27 is indicated, the generator is penetrated by a flow of cooling air through which openings 28 and 29 in the flanges 12 and 13 into the channels 26 enters, through the passageways 25 into the generator air gap 31 and from there through the slots 18 in the laminated core in the interior 19 and then through the openings 22 through into the interior of the support structure 1 and finally flows through a heat exchanger, not shown.

It will be up now 3 Reference where possible structures of the runner 9 are shown partially seen in the axial direction of view. As 3 shows, the laminated core 16 of the stand 8th groove 30 for the windings 17 on. One of the grooves shown 30 is in 3c exemplarily filled with winding wires.

As 3 furthermore, the runner points 9 on his the generator air gap 31 facing inside an inner ring 32 on, which forms a cover which protects the underlying parts of the rotor from corrosion and possibly contributes to the stabilization of the rotor.

The between the inner ring 32 and the outer ring 23 arranged occupancy 24 comprises distributed over the circumference of the rotor stack of three each, tangentially magnetized permanent magnet 33 wherein north and south poles face each other in the circumferential direction of successive permanent magnet stacks.

According to 3a are between the permanent magnet stacks of permanent magnets 33 acting as spacers holding profiles 34 arranged, which consist of a magnetically conductive material, preferably iron. The holding profiles 34 extend over the entire axial width of the rotor 9 and have tapped holes on machined end faces 35 for connection to the flanges 12 and 13 on. The holding profiles steer, like 4 explains the tangential flux of the permanent magnets by 90 °.

The holding profiles 34 have a U-shaped cross-section. The outer ring 23 covers the troughs formed by the U-shaped cross section, whereby the cooling channels 26 are formed.

In the embodiment of 3b are between stack arrangements of three permanent magnets 33 ' two each in cross-section triangular holding profiles 36 made of magnetically conductive material. Between the two holding profiles 36 is in each case an intermediate piece 37 arranged of magnetically non-conductive material.

A holding profile 36 is separate in 6 shown. The figure shows that the retaining profiles edge recesses 40 to form the passages 25 exhibit. While the profiles 36 extend over the entire axial width of the rotor, over the axial width of the rotor several permanent magnets 33 ' arranged and between the permanent magnets 33 ' to the marginal recesses 40 aligned gaps 43 educated.

8th shows the arrangement of the holding profiles 36 and the magnets arranged between the holding profiles 33 ' with respect to the openings 29 in the flange 13 , These openings 29 are to the channels 26 ' aligned, which are formed by that two consecutive triangular retaining profiles 36 form a hollow.

In the embodiment of 3c are instead of three radially stacked permanent magnets 33 four permanent magnets 33 '' intended. Two, each arranged between permanent magnet stacks, by a magnetically non-conductive intermediate piece 39 separate holding profiles 38 made of magnetically highly conductive material have the shape of an unequal triangle in cross section. One of the in 3c shown holding profiles 38 is shown cut so that a marginal cutout 40 ' is visible, which together with one in the inner ring 32 opening formed at the site concerned 41 one of the passages 25 forms the generator air gap.

The intermediate pieces 37 and 39 , which have a slight wedge shape, can advantageously compensate tolerances of the permanent magnets and retaining profiles in the circumferential direction.

In 4 is indicated that the magnetic flux density in the air gap with respect to the remanence of the permanent magnets can be varied by changing the ratio of the triangle side lengths b and h. Since the lines of the magnetic flux are closed, their number in the radial direction through the air gap must be equal to the number in the tangential direction through the permanent magnets. If the height h of the magnetic column is greater than the width b in the air gap, the concentration of flux in the air gap occurs.

In the following figures are the same or equivalent parts with the same reference number as in the previous figures, the relevant reference number is in each case the letter a or b enclosed is.

In the embodiment of 5 are retaining profiles 42 made of highly conductive magnetic material, eg iron, provided with a triangular cross-section, wherein at one of the generator air gap 31a facing triangle side radially magnetized permanent magnets 33a are attached, each forming in groups of three half a north pole and a half south pole. The magnets 33a are with the in 7 separately shown holding profile 42 glued together. The holding profiles 42 deflect the magnetic flux by 180 °, which advantageously has no tendency to pass through the outer ring. The outer ring can therefore consist of both magnetically conductive and non-conductive material and be formed for example by a steel cylinder.

How out 9 shows, the faces of the holding profiles 34 . 38 and 42 be inclined to the longitudinal direction of the profiles, so that advantageously with the assembly of self-holding moments counteracting setting S results. 9 shows the holding profiles 36 corresponding holding profiles 36b whose end faces are at an angle α to the longitudinal direction of the holding profiles. About the end faces are the holding profiles with the flanges 12 and 13 corresponding flanges 12b and 13b screwed.

It will be up now 10 Reference is made to where a tool for making a in the 1 to 9 described rotor is shown.

The tool is a circular support drum 46 with an outer surface 44 , In the manufacture of the rotor described above, first, the inner ring 32 on the outside surface 44 applied. This may be a relatively thin skin of a plastic material. On the inner ring 32 becomes the occupation consisting of permanent magnets, holding profiles and possibly spacers 24 applied. The support drum is expediently made of a magnetizable material, so that the permanent magnets by magnetic force on the outer circumference of the inner ring 32 and the holding profiles are held by the permanent magnets. Alternatively or additionally, a bonding of the permanent magnets, holding profiles and spacers with the inner ring 32 and possibly with each other.

On the occupancy 24 becomes the outer ring 23 strained by using a flexible strand material, such as a band of glass fiber fabric, on the assignment 24 as outer ring a winding is applied. During winding, the strand material is under tension. Finally, the outer ring 23 impregnated with a shrinkable curable plastic material. The strand material may also have a wire or rope structure.

Of the shrinking outer ring device additionally under Tension and stops the tangentially abutting ones Components of occupancy in the manner of a vault by compressive stress in tangential direction together. The components, ie the permanent magnets, Holding profiles and possibly spacers become tangential and in addition radially compressed and thus form a relatively stable rotor ring.

The inner diameter of the runner 9 corresponds exactly to the diameter of the support drum 46 , The manufacturing tolerances of the outer diameter may be greater, as they affect the function of the generator less than that of the inner diameter.

After complete curing of the winding soaking plastic and possibly between the components adhesive is the finished runner 9 from the support drum 46 taken, what a wedge 45 is removed to reduce the diameter of the support drum and the outer surface 44 from the inner surface of the inner ring 32 to solve. Due to the clamping effect of the outer ring 23 and possibly bonding the occupancy components with each other and with the inner ring 32 the runner has a sufficient for transport and mounting stability. After assembly is through the stabilizing flanges 12 and 13 secured the required for the generator operation Beulsteifigkeit the runner.

Before the tension can also stabilizing rings in the form of flanges 12 and 13 be attached, which then during transport to the rotor ring 9 remain. However, at least the flange is required for installation of the stand 13 to lose weight beforehand.

extraordinarily is advantageous by the triangular in cross-section and U-shaped retaining profiles, by which hollows are formed, significantly saving weight and at the same time Cooling channels created.

Claims (27)

External rotor of a generator, in particular a generator of a wind turbine, with an outer ring ( 23 ) and a permanent magnet ( 33 ) ( 24 ) on the inside of the outer ring ( 23 ), characterized in that the outer ring ( 23 ) is live and the occupancy ( 24 ) tangentially abutting components ( 33 . 34 . 36 . 37 . 38 . 42 ), which holds the outer ring in the manner of a vault. External rotor according to claim 1, characterized in that the outer ring ( 23 ) a wick ment of a flexible strand material. External rotor after Claim 2, characterized in that the strand material Fibers, preferably glass fibers, is formed. External rotor according to one of claims 1 to 3, characterized in that the outer ring ( 23 ) has a shrink-cured plastic material. External rotor after one of the claims 2 to 4, characterized in that the winding in the plastic material is embedded. External rotor according to one of claims 1 to 5, characterized in that the rotor ( 9 ), in particular the occupancy ( 24 ), is connected at the two end faces each with a stabilizing ring. External rotor according to one of claims 1 to 6, characterized in that the occupancy ( 24 ) against the generator air gap ( 31 ) by an inner ring ( 32 ) is covered. External rotor according to one of claims 1 to 7, characterized in that between the assignment ( 24 ) and the outer ring ( 23 ) axially extending cooling channels ( 26 ) are formed. External rotor according to one of claims 1 to 8, characterized in that the occupancy ( 24 ) next to the permanent magnets ( 33 ) the permanent magnets ( 33 ) holding elements of magnetically conductive material. External rotor according to claim 9, characterized in that the holding elements by profile pieces ( 34 . 36 . 38 . 42 ) whose length is equal to the axial width of the occupancy ( 24 ). External rotor according to claim 9 or 10, characterized in that the profile pieces ( 34 . 36 . 42 ) frontally with the stabilizing rings ( 12 . 13 ), preferably bolted, are. External rotor according to one of claims 9 to 11, characterized in that the retaining elements ( 34 . 36 . 42 ) to form the channels ( 26 ) Forming depressions through the outer ring ( 23 ) are covered. External rotor according to one of claims 9 to 12, characterized in that the occupancy ( 24 ) in the circumferential direction alternately permanent magnets ( 33 ) and holding elements ( 34 . 36 . 38 ) than between the permanent magnets ( 33 ) arranged spacers. External rotor according to one of claims 9 to 13, characterized in that the occupancy ( 24a ) in the circumferential direction abutting holding elements ( 42 ), which are at their the air gap ( 31a ) facing side with the permanent magnets ( 33a ) are connected. External rotor according to one of claims 12 to 14, characterized in that the profile pieces ( 34 . 36 . 38 . 42 ) have a triangular or U-shape in cross-section. External rotor according to one of claims 1 to 15, characterized in that all the runners ( 9 ) forming components are glued together. External rotor according to one of claims 1 to 16, characterized in that the occupancy ( 24 ) between the retaining elements ( 36 ) to be arranged ( 37 . 39 ) of magnetically non-conductive material. External rotor according to one of claims 6 to 17, characterized in that one of the rings ( 12 . 13 ) with the rotor ( 6 ) of the wind turbine and the other ring with a serving as a brake and locking disc annular disc ( 14 ) connected is. External rotor after one of the claims 15 to 18, characterized, that the profile pieces in relation are arranged on the permanent magnets, that the magnetic Induction in the generator gap is greater as the remanence of the magnets, wherein the radial height of the profile pieces is greater as the tangential extent of the magnetic flux in the air gap. External rotor according to one of claims 10 to 19, characterized in that the end faces of the profile pieces ( 36b ) are inclined so that a desired setting (S) results in the assembly by itself. External rotor according to one of claims 10 to 20, characterized in that the retaining profiles recesses ( 40 ) to form radial passages between the channel and the generator gap. External rotor according to one of claims 9 to 21, characterized in that the rings ( 12 . 13 ) to the channels ( 26 ) aligned openings ( 29 . 30 ) exhibit. Method for producing a rotor according to one of Claims 1 to 22, characterized in that a permanent magnet ( 33 ), on the inside of an outer ring ( 23 ) of the runner ( 9 ) occupancy ( 24 ) on a support drum ( 46 ), on which the support drum ( 46 ) applied assignment of the outer ring ( 23 ) and the support drum ( 46 ) Will get removed. A method according to claim 23, characterized in that for the formation of the outer ring ( 23 ) on the occupancy ( 24 ) a flexible strand material, preferably by applying a tension on the strand material, is wound up. Method according to Claim 24, characterized that the winding of the strand material with a shrinking under curing material soaked becomes. Method according to one of claims 23 to 25, characterized in that for removing the support drum ( 46 ) the diameter of the support drum with detachment from the rotor ( 9 ) is reduced. Method according to one of claims 23 to 26, characterized in that before the clamping of the outer ring ( 23 ) the rings or flanges ( 12 . 13 ) with the applied occupancy ( 24 ) get connected.