|Title of Invention||
WIND ENERGY UNIT COMPRISING A HOLLOW SHAFT FOR ROTOR HUB AND GENERATOR
|Abstract||The invention relates to a wind energy unit, with a (hollow) axle sleeve (20) and a hollow shaft (11) for the rotor mounted thereon. A single bearing (15) which also takes up torque is all that is provided between the axle sleeve and the hollow shaft, thus rendering a significant reduction in the weight of the machine components to be fixed to the machine support (4) and thus to the top of the tower, without affecting the necessary arrangement between the turning and stationary components of the electrical generator. The turning generator components (10) run essentially radially in relation to the bearing. A double-row taper roller bearing, with roller series arranged at 45° to each other is particularly used as bearing.|
Argestrasse 19, 26607 Aurich
Wind power installation having a hollow shaft for rotor hub and generator
The invention concerns a wind power installation comprising a machine carrier which is to be fixed to the top of a pylon and which on the one hand holds the static part of an electrical generator and on the other hand supports the rotating part thereof as well as a hub of a rotor which carries rotor blades, wherein the rotor hub and the rotating part of the generator are fixed to a common hollow shaft which is supported by means of a single bearing which also carries moments on an axis tube member which is mounted to the machine carrier.
DD 261 395 Al discloses a wind power installation in which both the axis tube member and also the hollow shaft comprises two cylindrical portions which are spaced in the axial direction and which are of greatly different diameters and which are respectively connected together by a conical portion. Both cylindrical parts of the axis tube member and the hollow shaft are connected together by a respective rolling bearing, more specifically the cylindrical portion of larger diameter by an inclined roller bearing near the machine carrier and the cylindrical portion of smaller diameter at a considerable spacing therefrom on the other side of the fixing/mounting of the rotor blades on the rotor hub.
A bearing arrangement with a single bearing is known from DE 44 02 184 Al. In that case a single groove-type ball bearing is arranged at the common centre of mass of the rotatable part of the generator and of the rotor. That arrangement admittedly provides that the single bearing does not have to carry any moments and can therefore run with a comparatively low level of wear, but that arrangement suffers from the disadvantage that air gap guidance and control in the generator is not exact and therefore a
larger air gap has to be set. That reduces the level of efficiency of the generator.
It is this that the invention seeks to remedy. In tne arrangement and configuration outlined in the opening part of this specification, the invention provides that the rotating part of the generator is radially substantially aligned with the bearing. In that way, not only are the axial length of the axis tube member and thus the weight thereof considerably reduced, but in addition the bearing can withstand all moments, even those which fluctuate in their direction, and which occur around axes extending transversely with respect to the axis of the shaft, without the relative position of the generator rotor with respect to the generator stator changing beyond a critical dimension - even in modern installations with a generator diameter of 4000 mm the generator gap may not exceed a width of 3 mm. Moreover, the moment loading on the bearing is reduced by virtue of the radial alignment of the rotating part of the generator with the bearing. In addition, the centrifugal forces which occur upon rotation of the generator rotor can be carried in a particularly problem-free manner by the bearing and operational reliability of the generator is enhanced.
It is admittedly known from AT 403 189 B for the rotor hub of a wind power installation to be fixed to a hollow shaft which is fixed with a single rolling bearing on the machine, housing. In that case however the hollow shaft is keyed to a shaft coupled to a generator which is arranged on the opposite side of the pylon and which is therefore axially remote. The problems which form the underlying basis of the invention therefore do not occur in that case. A similar consideration applies in regard to earlier but not previously published FR 2 810 374 Al in which there is provided a generator having radial gaps and the rotating parts of the generator are not aligned in their entirety with the single rolling bearing.
Preferably the bearing is a twin-row inclined roller bearing with rows of rollers which are arranged in mutually angular relationship. In that case it is particularly provided that each row of rollers includes an angle of about 45° with the axis of the axis tube member and the hollow shaft. That provides for an optimum in terms of the bearing carrying moments. The
bearing is desirably arranged next to the machine carrier, wherein the axial length of the axis tube member is substantially restricted to the length of the bearing. The size and the weight of the elements of the wind power installation, which are to be mounted at the top of the pylon, are substantially reduced in that way.
The drawing illustrates the invention in an embodiment thereof. In the drawing:
Figure 1 is a partly diagrammatic view in longitudinal section through a wind power installation at the top of the pylon carrying it, and
Figure 2 is an enlarged view of a portion of the bearing in Figure 1 (portion A).
The housing 3 of a machine carrier which is generally identified by reference 4 is fixed at the upper end (top 2) of a pylon 1 in the usual manner. Fixed to the front end of the housing is the central ring 5 of a star-shaped carrier 6 for the stator 8 of an electrical generator which is generally identified by reference numeral 7; its rotor or armature 9 is arranged in concentric relationship therewith with a narrow gap.
The rotor 9 of the generator 7 is held by a carrier 10 which is also substantially star-shaped and which is fixed to a hollow shaft 11 to which the hub 12 of the rotor with the rotor blades 13 is flange-mounted in coaxial relationship.
Jointly with a cover flange 14 the hollow shaft 11 - which is of a suitably cranked configuration - encloses the outer race 15 of an inclined roller bearing having two rows of rollers 17 which are arranged inclined at an angle of 45° relative to the axis 16 (and thus at an angle of 90° relative to each other). The inner race of the bearing is formed by the rings 18 which each support a respective row of rollers 17 and which are held by an annular collar 19 of an axis tube member 20 which in turn is flange-mounted to the central ring 5 and thereby fixed to the machine housing 3. The axial length of the axis tube member 20 only slightly exceeds the width of the inclined roller bearing consisting of the races 15, 18 and the rows of rollers 17.
1. A wind power installation comprising a machine carrier (4) which is to be fixed to the top of a pylon (1) and which on the one hand holds the static part (8) of an electrical generator (7) and on the other hand supports the rotating part (9) thereof as well as a hub (12) of a rotor which carries rotor blades (13), wherein the rotor hub (12) and the rotating part (9) of the generator are fixed to a common hollow shaft (11) which is supported by means of a single bearing (15, 17, 18) which also carries moments on an axis tube member (20) which is mounted to the machine carrier (4), characterised in that the rotating part (9) of the generator is radially substantially aligned with the bearing (15, 17, 18).
2. A wind power installation according to claim 1 characterised in that the bearing (15, 17, 18) is arranged next to the machine carrier (4) and the axial length of the axis tube member (11) is restricted substantially to the width of the bearing,
3. A wind power installation according to claim 1 or claim 2 characterised in that the bearing is a twin-row inclined roller bearing (15, 18) with rows of rollers (17) arranged in mutually angular relationship.
4. A wind power installation according to claim 3 characterised in that each row of rollers (17) includes an angle of about 45° with the axis (16) of the axis tube member (20) and the hollow shaft (11),
A wind power installation substantially as herein described with reference to the accompanying drawings.
|Indian Patent Application Number||1104/CHENP/2003|
|PG Journal Number||30/2009|
|Date of Filing||18-Jul-2003|
|Name of Patentee||SHRI. WOBBEN, Aloys|
|Applicant Address||Argestrasse 19, 26607 Aurich|
|PCT International Classification Number||F03D1/06|
|PCT International Application Number||PCT/EP2002/000307|
|PCT International Filing date||2002-01-15|