FI20195396A1 - An electric machine element and an electric machine - Google Patents
An electric machine element and an electric machine Download PDFInfo
- Publication number
- FI20195396A1 FI20195396A1 FI20195396A FI20195396A FI20195396A1 FI 20195396 A1 FI20195396 A1 FI 20195396A1 FI 20195396 A FI20195396 A FI 20195396A FI 20195396 A FI20195396 A FI 20195396A FI 20195396 A1 FI20195396 A1 FI 20195396A1
- Authority
- FI
- Finland
- Prior art keywords
- electric machine
- machine element
- adjustable tensioning
- connection points
- tensioning arms
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/22—Rotating parts of the magnetic circuit
- H02K1/28—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/18—Structural association of electric generators with mechanical driving motors, e.g. with turbines
- H02K7/1807—Rotary generators
- H02K7/1823—Rotary generators structurally associated with turbines or similar engines
- H02K7/183—Rotary generators structurally associated with turbines or similar engines wherein the turbine is a wind turbine
- H02K7/1838—Generators mounted in a nacelle or similar structure of a horizontal axis wind turbine
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Energy (AREA)
- Sustainable Development (AREA)
- Motor Or Generator Frames (AREA)
Abstract
An electric machine element (100) comprises a core structure and adjustable tensioning arms (103, 104) each connected to two connection points (105, 106) of the electric machine element so that the two connection points are located a same distance away from a geometric axial center line (107) of the electric machine element. Each of the adjustable tensioning arms is provided with a tensioning device for directing mutually opposite forces to the connection points connected to the adjustable tensioning arm in order to adjust a shape of the core structure and thereby to adjust a shape of an airgap surface of the electric machine element.
Description
An electric machine element and an electric machine
The disclosure relates generally to electric machines. More particularly, the disclosure relates to an electric machine element that can be for example a part of a stator of an electric machine or a part of a rotor of an electric machine.
Furthermore, the disclosure relates to an electric machine.
In many electric machines such as e.g. directly driven wind generators, the number of pole pairs can be high and therefore a rotor yoke of an electric machine as well as a stator yoke of the electric machine are thin relative to an airgap radius of the electric machine. Therefore, there is often a need to provide an electric machine of the kind mentioned above with mechanical support structures for keeping a radial length of an airgap between a rotor and a stator within desired limits all over the airgap. For example, in an outer rotor permanent magnet machine, keeping a rotor shape can be critical for achieving the above-mentioned target related to the airgap.
Correspondingly, in an inner rotor electric machine, keeping a stator shape can be critical for achieving the above-mentioned target related to the airgap.
Publication EP2381560 describes an electric generator for a wind turbine. The o 20 electric generator comprises a tubular first support structure extending about an axis > of rotation and a tubular second support structure surrounded by the first support ro structure and extending about the axis of rotation. The second support structure is + substantially coaxial with the first support structure and rotatable with respect to the z first support structure. The electric generator comprises active stator parts attached c 25 — to the first support structure and active rotor parts attached to the second support 3 structure. The electric generator comprises a radial tensioning mechanism for = adjusting the shape of the first support structure. The radial tensioning mechanism
N comprises a stationary hub element and a plurality of radially directed adjustable tensioning arms extending radially from the hub element to the first support structure.
An inherent limitation related to the radial tensioning mechanism described in
EP2381560 is that the radial tensioning mechanism is not suitable for electric machines where a hub element or the like cannot be arranged for the radially directed adjustable tensioning arms. For example, it can be challenging to provide an outer rotor electric machine with a hub element needed by radially directed adjustable tensioning arms.
The following presents a simplified summary in order to provide a basic understanding of some aspects of various embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments.
In this document, the word “geometric” when used as a prefix means a geometric concept that is not necessarily a part of any physical object. The geometric concept can be for example a geometric point, a straight or curved geometric line, a geometric plane, a non-planar geometric surface, a geometric space, or any other geometric entity that is zero, one, two, or three dimensional.
In accordance with the invention, there is provided a new electric machine element for an electric machine. The electric machine element can be for example a rotor o element or a stator element for an electric machine. An electric machine element > according to the invention comprises: 3 - acore structure, and z - adjustable tensioning arms each connected to two of connection points of the c 25 electric machine element, the two connection points being located on a 3 geometric circle concentric with a geometric axial center line of the electric = machine element and thus the two connection points are located a same
N distance away from the geometric axial center line.
Each of the above-mentioned adjustable tensioning arms is provided with a tensioning device for directing mutually opposite forces to the connection points connected to the adjustable tensioning arm under consideration in order to adjust a shape of the core structure and thereby to adjust a shape of an airgap surface of the electric machine element.
As both connection points related to each adjustable tensioning arm are located a same distance away from the geometric axial center line of the electric machine element, there is no need for a hub element or the like to be connected to the adjustable tensioning arms. Thus, the above-described shape adjustment mechanism is usable also in cases where a hub element or the like cannot be used.
In accordance with the invention, there is provided also a new electric machine that comprises a first electric machine element and a second electric machine element rotatably supported with respect to each other, wherein the first electric machine element is an electric machine element according to the invention. The electric machine can be e.g. an outer rotor electric machine where the first electric machine element is a rotor element. It is however also possible that the electric machine is an inner rotor electric machine where the first electric machine element is a stator element.
Various exemplifying and non-limiting embodiments are described in accompanied dependent claims. o Various exemplifying and non-limiting embodiments both as to constructions and to > methods of operation, together with additional objects and advantages thereof, will ro be best understood from the following description of specific exemplifying and non- x limiting embodiments when read in conjunction with the accompanying drawings.
E 25 The verbs “to comprise” and “to include” are used in this document as open 2 limitations that neither exclude nor reguire the existence of unrecited features. The 3 features recited in dependent claims are mutually freely combinable unless
S otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.
Exemplifying and non-limiting embodiments and their advantages are explained in greater detail below in the sense of examples and with reference to the accompanying drawings, in which: figure 1 illustrates an electric machine element according to an exemplifying and non-limiting embodiment, figure 2 illustrates an electric machine element according to another exemplifying and non-limiting embodiment, and figure 3 illustrates an electric machine according to an exemplifying and non-limiting embodiment.
Description of the exemplifying and non-limiting embodiments
The specific examples provided in the description below should not be construed as limiting the scope and/or the applicability of the accompanied claims. Lists and groups of examples provided in the description are not exhaustive unless otherwise explicitly stated.
Figure 1 illustrates an electric machine element 100 according to an exemplifying and non-limiting embodiment. In this exemplifying case, the electric machine element 100 is a rotor element for a radial flux outer rotor permanent magnet machine. The electric machine element 100 comprises a core structure 101 that = 20 may comprise for example electrically insulated ferromagnetic sheets stacked in the
N axial direction of the electric machine element 100. In figure 1, the axial direction is = parallel with the z-axis of a coordinate system 199. In this exemplifying case, the > core structure 101 is a segmented core structure comprising circumferentially
E successive core segments. In figure 1, two of the core segments are denoted with 2 25 references 111 and 112. In this exemplifying case, the electric machine element 100
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O comprises surface-mounted permanent magnet elements attached to the core
O
N structure 101. In figure 1, one of the permanent magnet elements is denoted with a reference 114. The direction of magnetization is radial in each of the permanent magnet elements.
The electric machine element 100 comprises adjustable tensioning arms each connected to two connection points of the electric machine element 100. In figure 1, two of the adjustable tensioning arms are denoted with references 103 and 104 and the connection points connected to the adjustable tensioning arm 103 are denoted 5 with references 105 and 106. Both connection points related to each adjustable tensioning arm are located on a geometric circle that is concentric with a geometric axial center line 107 of the electric machine element 100. Therefore, both connection points related to each adjustable tensioning arm are located a same distance away from the geometric axial center line 107. Thus, each tensioning arm is secant positioned and there is no need for a hub element or the like to be connected to the adjustable tensioning arms. In figure 1, the above-mentioned geometric circle is presented with a dashed line. Each of the adjustable tensioning arms is provided with a tensioning device for directing mutually opposite forces to the connection points connected to the adjustable tensioning arm under consideration in order to adjust the shape of the core structure 101. Therefore, the shape of the airgap surface of the electric machine element 100 can be adjusted.
In the exemplifying electric machine element 100, all the connection points are located a same distance away from the geometric axial center line 107 and the adjustable tensioning arms are equally spaced so that the adjustable tensioning arms coincide with sides of a regular geometric octagon. In figure 1, the regular geometric octagon is presented with a dashed line. In an electric machine element according to an exemplifying and non-limiting embodiment, it is however also o possible that the connection points connected to one of adjustable tensioning arms
S are nearer to the geometric axial center line of the electric machine element than 3 25 the connection points connected to another one of the adjustable tensioning arms. s The exemplifying electric machine element 100 has eight adjustable tensioning
E arms. In an electric machine element according to an exemplifying and non-limiting
O embodiment, there can be e.g. three, four, five, six, seven, or more than eight
O adjustable tensioning arms.
N 30 The tensioning device of each adjustable tensioning arm can be for example a mechanical tensioning device, a hydraulic tensioning device, an electromechanical tensioning device, or a pneumatic tensioning device. A mechanical or electromechanical tensioning device may comprise for example a threaded rod and means for rotating an element having a corresponding threaded hole and the threaded rod with respect to each other. The adjustable tensioning arms can be operated prior to installation of stiffening components of the electric machine element 100, to ensure circular shape, and then securing the stiffening components.
The stiffening components are not shown in figure 1. In an electric machine element according to an exemplifying and non-limiting embodiment, the adjustable tensioning arms can be operated also during machine operation to correct the shape of the core structure. In a case of electromechanical tensioning devices, the electric — machine element may comprise e.g. slip-rings or a rotary transformer for supplying electricity to the electromechanical tensioning devices when the electric machine element is rotating.
The exemplifying electric machine element 100 illustrated in figure 1 comprises a housing element 108 that has a cylindrical wall so that the yoke section of the core — structure 101 is against the inner surface of the cylindrical wall. The housing element 108 comprises the connection points connected to the adjustable tensioning arms.
In an electric machine element according to an exemplifying and non-limiting embodiment, it is however also possible that the core structure is not a segmented core structure and the core structure is arranged to comprise the connection points for the adjustable tensioning arms. The housing element 108 comprises projections which protrude radially towards the geometric axial center line 107 of the electric machine element 100 and which constitute the connection points for the adjustable o tensioning arms. In figure 1, two of the projections are denoted with references 109
S and 110. Each of the adjustable tensioning arms is, in a radial direction, between 3 25 — the cylindrical wall of the housing element 108 and the geometric axial center line s 107, and the adjustable tensioning arms are axially a distance away from the core
E structure 101. In the view shown in figure 1, the adjustable tensioning arms are in
O front of the core structure 101. 0 > Figure 2 illustrates an electric machine element 200 according to an exemplifying
N 30 and non-limiting embodiment. In this exemplifying case, the electric machine element 200 is a stator element for a radial flux inner rotor electric machine. The electric machine can be e.g. a permanent magnet machine, an induction machine,
a slip ring machine, an electrically excited synchronous machine, or a synchronous reluctance machine. The electric machine element 200 comprises a core structure 201 that may comprise for example electrically insulated ferromagnetic sheets stacked in the axial direction of the electric machine element 200. In figure 2, the axial direction is parallel with the z-axis of a coordinate system 299. In this exemplifying case, the core structure 201 is a segmented core structure comprising circumferentially successive core segments. In figure 2, two of the core segments are denoted with references 211 and 212. The electric machine element 200 comprises windings whose coil sides are in slots of the core structure 201. In figure 2, one of the slots of the core structure 201 is denoted with a reference 214.
The electric machine element 200 comprises adjustable tensioning arms each connected to two connection points of the electric machine element 200. In figure 2, one of the adjustable tensioning arms is denoted with a reference 203 and the connection points connected to the adjustable tensioning arm 203 are denoted with references 205 and 206. Both connection points related to each adjustable tensioning arm are located on a geometric circle that is concentric with a geometric axial center line 207 of the electric machine element 200. Therefore, both connection points related to each adjustable tensioning arm are located a same distance away from the geometric axial center line 207. Each of the adjustable tensioning arms is provided with a tensioning device for directing mutually opposite forces to the connection points connected to the adjustable tensioning arm under consideration in order to adjust the shape of the core structure 201. Therefore, the o shape of the airgap surface of the electric machine element 200 can be adjusted.
O
3 The exemplifying electric machine element 200 illustrated in figure 2 comprises a + 25 housing element 208 that has a cylindrical wall so that the yoke section of the core > structure 201 is against the inner surface of the cylindrical wall. The housing element
E 208 comprises the connection points connected to the adjustable tensioning arms. 5 In this exemplifying case, the housing element 208 comprises projections connected > to the outer surface of the cylindrical wall and protruding radially away from the
N 30 cylindrical wall. In figure 2, two of the projections are denoted with references 209 and 210. The projections constitute the connection points for the adjustable tensioning arms. As shown in figure 2, the cylindrical wall of housing element 208 is between the adjustable tensioning arms and the geometric axial center line 207 of the electric machine element 200.
Figure 3 illustrates an electric machine according to an exemplifying and non-limiting embodiment. The electric machine comprises a first electric machine element 300 according to an exemplifying and non-limiting embodiment. Furthermore, the electric machine comprises a second electric machine element 320. The first and second electric machine elements 300 and 320 are rotatably supported with respect to each other. The axial direction of the electric machine is parallel with the z-axis of a coordinate system 399. The first electric machine element 300 can be for example — such as the electric machine element 100 illustrated in figure 1. In this exemplifying case, the electric machine is an outer rotor electric machine where the first electric machine element 300 is a rotor element and the second electric machine element 320 is a stator element. It is however also possible that an electric machine according to an exemplifying and non-limiting embodiment is an inner rotor electric machine whose stator comprises an electric machine element according to an exemplifying and non-limiting embodiment.
The specific examples provided in the description given above should not be construed as limiting the applicability and/or interpretation of the appended claims.
It is to be noted that lists and groups of examples given in this document are non- exhaustive lists and groups unless otherwise explicitly stated. oO
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Claims (15)
1. An electric machine element (100, 200) comprising a core structure (101, 201), characterized in that the electric machine element comprises adjustable tensioning arms (103, 104, 203) each being connected to two of connection points (105, 106, 205, 206) of the electric machine element, wherein the two of the connection points are located on a geometric circle concentric with a geometric axial center line (107, 207) of the electric machine element, and each of the adjustable tensioning arms is provided with a tensioning device for directing mutually opposite forces to the connection points connected to the adjustable tensioning arm under consideration to adjust a shape of the core structure.
2. An electric machine element according to claim 1, wherein the electric machine element further comprises a housing element (108, 208) having a cylindrical wall so that a yoke section of the core structure is against an inner surface of the cylindrical wall, the housing element comprising the connection points connected to the adjustable tensioning arms.
3. An electric machine element according to claim 2, wherein the housing element (108) comprises projections (109, 110) protruding radially towards the geometric axial center line of the electric machine element and constituting the connection points so that each of the adjustable tensioning arms is, in a radial direction, between the cylindrical wall and the geometric axial center line of the electric machine element and the adjustable tensioning arms are axially a distance 2) away from the core structure. g ro
4. An electric machine element according to claim 2, wherein the housing x element (208) comprises projections (209, 210) connected to an outer surface of I 25 the cylindrical wall and protruding radially away from the cylindrical wall and a © constituting the connection points so that the cylindrical wall is between the 3 adjustable tensioning arms and the geometric axial center line of the electric 2 machine element. N
5. An electric machine element according to any one of claims 1-4, wherein the connection points connected to different ones of the adjustable tensioning arms are located on a same geometric circle concentric with the geometric axial center line.
6. An electric machine element according to claim 5, wherein the adjustable tensioning arms are equally spaced so that the adjustable tensioning arms coincide with sides of a regular geometric polygon.
7. An electric machine element according to any one of claims 1-6, wherein number of the adjustable tensioning arms is at least four.
8. An electric machine element according to claim 7, wherein the number of the adjustable tensioning arms is at least six.
9. An electric machine element according to any one of claims 1-8, wherein the core structure (101, 201) is a segmented core structure comprising circumferentially successive core segments (111, 112, 211, 212).
10. An electric machine element according to any one of claims 1-9, wherein the tensioning device of each of the adjustable tensioning arms is one of the following: a mechanical tensioning device, a hydraulic tensioning device, an electromechanical tensioning device, a pneumatic tensioning device.
11. An electric machine element according to any one of claims 1-10, wherein the electric machine element (100) is a rotor element for an outer rotor electric machine. = 20
12. Anelectric machine element according to any one of claims 1-10, wherein the N electric machine element (200) is a stator element for an inner rotor electric
O . < machine. E
13. An electric machine comprising a first electric machine element (300) and a O second electric machine element (320) rotatably supported with respect to each O 25 other, the first electric machine element being an electric machine element > according to any one of claims 1-12.
14. An electric machine according to claim 13, wherein the electric machine is an outer rotor electric machine in which the first electric machine element is a rotor element and the second electric machine element is a stator element.
15. An electric machine according to claim 13, wherein the electric machine is an inner rotor electric machine in which the first electric machine element is a stator element and the second electric machine element is a rotor element. o O N LÖ Q@ + T [am o O o M LO o O N
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20195396A FI20195396A1 (en) | 2019-05-14 | 2019-05-14 | An electric machine element and an electric machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20195396A FI20195396A1 (en) | 2019-05-14 | 2019-05-14 | An electric machine element and an electric machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| FI20195396A1 true FI20195396A1 (en) | 2020-11-15 |
Family
ID=74063186
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FI20195396A FI20195396A1 (en) | 2019-05-14 | 2019-05-14 | An electric machine element and an electric machine |
Country Status (1)
| Country | Link |
|---|---|
| FI (1) | FI20195396A1 (en) |
-
2019
- 2019-05-14 FI FI20195396A patent/FI20195396A1/en not_active Application Discontinuation
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| FD | Application lapsed |