GB2619163A

GB2619163A - Centering device for rotating machine

Info

Publication number: GB2619163A
Application number: GB2305765.6A
Authority: GB
Inventors: Hoenig Christian
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2023-04-19
Filing date: 2023-04-19
Publication date: 2023-11-29
Also published as: GB202305765D0

Abstract

A centring device 500 for minimising rotor vibration in a rotating electrical machine, comprising a first member 514 comprising an outer surface 516 and an inner surface 502, a contact pad 504 on the first member, and adjusting devices 510, the adjusting devices being in connection with the pad. A second member 506 is connected to the inner surface of the first member, the second member comprising through holes 508, wherein the adjusting devices are arranged to provide a force to the contact pad providing movement of the pad. The through holes may include a first and second through hole, wherein an opening 512 is arranged between these through holes. The pad may comprise metal and a teflon (RTM) layer. The pad may also include an additional mass. The second member 506 may be tapered having a first width 518 wider than a second width 520, the second member may be arranged on the inner surface along the first width, the second width opposite the first width. A plurality of centring devices may be attached to the rotor of the machine and arranged with respect to inner and outer supports of the rotor and pretensioned against the inner support to provide centring of the rotor end windings where the inner and outer supports may provide centrifugal support to the end windings.

Description

CENTERING DEVICE FOR ROTATING MACHINE

BACKGROUND

[0001] Rotating electrical machines include a stator and a rotor having a common axis. The stator remains stationary during operation and the rotor rotates around an axis common to the stator and rotor. Examples of rotating electrical machines includes generators, exciters, and motors.

BRIEF SUMMARY

[0002] In one aspect, a centering device that minimizes rotor vibration of a rotating machine is provided. The centering device includes first and second members. The first member includes an inner surface, a contact pad, and adjusting devices. The second member, which is attached to the first member, includes a plurality of through holes suitable for attaching the centering device to the body of the rotor. The adjusting devices are arranged to provide a force to the contact pad providing a movement of the contact pad [0003] The outer surface may be convex to match a curve of the inner support of a rotor, The inner surface may be concave, e.g, mirroring the curve of the outer surface.

[0004] The plurality of through holes includes a first through hole and a second through hole. An opening may be arranged between the first through hole and the second through hole. The opening corresponding to an opening in the rotor body. For example, a cooling hole or a tie bolt hole.

[0005] The second member includes a first width and a second width. The first and second members may form an L-shape centering device. The second member may be tapered where the first width is wider than the second width.

[0006] A contact pad includes a substrate formed of or comprising metal. The contact pad includes a Teflon coating, at least on one side of the substrate. The contact pad may include an additional mass on or in the substrate.

[0007] The position of the contact pad is adjustable. The contact pad can be moved inward. Inward is towards the inner surface and the second member. The contact pad can be moved outward. Outwards is away from the inner surface and the second member. The adjustment is via a force to the contact pad by the plurality of adjusting devices.

[0008] In another aspect, a rotor including the centering device is provided. The rotor includes a rotor body, a plurality of centering devices attached to the rotor body, an inner support arranged radially outward from the plurality of centering devices, rotor end windings arranged radially outward from the inner support, and an outer support arranged radially outward from the rotor end windings.

[0009] The contact pad of each of the plurality of centering devices is pre-tensioned against the inner support.

[0010] The centering devices provide centering of the rotor end windings, and the inner support and outer support ring provide centrifugal support to the end windings.

[0011] The position of the contact pad is adjustable. The contact pad can be moved inward, away from the inner support. The contact pad can be moved outward toward the inner support. The adjustable movement of the contact pad is provided by the adjusting devices and/or additional mass added to the contact pad. The adjusting devices, contact the surface of the contact pad and add pressure to move the contact pad outward or decrease pressure to move the pad inward. Increasing the mass of the contact pad pushes the contact pad out by centrifugal force during operation of the rotating machine.

100121 The inner support is formed of a material with low electrical conductivity that has a conductivity 10 or less. For example, glass. The inner support may include a ring that is formed of ring sections and relief structures. The relief structures are arranged in between adjacent ring sections.

[0013] The plurality of through holes of the centering device align with holes in the rotor body in order to attach the centering devices to the rotor body. The centering device may include an opening which aligns with a cooling hole or tie bolt on the rotor body.

100141 The outer support may comprise or be formed of carbon fibre.

100151 The rotor is suitable for a low voltage or high voltage operation. Low voltage is greater than 0 and below 600 volts and high voltage is above 600 volts.

[0016] In another aspect, a rotating machine is provided. The rotating machine includes a stator and the rotor as described above. The rotor is arranged radially inward from the stator. The rotating machine may be an asynchronous generator.

100171 A method of centering rotor end windings is provided. The centering device is mechanically attached to the rotor prior to the installation of the rotor winding and the support structures. The inner support is mounted on the centering devices. After mounting the inner support, the rotor winding and end winding structure is installed in the rotor. After installing the windings and end windings, the outer support is installed at the outer diameter of the end winding.

[0018] The contact pads are adjusted at least once during the method, e.g. after the mounting of the inner support, after the installing of the rotor windings, after the installation of the outer support. Each of the contact pads can be adjusted independently to provide the needed tension between the contact pad and the inner support. Via the adjustment of the contact pads, the centering devices are used to center the complete end winding relative to the rotor centerline and apply pressure from the end winding inner diameter through the end winding and inner support to the outer support.

BRIEF DESCRIPTION OF THE DRAWINGS

100191 To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

100201 FIG. 1 is a cross-sectional view of a rotating machine taken along the centerline, rotational, or longitudinal axis.

100211 FIG. 2 is a perspective view of a rotor suitable for use in the rotating machine of FIG. 1.

[0022] FIG. 3 illustrates the end winding section of the rotor in the rotating machine of FIG. 1 [0023] FIG. 4 illustrates a further embodiment of the end winding section of a rotor in an rotating machine.

100241 FIG. 5A illustrates a centering device.

[0025] FIG. 5B illustrates an cross section view of the centering device of FIG. 5A.

[0026] FIG. 6 illustrates a portion of an electric machine with the centering device of FIG. 5A and FIG. 5B.

[0027] FIG. 7 illustrates an embodiment of an inner support.

[0028] FIG. 8 illustrates a contact pad of the centering device of FIG. 5A and FIG. 5B. [0029] FIG. 9 illustrates an method in accordance with one embodiment.

DETAILED DESCRIPTION

100301 Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0031] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0032] Also, it should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms "including," "having," and "comprising," as well as derivatives thereof, mean inclusion without limitation. The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term "or" is inclusive, meaning and/or, unless the context clearly indicates otherwise. The phrases "associated with" and "associated therewith," as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc, described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[00331 Also, although the terms "first", "second", "third" and so forth may be used herein to refer to various elements, information, functions, or acts, these elements, information, functions, or acts should not be limited by these terms. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0034] In addition, the term "adjacent to" may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion, unless the context clearly indicates otherwise. Further, the phrase "based on-is intended to mean "based, at least in part, on" unless explicitly stated otherwise. Terms "about" or "substantially" or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0035] As illustrated in FIG. 1, a rotating machine 100, such as a a synchronous turbo generator, includes a stator 102 and a rotor 200 supported for rotation within the stator 102. The stator 102 includes a stator housing 104 that surrounds and substantially encloses a stator core 106. The stator core 106 is often made-up of a number of laminations 108 stacked in a longitudinal direction (along a rotational axis). Each lamination 108 includes cut outs or is otherwise shaped to define the desired features of the rotor core, including a bore 110 that is sized to receive the rotor 200.

[0036] In some constructions, a stator cooling system 112 is provided to cool the stator 102 and improve the efficiency and power density of the stator 102. A cooling gas or liquid can be employed as a stator coolant for the stator cooling system 112.

[00371 The illustrated rotor 200 is supported for rotation by a bearing 114 positioned at each end of the rotor 200. A turbine coupling 116 is positioned at one end of the rotor 200 to facilitate connection of the rotor 200 to a turbine (e.g., combustion turbine, steam turbine, hydro turbine, etc.) or to another prime mover. The opposite end of the rotor 200 may include an exciter coupling 118 that allows for connection to an exciter or other rotating equipment.

The rotor 200 includes a rotor shaft 120, and a rotor body, and an outer support 122, at each end of the rotor body 124, that are coupled to the rotor body 124.

100381 FIG. 2 illustrates the rotor 200 of FIG. 1 in greater detail. The rotor body 124 includes a series of rotor slots 202 that extend longitudinally along the rotor shaft 120. Rotor windings 204 are positioned within the rotor slots 202 to define one or more pairs of poles. In the illustrated construction two poles are formed by the rotor slots 202. However, other constructions could include four poles, six poles or more poles if desired.

[0039] FIG. 3 illustrates the end winding section of FIG. 2 in more detail. Rotor end windings 302 are formed from the rotor windings 204 at each end of the rotor body 124. To prevent excessive vibration, the rotor end windings 302 need to be centered, in relation to the rotor 200. To provide and maintain the centering as well a protect the rotor end windings 302 from centrifugal forces, the outer support 122 is arranged on the outside diameter of the respective rotor end windings 302 at each end of the rotor body 124. The illustrated outer support 122 is embodied as a retaining ring that is typically formed of high alloy non-magnetic steel and is shrunk onto the rotor body. Retaining rings are commonly used in rotating machines that when in operation, the rotor end winding 302 have a low voltage. Low voltage is appropriate due to the conductivity of steel. Low voltage is defined herein as voltage greater than 0 and below 600 volts. Retaining rings are common in synchronous turbo generators.

[0040] FIG. 4 illustrates the end winding of a rotating machine 400. The rotating machine 400 is similar to FIG. 1 in that the rotor end windings are formed from windings in rotor slots formed on the rotor. A centering arrangement 410 includes an inner support 406 and outer support 408.

[0041] The inner support 406 is attached to the rotor body 402. The inner support 406 is formed as a ring and arranged radially inward of the rotor end windings 404. The outer support 408 is arranged radially outward of the rotor end windings 404.

[0042] The outer support 408 is applied to the rotor end windings 404 with a pre-tension to prevent the rotor end windings 404 from lifting off from the inner support 406. It is common for the outer support 408 to be a insulation that is wrapped around the rotor end windings 302 or steel wire that is would around the rotor end windings 404. The rotating machine 400 as illustrated is an exciter.

[0043] FIG. SA illustrates an embodiment of a centering device 500 that centers the rotor end windings 602 to minimizing rotor vibration. The illustrated centering device 500 includes a first member 514 and a second member 506 that is attached to the first member 514.

100441 The first member 514 includes an outer surface 516, an inner surface 502, a contact pad 504, and a plurality of adjusting devices 510. The adjusting devices 510, e.g., a bolt, screw, spring, etc., facilitate a manual adjustable movement of the contact pad 504.

[0045] The illustrated embodiment shows the second member 506 that includes an opening 512, and a plurality of through holes 508, wherein a first of the plurality of through holes 508 is on one side of the opening 512 and a second of the plurality of through holes 508 on the opposite side. It would be understood that the number of openings 512 and the number of through holes 508 is merely an example. Furthermore, it would be possible to eliminate the opening 512.

[0046] The second member 506 includes a first width 518 and a second width 520. The second member 506 is adjoined along the first width 518 to the first member 514 on the inner surface 502. According to the illustrated embodiment, the second member is tapered where the first width 518 is wider than the second width 520.

[0047] FIG. 5B illustrates a cross section of the centering device 500 as illustrated in FIG 5k The illustration shows in more detail how the adjusting devices 510 provides the adjustable movement 522, 524 of the of the centering device 500. The adjusting devices 510 are in communication with the centering device 500 to apply a force on the contact pad 504. The movement of the contact pad 504 is made by changing the force. The movement of the centering device 500 being in the direction of force. For example, an increase in force moves the contact pad 504 outward 522 and a decrease in force moves the contact pad 504 inward 524.

[0048] FIG. 6 illustrates a section of a rotating machine 600 with centering device 500. The rotating machine 600 includes a rotor 606 and stator 614 with a common axis. A portion of the windings on the rotor 606 that extend beyond the rotor body 604, are the rotor end windings 602. The rotor end windings 602, when not centered, will vibrate during operation of rotating machine 600. This vibration can cause damage to the rotating machine 600.

[0049] The rotor 606 includes an inner support 608, the rotor end windings 602, the centering device 500, and an outer support 610.

[0050] The inner support 608 is formed as a ring. The illustrated inner support 608 is formed of glass.

[0051] The rotor end windings 602 are arranged on the inner support 608. The rotor end windings 602 are radially outward from the inner support 608.

100521 The centering device 500, which is attached to the rotor body 604, is arranged radially inward of the inner support 608. The contact pad 504 of the centering device 500 is in contact with the inner support 608. The contact pad 504 of the centering device 500 is pre-tensioned on the inner support 608. The tension between the centering device 500 and the contact pad 504 is adjustable via the adjusting devices 510.

[0053] An outer support 610 is applied to the rotor end windings 602. The outer support 610, can be applied to the rotor end windings 602 without pre-tensioning. The illustrated outer support 610 is a carbon fiber retaining ring. The outer support 610 is separated from the rotor body 604 by a gap 612. A cooling path to the rotor end windings 602 is provided via the gap 612.

[0054] By way of adjusting of the contact pads 504, the centering devices 500 are used to center the end windings relative to the rotor axis, and to apply pressure from the end winding inner diameter through the end windings and inner support 608 to the outer support 610.

[0055] The rotor 606 is suitable for end windings having high voltage or low voltage.

[0056] FIG. 7 illustrates an embodiment of the inner support 608. The inner support 608 includes a ring 702. The ring 702 is formed of ring sections 706 and relief structures 704, which can compensate for thermal expansion. A relief structure 704 is arrange in between adjacent ring sections 706. At least one centering device 500 is arranged in each ring section 706.

100571 FIG. 8 illustrates the contact pad 504 in more detail. The contact pad 504 includes a substrate 806. The substrate 806 is formed or comprises a metal. It is possible to add a coating 802 to the substrate 806 at least on the side that contacts the inner support 608. An additional mass 804 may be included, with or without the coating 802. The additional mass 804 provides further adjustment of the centering device 500 during the operation of the electric rotating machine 600. As the rotor 606 rotates, the centrifugal force created on the additional mass 804 increases the force on the contact pad 504; thereby, increasing the tension between the contact pad 504 and the inner support 608. It would be understood that the even distribution of the additional mass 804 is for illustration purposes only, and that the additional mass 804 maybe distributed in any manner on or in the substrate 806.

[0058] FIG. 9 illustrates a method 900 of centering rotor end windings 602. The method 900 includes attaching the centering device to the rotor body block 902. Mounting the inner support to the centering device 904. Installing the rotor windings having the rotor end windings on the rotor 906. Mounting the outer support to centering device 908. Adjusting the contact pad of each of the plurality of centering devices to create a tension between the contact pad and the inner support to maintain centering 910.

[0059] The adjusting of the contact pad is done at least once after the mounting of the inner support, after the installation of the rotor end windings, after the mounting of the outer support.

[0060] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0061] None of the description in the present application should be read as Implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.

LISTING OF DRAWING ELEMENTS

rotating machine 102 stator 104 stator housing 106 stator core 108 lamination bore 112 stator cooling system 114 bearing 116 turbine coupling 118 exciter coupling rotor shaft 122 outer support 124 rotor body rotor 202 rotor slot 204 rotor winding 302 rotor end winding 304 rotating machine 400 rotating machine 402 rotor body 404 rotor end windings 406 inner support 408 outer support 410 centering arrangement 500 centering device 502 inner surface 504 contact pad 506 second member 508 through hole 510 adjusting device 512 opening 514 first member 516 outer surface 518 first width 520 second width 522 outward 524 inward 600 rotating machine 602 rotor end windings 604 rotor body 606 rotor 608 inner support 610 outer support 612 gap 614 stator 702 ring 704 relief structure 706 ring section 802 coating 804 additional mass 806 substrate 902 block 904 block 906 block 908 block 910 block

Claims

CLAIMSWhat is claimed is: 1. A centering device 500 for minimizing rotor vibration in a rotating machine, comprising: a first member 514 comprising an outer surface 516 and an inner surface 502, a contact pad 504, and a plurality of adjusting devices 510, the plurality of adjusting devices 510 in connection with the contact pad 504; and a second member 506 connected to the inner surface 502 of the first member 514, the second member 506 comprising a plurality of through holes 508, wherein the plurality of adjusting devices a 510 are arranged to provide a force to the contact pad 504 providing a movement of the contact pad 504.
2. The centering device 500 according to claim 1, wherein the plurality of through holes 508, includes a first through hole and a second through hole, wherein a opening 512 is arranged between the first through hole and the second through hole.
3. The centering device 500 according to any of claim 1 or 2, wherein the contact pad 504 comprises metal.
4. The centering device 500 according to any one of claims 1 to 3, wherein the contact pad 504 comprises a teflon layer.
5. The centering device 500 according to any of any one of claims 1 to 4, wherein the contact pad 504 includes an additional mass 806.
6. The centering device 500 according to any of any one of claims 1 to 5, wherein the second member 506 is tapered having a first width 518 wider than a second width 520, the second member 506 is arranged on the inner surface along the first width 518, the second width 520 opposite the first width 518.
7. A rotor 606 comprising: a rotor body 124; a plurality of centering devices 500 as claimed in any one of claims 1 to 6 attached to the rotor body 604; an inner support 608 arranged radially outward from the plurality of centering devices 500; rotor end windings 602 arranged radially outward from the inner support 608; and an outer support 610 arranged radially outward from the rotor end windings 602; wherein the contact pad 504 of each of the plurality of centering devices 500 is pre-tensioned against the inner support 608; wherein the plurality of centering devices 500 provide centering of the rotor end windings 602, and wherein the inner support 608 and outer support ring provide centrifugal support to the end windings.
8. The rotor 606 according to claim 7, wherein a cooling gap 612 is formed between the outer support 610 and the rotor body.
9. The rotor 606 according to claim 7 or 8, wherein the outer support 610 is carbon fibre.
10. The rotor 606 according to any one of claims 7 to 9, wherein the inner support 608 is glass.
I I. The rotor 606 according to any one of claims 7 to 10, wherein the inner support 608 comprises a 702 that is formed in 706 with relief structures 704 formed between adjacent ring sections 706, and wherein the plurality of centering devices 500 are arranged on the inner support 608 between relief structures 704.
12. A rotating machine 600 comprising: a stator; the rotor 606 as claimed in any one of claims 7 to 11 arranged radially inward from the stator.
13. The rotating machine 600 of claim 12 wherein the rotating machine 600 is an asynchronous generator.
14. The rotating machine 600 of claim 12 or 13, wherein the rotor end windings 602 are configured for high voltage.
15. A method of centering rotor end windings 602 of a rotor 606 as claimed in any one of claims 7 to 9, comprising: attaching the plurality of centering devices to the rotor body; mounting the inner support to plurality of centering devices; installing the rotor windings having the rotor end windings installed on the inner support mounting the outer support to entering device; and adjusting the contact pad of each of the plurality of centering devices to create a tension between the contact pad and the inner support to maintain centering.