CA2191933A1 - Method for renewing sliprings - Google Patents

Method for renewing sliprings

Info

Publication number
CA2191933A1
CA2191933A1 CA002191933A CA2191933A CA2191933A1 CA 2191933 A1 CA2191933 A1 CA 2191933A1 CA 002191933 A CA002191933 A CA 002191933A CA 2191933 A CA2191933 A CA 2191933A CA 2191933 A1 CA2191933 A1 CA 2191933A1
Authority
CA
Canada
Prior art keywords
slipring
sliprings
bushing
shrink
smaller
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002191933A
Other languages
French (fr)
Inventor
Werner Haditsch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Asea Brown Boveri Ltd
Original Assignee
ABB Asea Brown Boveri Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ABB Asea Brown Boveri Ltd filed Critical ABB Asea Brown Boveri Ltd
Publication of CA2191933A1 publication Critical patent/CA2191933A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
    • H01R43/14Maintenance of current collectors, e.g. reshaping of brushes, cleaning of commutators

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Control Of Heat Treatment Processes (AREA)
  • General Factory Administration (AREA)
  • Winding, Rewinding, Material Storage Devices (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Manufacturing Of Electrical Connectors (AREA)

Abstract

The method for renewing sliprings of synchronous machines comprises the following method steps:

a) Machining the sliprings on the shaft without remo-ving the sliprings from the shaft, for the purpose of producing a slipring bushing (8, 9), specifically to a radius which is preferably 30 to 40 mm smaller than the nominal radius of the slipring;
b) Heating and subsequently shrinking the new sliprings (6, 7; 6a, 6b, 7a, 7b) consisting of a high-strength Cu-Ni-Be alloy, onto the shrink surfaces, prepared in accordance with step a), of the slipring bushings (8, 9) from the non-drive end (NS) of the machine;
c) Skimming the slipring surfaces of the newly shrunk-on sliprings to the nominal radius (rN).
This renders possible economic repair which, in addition, improves the service life and the electrical properties of the entire slipring arrangement.

Description

~ ~ 2191933 95/179 TITLE OF THE INVENTION

METHOD FOR RENEWING SLIPRINGS

Field of the Invention The invention relates to a method for renewing sliprings of synchronous machines.

Discussion of Backqround Sliprings of synchronous machines, for example turbine-driven generators, normally consist of steel rings arranged in pairs. They are either shrunk in an insulated fashion onto a slipring bushing or in an insulated fashion directly onto the rotor shaft (compare Wiedemann/Kellenberger "Konstruktion elektrischer Machinen" ["Design of electric machines"], Springer-Verlag Berlin, Heidelberg, New York 1967, pages 392, 393).
Sliprings of high-speed machines are necessarily subjected to wear. It is comparatively expensive to replace them.

SUMMARY OF THE INVENTION - -Accordingly, one object of this invention is to provide a novel method for renewing sliprings which, on the one hand, is simple to carry out and, on the other hand, increases the service life and the current transfer properties of the sliprings.
This object is achieved according to the inven-tion by means of the following method steps:
a) Machining both sliprings on the shaft without removing the sliprings from the shaft, for the ~urpose of producing a slipring bushing, specifically to a radius which is preferably 30 to 40 mm smaller than the nominal radius of the slipring;
b) Heating and subsequently shrinking the new sliprings consisting of a high-strength Cu-Ni-Be alloy, onto the shrink surfaces, prepared in accordance with step a), of the slipring bushings from the non-drive end of the machine;
c) Skimming the slipring surfaces of the newly shrunk-on sliprings to the nominal radius.
The method according to the invention offers the possibility of renewing sliprings economically, and moreover increasing the service life of the (new) slip-rings, because the latter also have better running properties in addition to a larger current carrying capacity. Moreover, the invention offers further advan-tages:
- The current transfer losses are reduced, and the brush life is lengthened.
- The loadability of the brushes is increased. The necessary brush number per polarity can therefore be reduced. This produces a further reduction in the brush consumption. Furthermore, there is thereby an increase in the slipring surface uncovered by carbon brushes.
The slipring is thereby more effectively cooled, and the slipring temperature drops, and this in turn favors the operating characteristics of the sliprings.
- When the sliprings are operated in a closed cooling circuit, the reduced carbon consumption produces smaller filter contaminations and thus longer filter lives. Moreover, owing to the reduced overall losses it is also the case that lower exhaust air temperatures, and thus reduced recooling performances are required.
- When refitting existing installations, the possibly increased field current requirement can be ensured by the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained às the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Figure 1 shows a longitudinal section through the non-drive-end shaft end of a turbine-driven generator with two sliprings made from steel;
Figure 2 shows a longitudinal section through the non-drive-end shaft end of the turbine-driven generator according to Figure 1 after the steel sliprings have been turned down and the novel sliprings shrunk on;
Figure 3 shows a modification of the embodiment accor-ding to Figure. 2, with sliprings which respectively comprise two individual rings;
Figure 4 shows a further modification of the embodiment according to Figure 2, with stepped shrink surfaces on a larger scale than in Figure 2; and Figure 5 shows a particularly preferred embodiment of the invention, with sliprings which respec-tively comprise two individual rings with different shrink surfaces and are mounted on shrink surfaces, stepped in a complementary fashion thereto, on the steel rings.- ~-DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein line reference numerals designate identical or corresponding parts through the several views, in Figure two sliprings 1, 2 made from steel are mounted, for example shrunk on, on the non-drive-end shaft end NS of a turbine-driven generator, in an insulated fashion on t.le shaft 5 with the interposition of insulating foils 3, 4. For reasons of simplification, the electrical connection to the exciter terminal studs arranged in a shaft bore has been omitted from the drawing; for the rest, it corresponds to the prior art such as is to be gathered, for example, from the book by Wiedemann/Kellenberger mentioned at the beginning, loc.
cit. Because such sliprings are subjected to wear, they have to be replaced at certain intervals. To date, the sliprings l, 2 have, for this purpose, been heated to several hundred degrees Celsius and then pulled off in the direction of the non-drive-end shaft end. Before shrinking on new sliprings, the insulating foil 3, 4, damaged during pulling off, has been replaced.
By contrast, the invention adopts a different approach:
The existing sliprings 1, 2 are not removed, but they are turned down to a radius r which is smaller by the thickness d (typically 30 mm) of the slipring 6 or 7 to be shrunk on anew than the nominal outside radius rN of the slipring. The previous sliprings now form, as it were, slipring bushings 8, 9 for the sliprings 6, 7 to be shrunk on anew.
The sliprings to be shrunk on anew consist according to the invention of a hardenable copper alloy with alloying additions of Ni or Be. An alloy which is available commercially under the designation of HOVADUR
CuNiBe from the Schmelzmetall AG Company, CH-6482 Gurtnellen/Uri (data sheet HOVADUR CuNiBe, undated) has proved to be particularly advantageous in this Acase.
This copper alloy has alloying additions of approximately 1.8% Ni and approximately 0.4~ Be. In the hardened "normal state", it already has a high hardness and thermostability in conjunction with good electrical and thermal conductivity. In addition, this alloy can also be delivered in heat-treated form and in a so-called "special state". In this form of supply, this alloy achieves strength values which correspond to those of ste_l. Its electrical and thermal conductivity, by contrast, correspond to those of copper.
The new sliprings 6, 7 are heated to approxi-mately 200C and shrunk onto the slipring bushings 8 ~ 21 91933 and g, respectively (compare Figure 2). Because of the high modulus of elasticity and the high yield point of the copper alloy, an optimum shrink fit results upon cooling and withstands all the operating stresses. The newly shrunk-on sliprings 6, 7 are subsequently skimmed to nominal radius rN.
In order to facilitate slipping the inner slipring 7 on over the slipring bushing 8 of the outer slipring 6, it is expedient to skim the outer slipring 1 to a radius which is smaller by the measure ~ and, consequently, to increase the thickness of the to be shrunk on slipring 6 anew by this difference ~ (compare Figure 2). A difference ~ of between 1 and 2 mm suffices in this case.
Sliprings of medium and large turbine-driven generators have an axial width of the order of magnitude of 200 to 400 mm. Narrow rings made from said copper alloy - they are normally produced from a blank by forging - are more economical to produce than wide rings; it is also easier to manipulate them during installation. For this reason, it is expedient to form the (new) slipring from a plurality of mutually identical individual rings 6a, 6b or 7a, 7b, as is represented in Figure 3 for a slipring comprising two individual rings. - ~-It is expedient, here, as well, to make theradius r of the outer slipring bushing 8 smaller by the measure ~ than the inner slipring bushing 9, and conse-quently to increase the thickness of the two partial rings 6a, 6b by ~.
In the embodiment represented in Figure 4, the shrink surfaces on the two slipring bushings 8, 9 and, consequently, also the associated shrink surfaces on the inner circumference of th~ sliprings 6 and 7 are stepped. The respective radii are denoted by rl, r2, r3 and r4, it being the case that rl ~ r2 > r3 > r4 holds, in order to be able to slip the inner slipring 7 over the outer slipring bushing 8. This step additionally - 6 - 95/17g secures the sliprings 6, 7 in the axial direction and also renders installation easier, because an axial stop is available during the shrinking on owing to the step.
The embodiment according to Figure 4 can also be carried over to individual rings 6a, 6b or 7a, 7b as illustrated in Figure 5. There, the individual rings 6a, 6b or 7a, 7b are respectively seated on stepped shrink surfaces with the radii r1, r2, r3 and r4, it being the case, again, that r1 > r2 > r3 > r4 holds.
The invention is not, of course, restricted to renewing sliprings shrunk directly onto the rotor shaft. It can, of course, also be applied in the case of slipring arrangements in which the steel sliprings are shrunk onto a slipring bushing or onto a preshrunk ring, as is represented, for example, in Figure 386 and Figure 388 on page 392 in the book by Wiedemann/Kellenberger mentioned at the beginning.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims (5)

1. Method for renewing sliprings of synchronous machines, defined by the following method steps:
a) Machining the sliprings on the shaft without remo-ving the sliprings from the shaft, for the purpose of producing a slipring bushing (8, 9), specifically to a radius which is preferably 30 to 40 mm smaller than the nominal radius of the slipring;
b) Heating and subsequently shrinking the new sliprings (6, 7; 6a, 6b, 7a, 7b) consisting of a high-strength Cu-Ni-Be alloy, onto the shrink surfaces, prepared in accordance with step a), of the slipring bushings (8, 9) from the non-drive end (NS) of the machine;
c) Skimming the slipring surfaces of the newly shrunk-on sliprings to the nominal radius (rN).
2. The method as claimed in claim 1, wherein in step a) the non-drive-end slipring (1) is brought to a smaller diameter, preferably 2 to 3 mm smaller, than the other slipring(2).
3. The method as claimed in claim 1, wherein in step b) a plurality of mutually butt-mounted individual rings (6a, 6b, 7a, 7b) are used per slipring.
4. The method as claimed in claim 2, wherein in step a) the machining is performed in such a way that stepped shrink surfaces with different radii (r1, r2, r3 and r4) are produced on the remaining slipring bushing (8, 9), and that for this purpose the slipring (6, 7) to be shrunk on has complementary stepped inner surfaces, the outside diameter of the largest shrink surface on the non-drive-end slipring bushing (8) being smaller than the outside diameter of the smallest shrink surface on the neighboring slipring bushing (9).
5. The method as claimed in claim 3, wherein in step a) the machining is performed in such a way that stepped shrink surfaces with different radii (r1, r2, r3, r4) are produced on the remaining slipring bushing (8, 9), and that for this purpose the individual rings (6a, 6b, 7a, 7b) to be shrunk on have complementary inner surfaces, the outside diameter of the largest shrink surface on the non-drive-end slipring (8) being smaller than the outside diameter of the smallest shrink surface on the neighboring slipring bushing (9).
CA002191933A 1995-12-04 1996-12-03 Method for renewing sliprings Abandoned CA2191933A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19545142.2 1995-12-04
DE19545142A DE19545142A1 (en) 1995-12-04 1995-12-04 Procedure for renewing slip rings

Publications (1)

Publication Number Publication Date
CA2191933A1 true CA2191933A1 (en) 1997-06-05

Family

ID=7779121

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002191933A Abandoned CA2191933A1 (en) 1995-12-04 1996-12-03 Method for renewing sliprings

Country Status (8)

Country Link
EP (1) EP0778641A2 (en)
JP (1) JPH09180852A (en)
CN (1) CN1165417A (en)
CA (1) CA2191933A1 (en)
DE (1) DE19545142A1 (en)
HR (1) HRP960562A2 (en)
PL (1) PL317305A1 (en)
ZA (1) ZA969671B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11594943B2 (en) 2021-07-14 2023-02-28 Andritz Hydro Corp. In place machining of collector ring

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101823156B (en) * 2009-03-05 2011-12-07 鞍钢股份有限公司 Electrified turning method of exciting current-collecting ring of frequency-conversion synchronous motor
CN102205424A (en) * 2010-03-31 2011-10-05 上海宝钢设备检修有限公司 On-line turning method for slip ring of synchronous rolling mill spindle
CN104196750B (en) * 2014-09-01 2016-05-18 青蛙泵业有限公司 A kind of deep well pump rotor major axis and processing technology thereof
CN111682714B (en) * 2020-05-28 2021-04-30 三立(厦门)汽车配件有限公司 Motor rotor slip ring maintenance process

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE285525C (en) *
DE249731C (en) *
US2198395A (en) * 1938-07-18 1940-04-23 Harry B Spear Collector ring
DE903944C (en) * 1944-08-30 1954-02-11 Siemens Ag Slip ring set
CH308105A (en) * 1951-07-10 1955-06-30 Siemens Ag Contact device with spring-loaded contact segments for a pin-like switching element.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11594943B2 (en) 2021-07-14 2023-02-28 Andritz Hydro Corp. In place machining of collector ring

Also Published As

Publication number Publication date
HRP960562A2 (en) 1997-08-31
JPH09180852A (en) 1997-07-11
PL317305A1 (en) 1997-06-09
ZA969671B (en) 1997-06-12
EP0778641A2 (en) 1997-06-11
CN1165417A (en) 1997-11-19
DE19545142A1 (en) 1997-06-05

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