United States Patent c191
`Scherzinger et al.
`
`(54] EXCITER STATOR INSULATING BOBBIN
`
`(75]
`
`Inventors: William M. Scherzinger, Brick; Yefim
`Novoselsky, Old Bridge; Leon Kasdan.
`West Long Branch, all of N.J.
`
`(73] Assignee: AlliedSignal Inc., Morristown, N.J.
`
`(21] Appl. No.: 653,529
`
`May 24, 1996
`(22] Filed:
`..................................................... B02K 15/04
`Int. Cl.6
`(51]
`(52] U.S. CI ............................. 310/194; 310/65; 310/215;
`310/269; 310/214; 336/198; 336/192; 336/118.41
`(58] Field of Search .............................. 310/194, 65, 215,
`310/214, 269; 336/192. 198, 118.41
`
`(56]
`
`References Cited
`
`U.S. PATENf DOCUMENfS
`
`I IIII IIIII Ill II Ill II II Ill I Ill II IIII I IIII II
`
`US005698923A
`[HJ Patent Number:
`[45J Date of Patent:
`
`5,698,923
`Dec. 16, 1997
`
`4,217,690
`4,520,288
`
`8/1980 Morreale ................................... 29/596
`5/1985 Santi ....................................... 310/194
`
`Primary Examiner-Clayton E. LaBalle
`Assistant Examiner-Timothy A. J. Williams
`Attome)\ Agent, or Firm-Verne E. Kreger, Jr.
`
`[57]
`
`ABSTRACT
`
`A stator insulating bobbin is disclosed including a plurality
`of insulating elements. These insulating elements are con(cid:173)
`figured and dimensioned to substantially enclose and insu(cid:173)
`late an inner surface of a stator assembly. Each of the
`insulating elements includes a first flange portion and a
`second flange portion joined by an intermediate web portion.
`
`4,075,790
`
`2/1978 Foldes ..................................... 3361192
`
`17 Claims, 4 Drawing Sheets
`
`44
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`U.S. Patent
`
`Dec. 16, 1997
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`Sheet 1 of 4
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`Mitsuba - 1005
`Page 2 of 7
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`U.S. Patent
`
`Dec. 16, 1997
`
`Sheet 2 of 4
`
`5,698,923
`
`FIG. 1 F
`PRIOR ART
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`U.S. Patent
`
`Dec. 16, 1997
`
`Sheet 3 of 4
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`5,698,923
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`U.S. Patent
`
`Dec. 16, 1997
`
`Sheet 4 of 4
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`5,698,923
`
`FIG. 3
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`

`1
`EXCITER STATOR INSULATING BOBBIN
`
`5,698,923
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`2
`insulating bobbin made up of a plurality of insulating
`elements configured to at least partially enclose a stator pole,
`each of the insulating elements having a first flange portion
`and a second flange portion joined by an intermediate web
`5 portion. The separate elements, when installed, interfit to
`insulate the stator assembly.
`Preferably, the stator insulating bobbin is made up of two
`identical elements of high temperature insulating material
`which form fit onto the stator pole.
`
`BRIEF DESCRIPITON OF THE DRAWINGS
`
`Understanding of the present invention and the various
`aspects thereof will be facilitated by reference to the accom(cid:173)
`panying figures, submitted for purposes of illustration only
`and not intended to define the scope of the invention, in
`which:
`F1GS. lA-E illustrate conventional insulator elements
`used to insulate stator assemblies;
`F1G. lF is a side view of an exciter stator assembly
`mounting the insulator elements of F1GS. lA-E;
`F1G. 2 is a perspective view in partial cross-section of a
`stator insulating bobbin in accordance with one embodiment
`of the present invention; and
`F1G. 3 is a side view in cross-section of a stator assembly
`mounting the stator insulating bobbins of F1G. 2.
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`The present invention relates to electric motors generally
`and, more particularly, to a novel insulating bobbin for
`electric motor stator assemblies.
`2. Description of Related Art
`Electric motors and generators are well known devices
`which establish and control electromagnetic fields to effect 10
`rotary mechanical motion.
`An exciter is a separate synchronous salient pole machine
`encapsulated in the same housing with a main generator. The
`exciter generates 3 phase AC power which is rectified.
`usually by rotating diodes, and supplied to the rotating DC
`field of the main generator. In the manufacture of electric
`motors and generators, coils or windings of electrically
`conductive wire are wrapped around each of the exciter
`stator poles. In addition to the non-conductive insulation on
`the wire, the stator poles are separately insulated using a
`variety of insulators and multiple wrappings of nomex tape.
`Referring to F1GS. lA-lE, conventional insulators are illus(cid:173)
`trated. F1G. lA shows a bottom insulator 2 and F1G. lC is
`a top insulator 4. A pole insulator 6 is shown in F1G. 1B and
`a fork clip 8 is shown in F1G. lD. A strip of nomex tape 10
`is illustrated in F1G. lE.
`F1G. lF shows an exciter stator assembly 20 with con(cid:173)
`ventional insulators mounted thereon. The exciter stator
`assembly 20 has an outer surface 22 and an inner surface 24. 30
`Reference is now made to the figures, in which similar or
`The inner surface is provided with a multiplicity of radially
`extending stator poles 26 having flaired interfaces 28. The
`identical elements are given consistent identifying numerals
`stator poles 26 define a multiplicity of longitudinal channels
`throughout the various figures. F1GS. 2 and 3 illustrate an
`30 for receiving insulated wire or foil (not shown) to form
`exciter stator insulating bobbin configuration in accordance
`the stator coil.
`35 with a preferred embodiment of the present invention.
`Although the invention is described and illustrated in the
`The bottom of the stator assembly is insulated by two
`bottom insulators 2 (nomex strips with notches for each
`context of an electric generator, it will be appreciated that
`pole). These bottom insulators 2 are assembled from each
`this invention may be used in conjunction with other well
`side of the stator core. The pole insulators 6 are positioned
`known electric motor structures.
`Referring now to F1G. 2, a novel stator insulating bobbin
`adjacent the stator poles 26 and are wrapped with several 40
`for exciter stator assembly 20 is shown generally at 32.
`layers of nomex tape 10. Top insulators 4 are typically slid
`Stator insulating bobbin 32 is U-shaped and is preferably
`into place by hand on each stator pole 26. Fork clips 8 are
`temporarily installed by hand on each stator pole 26 during
`molded from a high temperature insulating material such as.
`the winding process to prevent the top insulators 4 from
`for example, Rynite FR530. or Ryton available from
`45 Dupont. In the embodiment of F1G. 2, the stator insulating
`bending.
`bobbin 32 is made up of two substantially identical (See
`The insulated wire and the complex system of multiple
`F1G. 3) molded insulating elements 34 which are configured
`insulator structure are used to insure that the stator coils do
`not ground out when the pulses of electrical current are
`and dimensioned to form fit and snap into place around the
`stator pole 26.
`generated. The insulation may, however, be damaged or
`Each insulating element 34 includes a first flange portion
`cracked during winding, installation, operation and/or 50
`36 and a second flange portion 38 joined by a web portion
`servicing, resulting in machine failure. The repair of a
`40. First flange portion 36 includes an inner surface 42
`machine with shorted insulation is quite expensive.
`which abuts an undersurface 44 of flaired interface 28. A
`Accordingly, it is an object of the present invention to
`bevel 46 is formed on a leading edge of first flange portion
`provide a novel stator insulating bobbin which increases
`reliability and overall motor life while simplifying assembly 55 36 and extends in a hemispherical configuration around an
`end portion of insulating element 34. This bevel 46 facili-
`and stator construction.
`It is a further object of the present invention to provide a
`tates automated winding of the stator core by providing a
`positive clearance and angle as compared to conventional
`novel stator insulating bobbin construction which facilitates
`uniform and inexpensive fabrication.
`insulators.
`Other objects of the present invention, as well as particu- 60 Web portion 40 includes an inner surface 48 which
`frictionally abuts radially extending portions or sidewalls SO
`lar features, elements and advantages thereof, will be clari-
`of stator pole 20. Although insulating elements 34 are shown
`fled in or be apparent from the following description and the
`as snap fitting or frictionally engaging the stator pole 20,
`accompanying figures.
`other configurations are also contemplated including inter-
`65 locking structure integrally formed with the elements to
`allow them to engage one another. This interlocking struc(cid:173)
`ture may include hermaphroditically configured portions
`
`15
`
`20
`
`25
`
`DEfAil..ED DESCRIPITON OF THE
`PREFERRED EMBODIMENT
`
`SUMMARY OF THE INVENTION
`The present invention achieves the above objects, among
`others, by providing, in a preferred embodiment, a stator
`
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`5,698,923
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`3
`located on mating ends of the insulating elements or tongue
`and groove structure formed on abutting surfaces.
`Second flange portion 38 extends from web portion 40 at
`an acute angle e (See FIG. 3) and includes an inner surface
`52 which abuts and insulates a portion of the floor of channel 5
`30.
`In this preferred configuration a pair of identical insulat(cid:173)
`ing elements 32 are positioned on each stator pole 26 and
`remain in place while the winding process is performed.
`Referring now to FIG. 3, exciter stator assembly 20 is
`shown with stator insulating bobbins 32 in place on each
`stator pole 26. Each of the stator insulating bobbins combine
`to cover and insulate substantially the entire inner surface 24
`of the exciter stator assembly 20. This novel method of
`insulating the magnetic core of a stator greatly simplifies the
`design, increases the dielectric strength and reduces parts
`and assembly time. Further generator life and reliability is
`enhanced.
`It will be understood that various modifications may be
`made to the embodiments disclosed herein. For example, as
`mentioned above, this invention may be used in conjunction
`with electric motor structures other than the exciter stator
`shown above. Accordingly, the above description should not
`be construed as limiting, but merely as exemplifications of
`preferred embodiments. Those skilled in the art will envision
`other modifications within the scope and spirit of the claims
`appended hereto.
`We claim:
`1. A stator insulating bobbin comprising:
`a plurality of insulating elements configured to at least
`partially enclose a stator pole, each said insulating
`element having a first flange portion having a beveled
`leading edge and a second flange portion joined by an
`intermediate web portion, said elements interfitting to
`insulate a stator assembly.
`2. A stator insulating bobbin as in claim 1, wherein a pair
`of insulating elements are configured to at least partially
`enclose a stator pole.
`3. A stator insulating bobbin as in claim 2. wherein each
`of the insulating elements is identical to the other insulating
`elements.
`4. A stator insulating bobbin as in claim 1, wherein the
`insulating elements snap fit into position on the stator pole.
`5. A stator insulating bobbin as in claim 1, wherein the
`insulating elements are molded from a high temperature
`insulating material.
`6. A stator insulating bobbin as in claim 1, wherein
`respective outer edges of adjacent second flange portions are
`
`10
`
`4
`configured and dimensioned to abut in an area between two
`stator poles of the stator assembly.
`7. A stator bobbin comprising:
`a plurality of U-shaped insulating elements configured to
`partially enclose a stator pole of a multiple pole stator
`assembly, each of said insulating elements having a first
`flange portion and a second flange portion joined by an
`intermediate web portion, the first and second flange
`portions extending along substantially an entire length
`of the intermediate web portion, each insulating ele(cid:173)
`ment being configured to substantially surround a stator
`pole. said elements interfitting to insulate a stator
`assembly.
`8. A stator insulating bobbin as in claim 7. wherein the
`second flange portion extends at an acute angle relative to
`15 the intermediate web portion.
`9. A stator insulating bobbin as in claim 7, wherein said
`intermediate web portion is configured and dimensioned to
`frictionally engage the sidewalls of a stator pole.
`10. A stator insulating bobbin as in claim 7, wherein a pair
`20 of insulating elements combine to enclose the stator pole.
`11. A stator insulating bobbin as in claim 7, wherein the
`plurality of insulating elements combine to insulate substan(cid:173)
`tially all of an interior surface of the stator assembly.
`12. In an electric motor stator assembly having a plurality
`25 of radially inwardly extending poles with flaired interfaces,
`the improvement comprising an insulated bobbin element
`configured and dimensioned to at least partially enclose both
`radially inwardly extending portions of one of said stator
`poles, the bobbin element including a first flange portion and
`30 a second flange portion joined by an intermediate web
`portion.
`13. A stator insulating bobbin element as in claim 12.
`wherein said intermediate web portion is configured and
`dimensioned to frictionally engage said radially extending
`35 portions of said stator pole.
`14. A stator insulating bobbin element as in claim 12,
`wherein a pair of insulating elements combine to enclose the
`stator pole.
`15. A stator insulating bobbin element as in claim 14,
`40 wherein tile plurality of insulating elements combine to
`insulate substantially all of an interior surface of tile stator
`assembly.
`16. A stator insulating bobbin element as in claim 12.
`wherein the insulating element is molded from a high
`45 temperature insulating material.
`17. A stator insulating bobbin element as in claim 14,
`wherein each of the insulating elements are identical.
`
`* * * * *
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