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Publication numberUS3668585 A
Publication typeGrant
Publication dateJun 6, 1972
Filing dateMar 1, 1971
Priority dateMar 1, 1971
Publication numberUS 3668585 A, US 3668585A, US-A-3668585, US3668585 A, US3668585A
InventorsHoward R Johnson
Original AssigneeKelsey Hayes Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electromagnetic device with cast magnetic path
US 3668585 A
Abstract
An electromagnetic device utilizing a coil and having a cast magnetic path around the coil and a method of manufacture.
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Description  (OCR text may contain errors)

Unified States Patent Johnson 1 June 6, 1972 [541 ELECTROMAGNETIC DEVICE WITH [56] References cm CAST I'MGNETIC PATH UNITED sTATEs PATENTS [72] Invent 2,387,073 10/1945 Horlacher ..310/44 ux [73] Assignee: Kelsey-Hayes Company, Romulus, Mich. 3,255,512 6/1966 Lochner ..310/44 [22] Filed: Man I 1971 3,325,760 6/1967 Bernard ..336/83 x [21] A15 PL No; 119,951 FOREIGN PATENTS 0R APPLICATIONS 73 ,9 0 s 19 6 G ..310 2 Related US. Application Data 7 9 3 many ,4

[63] Continuation of Ser. No. 817,655, Apr. 21, 1969, m 'w Goldberg abandoned.

, I 57 ABSTRACT [52] US. Cl ..336/83, 310/42 An electromagnetic device utilizing a co and having a cast Int. Cl .110" 15/02 magnetic path around thg co" and a method of manufacture Field of Search ..3 10/42, 43, 44, 254; 336/83 4 Claims, 5 Drawing Figures ELECTROMAGNETIC DEVICE WITH CAST MAGNETIC SUMMARY BACKGROUND OF THE INVENTION or at least is minimal. Therefore it is an object of the present invention to provide a new and improved coil assembly conitruction and method for electrical apparatus.

The present construction has been found to be particularly useful in the construction of electrical generating devices used as speed sensors j for skid control systems. Therefore it is another object toprovide a novel coil assembly construction and method for use in electrical generating devices.

FIG. 1 is a side elevational view of a coil and bobbin assembly for use in the .present invention;

FIG. 2 is a partial sectional view of the assembly of FIG. 1 taken substantially along the lines 2-2;

FIG. 3 is a view of the assembly of FIG; 1 taken generally in the direction of lines 33;

FIG. 4 is a view depictingthe formation of the cast magnetic path around the coil and bobbin assembly; and

FIG. 5 is a pictorial, exploded view of the final formed coil assembly in a generator assembly. I

Looking now to FIGS. 1-3 a coil and bobbin assembly in cludes a plastic, annularbobbin 12 having an annular, radially outer channel 14 and a coil 16 circumferentially woundin the channel 14. The channel 14 is defined by a pair of radially outwardly extending flanges 18 and 20fand an annular ring portion 22. The ring portion 22 has a first plurality of axially extending grooves 24 (extending from the flange 20) and a second set of axially extending grooves 26 (extending from flange 18). Grooves 24 and 26 are located alternately relative to each other around the circumference of the ring portion 22.

Next the structure for the magnetic path is cast around the coil and bobbin assembly 10 in the manner shown in FIG. 4. The assembly 10 is located in a die 28 (diagrammatically shown) with the die '28 including a spindle 30 on which the radially inner surface of the ring portion 22 of the bobbin 12 closely nests. The remainder of the die 28 defines a housing 32 which is spaced from the remaining portion of the coil and bobbin assembly 10. Next a mixture of ferro magnetic powders and a resin carrier is injected into the die 28 to fill the spaces remaining around the coil and bobbin assembly 10including the grooves 24 and 26. It has been found that a mixture of 86 percent spherical ferro' (iron) powder and 14 percent resin provides a satisfactory construction. The high concentration of iron is desirable to provide good magnetic structure 34which substantially completely encircles the coil and bobbin assembly 10 and provides a good magnetic path around the coil 16. As shown in FIG. 5, the coil and bobbin assembly l0 and cast structure 34 comprise a stator assembly 36 which is used with a rotor assembly 38. The rotor assembly38 is concentric with stator assembly 36 and includes a plurality of magnets 40 located circumferentially such that one magnet is in radial alignment with each of the fingers 24a and 26a (defined by that portion of magnetic structure 34 located in bobbin grooves 24 and 26). Alternate ones of magnets 40 are of opposite polarity. Thus on rotation of rotor assembly 38 such that the north poles of magnets 40 are in line with fingers 24a and south poles are in line with fingers 26a flux will travel in one direction through structure 34 around coil 16; upon further rotation the north poles will be in line with fingers 26a and south poles will be in line with fingers 24a resulting in flux traveling in the opposite direction through structure 34 around coil 16. The alternate flux reversals around coil 16 through magnetic structure 34 will result in an alternating current being generated in coil 16. The result is an inexpensive stator assembly 36 having good electrical characteristics.

While the structure and method of the present invention have been shown and described in conjunction with a stator construction, features of the invention are applicable to other electromagnetic devices.

' While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the invention.

I claim:

1. A stator for an assembly of a rotor and stator comprising: an annular bobbin of high reluctance material having a plurality of grooves located to confront said rotor and defining spaced bobbin projections with each projection having a surface confronting said rotor, a coil wound on said bobbin, and a unitary integral structure comprising a composition of powdered material generally having a low reluctance and a bonding agent for said powdered material, said unitary structure being cast around said bobbin and said coil so as to at least partially encapsulate said'bobbin and said coil to define a magnetic path about said coil, being cast in said grooves so as to substantially completely fill said grooves to define a plurality of fingers with each finger having a surface confronting said rotor, being cast to define path means which magnetically 2. The stator of claim 1 with alternate ones of said fingers defining magnetic paths in opposite directions around said coil. 7

3. The stator of claim 1 with said powdered material comprising a high ratio of iron powders.

4. A stator for an assembly of a rotor and stator comprising: an annular bobbin of high reluctance material having a plurality of grooves located to confront said rotor and defining spaced bobbin projections with each projection having a surface confronting said rotor, a coil wound on said bobbin, and a unitary integral structure comprising a composition of powdered material generally having a low reluctance and a bonding agent for said powdered material, said unitary structure being cast around said bobbin and said coil so as to at least partially encapsulate said bobbin and said coil to define a magnetic path about said coil, being cast in said grooves so as to substantially completely fill said grooves to define a plurality of fingers with each finger having a surface confronting said rotor and pair of ends, being cast to define path means which magnetically connects one end of each of said fingers to said magnetic path about said coil, and being cast to provide smooth and continuous surface confronting said rotor comprising said surfaces of said bobbin projections confronting said rotor and said surfaces of said fingers confronting said rotor, said bobbin including a portion adjacent the other end of each of said fingers so as to interpose a high reluctance between said other end of each of said fingers and said magnetic path about said coil.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2387073 *Oct 8, 1943Oct 16, 1945Clare & Co C PRotor for electric motors
US3255512 *Aug 17, 1962Jun 14, 1966Trident Engineering AssociatesMolding a ferromagnetic casing upon an electrical component
US3325760 *Oct 1, 1965Jun 13, 1967Gen Motors CorpElectromagnet with resinous ferromagnetic cladding
DE737990C *Aug 18, 1936Jul 30, 1943AegSynchronkleinmotor
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4009406 *Nov 25, 1975Feb 22, 1977Tokuzo InaribaSynchronous micromotor with a permanent magnet rotor
US4100520 *Jul 22, 1975Jul 11, 1978Ben-Gurion University Of The Negev Research And Development AuthorityDevices for controlling A.C. motors
US4132910 *Nov 11, 1976Jan 2, 1979Muanyagipari Kutato IntezetLinearly moving or rotated flat armature for motor and pulling magnets
US4334166 *Feb 19, 1980Jun 8, 1982Kanto Kasei Kogyo Kabushiki KaishaRotary magnetic sensor
US4446461 *Nov 2, 1981May 1, 1984United Technologies CorporationInstrumentation for a rotary machine
US6833639 *Dec 23, 2002Dec 21, 2004Cyber Industrial Ltd.Electric actuator
US7300615 *Jan 12, 2005Nov 27, 2007Sandia CorporationHigh frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials
Classifications
U.S. Classification336/83, 310/44, 310/257, 310/216.66, 310/49.13, 310/156.38
International ClassificationH02K21/14, H02K1/14
Cooperative ClassificationH02K1/145, H02K21/145, H02K2201/12
European ClassificationH02K21/14C, H02K1/14C
Legal Events
DateCodeEventDescription
Jun 1, 1990ASAssignment
Owner name: CHEMICAL BANK, NEW YORK
Free format text: SECURITY INTEREST;ASSIGNOR:KELSEY-HAYES COMPANY;REEL/FRAME:005317/0549
Effective date: 19891129
Jul 21, 1989ASAssignment
Owner name: IBJ SCHRODER BANK & TRUST COMPANY, NEW YORK
Free format text: SECURITY INTEREST;ASSIGNOR:KELSEY-HAYES COMPANY;REEL/FRAME:005284/0027
Effective date: 19941114