EP0504093A1
Expired / Lapsed
EP
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Isolated segmental switch reluctance motor
Assignee: Emerson Electric Co
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Filing: 1992-03-05
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Granted: —
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Expires: 2012-03-05
Abstract
Abstract A switched reluctance motor has a stator with a plurality of salient motor poles disposed about a central bore. A rotor having an even number of rotor poles is disposed for rotation in the central bore. Magnetizing phase windings are associated with the stator poles for selectively generating magnetic fields which extend from the stator poles into the central bore and define an even number of phases. The windings are disposed such that each stator pole is adjacent two phase windings of opposite polarity with the magnetic flux through each stator varying in direction with the energization of the various phases. The rotor includes a plurality of rotor segments disposed about the periphery of the rotor. Each segment is magnetically active and defines a pair of spaced rotor poles. The spacing between rotor poles for a given rotor segment is substantially the same as that between adjacent stator poles. The rotor further includes non-magnetic material disposed between the rotor segments to magnetically isolate one rotor segment from another so magnetic flux between an adjacent pair of stator poles only passes through the nearest rotor segment. The non-magnetic material provides structural integrity to the rotor and holds the rotor segments fixedly in place.
Inventors
- 👤 Gary Edward Horst
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 14:05
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/24; H02K1/246; H02K19/00; H02K19/02; H02K19/10; H02K19/103; H02K29/00; H02K29/03; H02K3/00; H02K3/04; H02K3/28; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
205 words
A switched reluctance motor having a stator with a plurality of salient motor poles disposed about a central bore, a rotor having an even number of rotor poles and disposed for rotation in the central bore, and magnetizing phase windings associated with the stator poles for selectively generating magnetic fields extending from the stator poles into the central bore and defining an even number of phases, wherein the windings are disposed such that each stator pole is adjacent two phase windings of opposite polarity with the magnetic flux through each stator varying in direction with the energization of the various phases, and the rotor includes a plurality of rotor segments disposed about the periphery of the rotor with each segment being magnetically active and defining a pair of spaced rotor poles with the spacing between rotor poles of a given rotor segment being substantially the same as that between adjacent stator poles, the rotor further including non-magnetic material disposed between the rotor segments to magnetically isolate one rotor segment from another so magnetic flux between an adjacent pair of stator poles only passes through the nearest rotor segment, the non-magnetic material providing structural integrity to the rotor and holding the rotor segments fixedly in place.
Claim 2
Dependent Claim
29 words
The motor of claim 1 wherein the rotor comprises a rotor assembly including a frame formed of a non-magnetic material in which the magnetically active rotor segments are installed.
Claim 3
Dependent Claim
27 words
The motor of claim 2 wherein each segment defining a rotor pole is comprised of plates of magnetic material stacked together to form a laminate pole structure.
Claim 4
Dependent Claim
38 words
The motor of claim 3 where the stacks of plates are disposable in a mold in a spaced relationship from each other with the non-magnetic material set in the mold about the stacks to form the resultant frame.
Claim 5
Dependent Claim
19 words
The motor of claim 3 wherein the plates are half blanked plates which are substantially identical to each other.
Claim 6
Dependent Claim
19 words
The motor of claim 5 wherein each plate has a generally trapezoidal shape with curved inner and outer faces.
Claim 7
Dependent Claim
35 words
The motor of claim 6 wherein the frame includes means for precisely positioning the stacks of plates about the periphery of the frame whereby the rotor poles have the proper electrical spacing from each other.
Claim 8
Dependent Claim
48 words
The motor of claim 7 wherein the plates have a V-shaped inner section and each portion of the frame adjacent the inner end of the plates have recesses in which the legs forming the V's fit thereby to align the stacks of plates with respect to each other.
Claim 9
Dependent Claim
16 words
The motor of claim 7 further including means for retaining the stacks of plates in place.
Claim 10
Dependent Claim
46 words
The motor of claim 9 wherein an inset is formed at one end on the outer face of each plate and the frame has an arm extending about the outer face of each plate over the insets, the arm locking the stack of plates in place.
Claim 11
Dependent Claim
34 words
The motor of claim 9 wherein each plate has a notch formed in its outer margin intermediate the ends of the plate, the notch serving to form an increased air gap between the rotor.
Claim 12
Dependent Claim
26 words
The motor of claim 11 wherein the depth of the notch is a minimum of three times the normal air gap between the rotor and stator.
Claim 13
Dependent Claim
23 words
The motor of claim 1 wherein the poles in the stator define teeth therebetween and each magnetizing phase winding spans two stator teeth.
Claim 14
Dependent Claim
10 words
The motor of claim 1 which is a unidirectional motor.
Claim 15
Dependent Claim
10 words
The motor of claim 14 which is a 2-phase motor.
Claim 16
Dependent Claim
19 words
The motor of claim 15 wherein the stator and rotor each has an even, and equal, number of poles.
Claim 17
Dependent Claim
14 words
The motor of claim 1 wherein the plates are formed of a ferromagnetic material.
Claim 18
Dependent Claim
11 words
The motor of claim 1 wherein the non-magnetic material is aluminum.
Claim 19
Independent Claim
151 words
A method of constructing a switched reluctance motor comprising: stamping laminations for rotor segments from a magnetic material, the laminations being substantially identical; stacking the laminations into an even number of rotor segment stacks, each stack being the same height and shape, and each stack being physically separated from each other; permanently affixing the rotor segment stacks in place to form the rotor of the motor by molding a non-magnetic material about the stacks, the non-magnetic material functioning to magnetically isolate the stacks from each other; providing a toothed stator for the motor, the stator having an even number of teeth defining an even number of stator slots, and the stator defining a central bore for the motor; inserting an even number of phase windings between the stator teeth with adjacent stator slots containing phase windings of opposite polarity; and, inserting the rotor into the central bore defined by the stator.
Claim 20
Dependent Claim
54 words
The method of claim 17 further including forming a notch in the outer face of the stacks of laminations to provide an air gap between the stator and rotor greater than the normal air gap therebetween, the depth of the notch being a minimum of three times the width of the normal air gap.
References Cited (Backward Citations)
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