Low torque ripple switched reluctance motor

Claim 2

A switched reluctance motor comprising: an annular stator defining a plurality of radially-inwardly-extending poles, each stator pole defining a first shape in radial cross-section characterized by a generally rectangular body portion having substantially parallel sides, and a tapered tip portion with a radially-innermost arcuate surface, wherein the angle at which the sides of the tip portion taper is at least about 30° but is no greater than about 40° relative to the sides of the rectangular body portion, and wherein a nominal dimension from side to side of each pole's rectangular body portion is between about 1.3 times and about 1.45 times a nominal chordal dimension across the tip portion's radially-innermost arcuate surface; and a rotor, supported for rotation within said stator, defining a plurality of radially-outwardly-extending poles, each rotor pole defining a second shape in radial cross section.

Claim 3

The motor of claim 1, wherein the first shape of each stator pole is further characterized in that the sides of the rectangular body portion extend generally parallel to a radial line bisecting the stator pole.

Claim 4

The motor of claim 1, wherein the first shape of each stator pole is further characterized in that the radially-innermost surface of the tip portion is centered about a radial line bisecting the stator pole.

Claim 5

The motor of claim 2, wherein the first shape of each stator pole is symmetrical about the radial line bisecting the stator pole.

Claim 6

The motor of claim 1, wherein the second shape of each rotor pole has an arcuate radially-outermost surface having a nominal chordal dimension slightly greater than the nominal chordal dimension across the radially-innermost arcuate surface of the tip portion of each stator pole.

Claim 7

A switched reluctance motor comprising: an annular stator defining a plurality of radially-inwardly-extending poles, each stator pole defining a first shape in radial cross-section characterized by a generally rectangular body portion having substantially parallel sides, and a tapered tip portion with a radially-innermost arcuate surface, wherein the angle at which the sides of the tip portion taper is at least about 30° but is no greater than about 40° relative to the sides of the rectangular body portion, and wherein a nominal dimension from side to side of each pole's rectangular body portion is between about 1.3 times and about 1.45 times a nominal chordal dimension across the tip portion's radially-innermost arcuate surface; a plurality of windings disposed about said stator poles wherein windings associated with diametrically opposing stator poles are electrically connected to define a respective motor phase; and a rotor, supported for rotation within said stator, defining a plurality of radially-outwardly-extending poles, each rotor pole defining a second shape in radial cross section.

Claim 8

A switched reluctance motor comprising: an annular stator defining a plurality of radially-inwardly-extending poles, each stator pole defining a first shape in radial cross-section characterized by a generally rectangular body portion having substantially parallel sides, and a tapered tip portion with a radially-innermost arcuate surface, wherein the angle at which the sides of the tip portion taper is at least about 30° but is no greater than about 40° relative to the sides of the rectangular body portion, and wherein a nominal dimension from side to side of each pole's rectangular body portion is between about 1.3 times and about 1.45 times a nominal chordal dimension across the tip portion's radially-innermost arcuate surface; a plurality of windings disposed about said stator poles wherein windings associated with diametrically opposing stator poles are electrically connected to define a respective motor phase; and a rotor, supported for rotation within said stator, defining a plurality of radially-outwardly-extending poles, each rotor pole defining a second shape in radial cross section.

Claim 9

The motor of claim 6 wherein the stator is of laminated construction.

Claim 10

The motor of claim 6, wherein the second shape of each rotor pole has an arcuate radially-outermost surface having a nominal chordal dimension slightly greater than the nominal chordal dimension across the radially-innermost arcuate surface of the tip portion of each stator pole.

Claim 11

A switched reluctance motor comprising: an annular stator defining a plurality of radially-inwardly-extending poles extending along a longitudinal axis, each stator pole defining a first shape in radial cross-section characterized by a generally rectangular body portion having substantially parallel sides, and a tapered tip portion extending the longitudinal length of said stator with a radially-innermost arcuate surface, wherein the angle at which the sides of the tip portion taper is at least about 30° but is no greater than about 40° relative to the sides of the rectangular body portion, and wherein a nominal dimension from side to side of each pole's rectangular body portion is between about 1.3 times and about 1.45 times a nominal chordal dimension across the tip portion's radially-innermost arcuate surface; a plurality of windings disposed about said stator poles wherein windings associated with diametrically opposing stator poles are electrically connected to define a respective motor phase; and, a rotor, supported for rotation within said stator, defining a plurality of radially-outwardly-extending poles, each rotor pole defining a second shape in radial cross section.

Claim 12

A switched reluctance motor comprising: an annular stator defining a plurality of radially-inwardly-extending poles extending along a longitudinal axis, each stator pole defining a first shape in radial cross-section characterized by a generally rectangular body portion having substantially parallel sides, and a tapered tip portion extending the longitudinal length of said stator with a radially-innermost arcuate surface, wherein the angle at which the sides of the tip portion taper is at least about 30° but is no greater than about 40° relative to the sides of the rectangular body portion, and wherein a nominal dimension from side to side of each pole's rectangular body portion is between about 1.3 times and about 1.45 times a nominal chordal dimension across the tip portion's radially-innermost arcuate surface; a plurality of windings disposed about said stator poles wherein windings associated with diametrically opposing stator poles are electrically connected to define a respective motor phase; and, a rotor, supported for rotation within said stator, defining a plurality of radially-outwardly-extending poles, each rotor pole defining a second shape in radial cross section.

Claim 13

The motor of claim 9 wherein the stator is of laminated construction.

Claim 14

The motor of claim 9 wherein the second shape of each rotor pole has an arcuate radially-outermost surface having a nominal chordal dimension slightly greater than the nominal chordal dimension across the radially-innermost arcuate surface of the tip portion of each stator pole.