Multi-speed motor

Claim 2

An electric motor for operation selectively at at least two different speeds, a magnetic core having a plurality of winding accepting slots; first winding means disposed in at least some of the core slots; means for selectively connecting the main winding means, in one of at least two different pole number configurations to a source of excitation voltage to thereby provide for more than one operating speed; auxiliary winding means disposed in at least some of the core slots and energizable in conjunction with the main winding means to provide a starting torque for the motor regardless of the particular pole number configuration of the main winding means, the auxiliary winding means comprising a number of coil groups defining the same number of salient polar axes, the auxiliary winding means being arranged on the core so that a first half of the coil groups are uniformly distributed on the core and a second half of the coil groups are uniformly distributed on the core, with at least two mechanically adjacent ones of the coil groups establishing instantaneous poles of opposite polarity and being separated by an arcuate distance greater than the separation between other salient polar axes of the auxiliary winding means.

Claim 3

An electric motor for operation selectively at at least two different speeds, a magnetic core having a plurality of winding accepting slots; first winding means disposed in at least some of the core slots; means for selectively connecting the main winding means, in one of at least two different pole number configurations to a source of excitation voltage to thereby provide for more than one operating speed; auxiliary winding means disposed in at least some of the core slots and energizable in conjunction with the main winding means to provide a starting torque for the motor regardless of the particular pole number configuration of the main winding means, the auxiliary winding means comprising a number of coil groups defining the same number of salient polar axes, the auxiliary winding means being arranged on the core so that a first half of the coil groups are uniformly distributed on the core and a second half of the coil groups are uniformly distributed on the core, with at least two mechanically adjacent ones of the coil groups establishing instantaneous poles of opposite polarity and being separated by an arcuate distance greater than the separation between other salient polar axes of the auxiliary winding means.

Claim 4

An electric motor for operation selectively at at least two different speeds, a magnetic core having a plurality of winding accepting slots; first winding means disposed in at least some of the core slots; means for selectively connecting the main winding means, in one of at least two different pole number configurations to a source of excitation voltage to thereby provide for more than one operating speed; auxiliary winding means disposed in at least some of the core slots and energizable in conjunction with the main winding means to provide a starting torque for the motor regardless of the particular pole number configuration of the main winding means, the auxiliary winding means comprising a number of coil groups defining the same number of salient polar axes, the auxiliary winding means being arranged on the core so that a first half of the coil groups are uniformly distributed on the core and a second half of the coil groups are uniformly distributed on the core, with at least two mechanically adjacent ones of the coil groups establishing instantaneous poles of opposite polarity and being separated by an arcuate distance greater than the separation between other salient polar axes of the auxiliary winding means.

Claim 5

The invention of claim 1 wherein the interconnected coil groups are adapted to be connected to a source of alternating current for both starting and running operation of the motor.

Claim 6

The invention of claim 1 wherein the auxiliary winding means comprises a number of interconnected coil groups, each coil group forming at least one magnetic pole during operation, with each one of a pair of electrically adjacent coil groups being mechanically separated from one another by at least one other coil group.

Claim 7

The invention of claim 3 wherein there are an even number L of interconnected coil groups in the auxiliary winding means, L/2 electrically adjacent coil groups are arranged on the magnetic core to simultaneously provide magnetic poles of a first magnetic polarity, the remaining L/2 coil groups are arranged on the magnetic core to simultaneously provide poles of a magnetic polarity opposite to the first magnetic polarity, and the coil groups are mechanically interleaved around the core to provide mechanically adjacent alternate magnetic poles.

Claim 8

The invention of claim 1 wherein the first winding means comprises a first even number N of interconnected coil groups, with the N coil groups forming running poles for high speed operation and a second even number M of interconnected coil groups with the M coil groups forming running poles for low speed operation; the auxiliary winding means comprises a third even number L of interconnected coil groups with the L coil groups forming auxiliary poles where M > N > or = L; and further comprising means for connecting the L interconnected coil groups across a source of alternating current and means for selectively connecting only one of the N and M coil groups across a source of alternating current for a desired speed of operation.

Claim 9

The invention of claim 5 further comprising means for connecting one-half of the L coil groups to a source of alternating current whereby each of the connected one-half coil groups will establish poles of the same instantaneous magnetic polarity so aS to provide one-half direct poles and one-half consequent poles, and an intermediate speed of operation.

Claim 10

The invention of claim 5 where L is the greatest common divisor of M and N.

Claim 11

A pole changing electric motor comprising: a stator core having a rotor accepting bore and a plurality of generally radially extending winding accommodating slots; a rotor supported for rotation within the stator bore; a first main winding disposed in at least some of the core slots and operable to provide a number N of magnetic poles when connected to a source of alternating current; a second main winding disposed in at least some of the core slots and operable to provide a number M of magnetic poles when connected to a source of alternating current, where M is greater than N; an auxiliary winding comprising a number of coil groups disposed in at least some of the core slots and operable to provide at least a number L of auxiliary magnetic poles when connected to a source of alternating current, the auxiliary winding having a tap connection therein to allow the optional connection of a portion only of the auxiliary winding to a source of alternating current to thereby optionally provide at least only L/2 auxiliary magnetic poles; the numbers M, N, and L being whole numbers with L N; said first main winding comprising N coil groups, said second main winding comprising M coil groups, and said auxiliary winding comprising L coil groups; and at least L/2 poles being instantaneously of like magnetic polarity whereby L/2 consequent auxiliary poles may be established when the tap connection is connected to a source of power.

Claim 12

A pole changing electric motor comprising: a stator core having a rotor accepting bore and a plurality of generally radially extending winding accommodating slots; a rotor supported for rotation within the stator bore; a first main winding disposed in at least some of the core slots and operable to provide a number N of magnetic poles when connected to a source of alternating current; a second main winding disposed in at least some of the core slots and operable to provide a number M of magnetic poles when connected to a source of alternating current, where M is greater than N; an auxiliary winding comprising a number of coil groups disposed in at least some of the core slots and operable to provide at least a number L of auxiliary magnetic poles when connected to a source of alternating current, the auxiliary winding having a tap connection therein to allow the optional connection of a portion only of the auxiliary winding to a source of alternating current to thereby optionally provide at least only L/2 auxiliary magnetic poles; the numbers M, N, and L being whole numbers with L N; said first main winding comprising N coil groups, said second main winding comprising M coil groups, and said auxiliary winding comprising L coil groups; and at least L/2 poles being instantaneously of like magnetic polarity whereby L/2 consequent auxiliary poles may be established when the tap connection is connected to a source of power.

Claim 13

The motor of claim 8 wherein the auxiliary winding is disposed in the core slots to provide a nonuniformly distributed set of L salient auxiliary poles of alternating instantaneous magnetic polarity when the entire auxiliary winding is connected to a source of alternating current.