US 5,306,972 A · AC motor system

Abstract

An alternating current (AC) motor system includes an AC motor having a rotor and a stator with the rotor having a plurality of air passes for passing cooling air and the stator having end windings extending from each end. An air deflector is coupled to one end of the rotor and has a generally curved configuration for directing cooling air exiting the air passages into a generally radial flow direction and onto the stator end windings. The stator end windings comprise turns of a plurality of electrical conductors forming the stator winding circuits which are wound to form a plurality of phase windings. Controllable switches are connected to the winding circuits for coupling the phase windings into either a parallel or series circuit arrangement. The system is responsive to motor speed and operating state for selectively switching the windings between the series and parallel electrical circuit arrangements. Resistors are coupled in series electrical circuit with each of the electrical phase windings and controllable switches are coupled in parallel with the resistors for selectively bypassing phase current around the resistors.

Claims25

Dependent claims

An alternating current (AC) motor system comprising:

an AC induction motor having a rotor and a stator, the rotor including a rotor winding comprising rotor bars passing through a core and having bar extensions extending beyond each end of the core, ends of the rotor bar extensions being connected together by end rings, the rotor bar extensions and end rings comprising end turns of the rotor winding, the rotor still further including a plurality of radial air passages formed between the rotor bar extensions, the end rings and the ends of the core for passing cooling air from one end to another end of the rotor, the stator having end windings extending from each end thereof;
and
air deflector means coupled to said another end of said rotor generally overlaying said air passages exiting from said another end, said deflector means having a generally curved configuration on a surface facing at least some of said air passages for directing cooling air exiting said passages into a generally radial flow direction and onto and through said end turns of said rotor and then onto said stator end windings adjacent said another end of said rotor.

An alternating current (AC) motor system comprising:

an AC motor having a rotor and a stator, said stator having a plurality of electrical conductors forming a preselected number of electrical winding circuits;
first controllable electrical switching means coupled in circuit with said winding circuits, said switching means being operable to selectively couple said winding circuits into at least two different electrical configurations, each of said configurations having the same number of electrical phases;
means responsive to speed of said motor for selectively switching said windings between said configurations, one of said configurations comprising a relatively low speed, relatively high inductance configuration and the other one of said configurations comprising a relatively high speed, relatively low inductance configuration, said motor being operable in either of said configurations during steady-state operation;
resistor means coupled in series electrical circuit with each of said electrical phases;
second controllable switching means coupled in parallel electrical circuit with said resistor means for selectively bypassing current about said resistor means;
and
means responsive to operation of said motor in a regenerative electrical mode for energizing said second switching means for forcing current through said resistor means.

4 more elements

An alternating current (AC) motor system comprising:

an AC induction motor having a rotor and a stator, the rotor including a rotor winding comprising rotor bars passing through a core and having bar extensions extending beyond each end of the core, ends of the rotor bar extensions being connected together by end rings, the rotor bar extensions and end rings comprising end turns of the rotor winding, the rotor still further including a plurality of radial air passages formed between the rotor bar extensions, the end rings and the ends of the core for passing cooling air from one end to another end of the rotor, the stator having end windings extending from each end thereof, said end windings comprising end turns of a plurality of electrical conductors forming stator winding circuits arranged in a plurality of electrical phase windings;
air deflector means coupled to said another end of said rotor generally overlaying at least some of said air passages exiting from said another end, said deflector means having a generally curved configuration on a surface facing said at least some air passages for directing cooling air exiting said passages into a generally radial flow direction and onto and through said end turns of said rotor and then onto said stator end windings adjacent said another end of said rotor;
and
resistor means selectively coupled in series circuit with each of said phase windings.

1 more element

Dependencies are inferred from the claim text.

AC motor system

Life of this patent

AC motor system

Life of this patent

Abstract

Claims25