System for reducing bearing currents in an electric machine
AssigneeGM Global Technology Operations LLC
InventorsWilliam T. Ivan, Alireza Fatemi, Rajeev Vyas
Life of this patent
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Abstract
An electric machine including a stator, a rotor within the stator, and a shaft to which the rotor is mounted. The shaft extends through the stator. A first bearing and a second bearing support the shaft within the stator to allow the shaft and the rotor to rotate within the stator. The rotor is between the first bearing and the second bearing. A first magnetic core is at the shaft between the rotor and the first bearing. The first magnetic core is configured to suppress a bearing current flowing across the shaft, the first bearing, and the second bearing.
Claims20
An electric machine comprising:
- a stator;
- a rotor within the stator;
- a shaft to which the rotor is mounted, the shaft extending through the stator;
- a first bearing and a second bearing supporting the shaft within the stator to allow the shaft and the rotor to rotate within the stator, the rotor is between the first bearing and the second bearing;
- a first magnetic core at the shaft between the rotor and the first bearing, the first magnetic core configured to suppress a bearing current flowing across the shaft, the first bearing, and the second bearing;
- and
- an electromagnetic interference (EMI) shield between the first magnetic core and end windings of the stator.
An electric machine comprising:
- a stator;
- a rotor within the stator;
- a shaft to which the rotor is mounted, the shaft extending through the stator;
- a first bearing and a second bearing supporting the shaft within the stator to allow the shaft and the rotor to rotate within the stator, the rotor is between the first bearing and the second bearing;
- a first magnetic core at the shaft between the rotor and the first bearing, the first magnetic core configured to suppress a bearing current flowing across the shaft, the first bearing, and the second bearing;
- a first electromagnetic interference (EMI) shield between the first magnetic core and end windings of the stator;
- a second magnetic core at the shaft between the rotor and the second bearing, the second magnetic core configured to suppress the bearing current;
- and
- a second EMI shield between the second magnetic core and the end windings of the stator;
- wherein the electric machine is operable as a motor and a generator.
An electric machine comprising:
- a stator including end windings extending axially outward at opposite axial ends of the stator;
- a rotor within the stator;
- a shaft to which the rotor is mounted, the shaft extending through the stator;
- a first bearing and a second bearing supporting the shaft within the stator to allow the shaft and the rotor to rotate within the stator, the rotor is between the first bearing and the second bearing;
- a first magnetic core at the shaft between the rotor and the first bearing, the first magnetic core is closer to the first bearing than the rotor, is surrounded by the end windings of the stator, and is configured to suppress a bearing current flowing across the shaft, the first bearing, and the second bearing;
- a first electromagnetic interference (EMI) shield between the first magnetic core and end windings of the stator;
- a second magnetic core at the shaft between the rotor and the second bearing, the second magnetic core is closer to the second bearing than the rotor, is surrounded by the end windings of the stator, and is configured to suppress the bearing current;
- and
- a second EMI shield between the second magnetic core and the end windings of the stator;
- wherein the electric machine is operable as a motor and a generator.
Dependencies are inferred from the claim text.