Brushless DC motor and brushless DC motor controller
AssigneeDaikin Industries, Ltd.
InventorKiyotaka Nishijima
Life of this patent
Estimating the term…
Abstract
A brushless DC motor has a stator and a rotor. An angle θ0 between an edge section of the flux barrier on a magnetic pole center side and an edge section on a side for coming in contact with the rib of adjacent flux barrier, with respect to the rotor center, is determined to be equal to or greater than an angle satisfying a following relationship θ0=180°*m/(Pn*f/f0) (provided 2θ0−θr<90°) wherein, a frequency of vibration which is to be reduced is represented with f, a pole pair number is represented with Pn, an electrical frequency is represented with f0=Pn*N, a motor revolution is represented with N, m=1, 3, 5, . . . , an angle of the rib with respect to the rotor center is represented with θr, therefore making of motor highly effective and decreasing of the motor acoustic noise are coped with.
Claims14
A brushless DC motor comprising:
- a stator;
- and
- a rotor comprising a plurality of permanent magnets each having a predetermined thickness and being mounted in an interior of the rotor, a plurality of flux bafflers made of non-magnetic sections, each of flux bafflers beginning from an edge section in circumferential direction of one of the permanent magnets, extending up to vicinity in a surface of the rotor, and having a length in a circumferential direction which is greater than a thickness of the permanent magnets, and a rib which is disposed between magnetic poles,
- the flux bafflers are configured and arranged such that an angle θ0 between an edge section of the flux baffler on a magnetic pole center side and an edge section on a side for coming in contact with the rib of an adjacent one of the flux bafflers, with respect to a rotor center, is determined to be equal to or greater than an angle satisfying a following relationship
- θ0=180° *m/(Pn*(f/f0)), where 2θ0−θr<90°,
- wherein, a frequency of vibration which is to be reduced is represented with f, a pole pair number is represented with Pn, an electrical frequency is represented with f0=Pn*N, a motor revolution is represented with N, m is equal to an odd number and an angle of the rib with respect to the rotor center is represented with θr.
A brushless DC motor control apparatus comprising:
- a brushless DC motor;
- and
- an inverter device which is controlled to advance a current phase with respect to an induction voltage of the brushless DC motor,
- the brushless DC motor comprising
- a stator;
- and
- a rotor comprising a plurality of permanent magnets each having a predetermined thickness and being mounted in an interior of the rotor, a plurality of flux barriers made of non-magnetic sections, each of flux barriers beginning from an edge section in circumferential direction of one of the permanent magnets, extending up to vicinity in a surface of the rotor, and having a length in a circumferential direction which is greater than a thickness of the permanent magnets, and a rib which is disposed between magnetic poles,
- the flux barriers are configured and arranged such that an angle θ0 between an edge section of the flux barrier on a magnetic pole center side and an edge section on a side for coming in contact with the rib of an adjacent one of the flux barriers, with respect to a rotor center, is determined to be equal to or greater than an angle satisfying a following relationship
- θ0180°*m/(Pn*(f/f0)), where 2θ0−θr<90°),
- wherein, a frequency of vibration which is to be reduced is represented with f, a pole pair number is represented with Pn, an electrical frequency is represented with f0=Pn*N, a motor revolution is represented with N, m is equal to an odd number and an angle of the rib with respect to the rotor center is represented with θr.
Dependencies are inferred from the claim text.