| 主权项 |
1. A permanent magnet motor, comprising:
a permanent magnet rotor mounted on a shaft having a center line defining a longitudinal axis, said rotor including an outer surface co-axial with said longitudinal axis; a stator surrounding the rotor, said stator comprising a plurality of teeth radially inwardly oriented toward the longitudinal axis, each tooth having a tooth length and a tooth tip surface geometry, wherein the plurality of teeth are distributed in a preferred asymmetric circumferential pattern with respect to an ideal inside radius of the stator based on variations in both the tooth length and the tooth tip surface geometry of each tooth, and wherein the preferred asymmetric circumferential pattern is selected using a model simulating operation of the permanent magnet motor based upon:
a plurality of motor operating points defined for the permanent magnet motor, each motor operating point including a respective motor rotational speed selected from a rotational speed operating range between a lower motor rotational speed limit and an upper motor rotational speed limit for the permanent magnet motor, a respective electrical current of the stator selected from an electrical current operating range between a lower electrical current limit and an upper electrical current limit for the permanent magnet motor and a respective control angle selected from a control angle range between a lower control angle limit and an upper control angle limit for the permanent magnet motor,a plurality of teeth combinations each comprising a plurality of teeth asymmetrically circumferentially distributed with respect to the ideal inside radius, wherein each combination comprises a different variation in both the tooth length and the tooth tip surface geometry of each tooth, andan average torque output value and a torque ripple value determined at each motor operating point for each of the teeth combinations, wherein the preferred asymmetric circumferential pattern corresponds to the teeth combination that achieves a minimum torque ripple value while achieving an average torque output that is greater than a minimum average torque output at each of the motor operating points; and an asymmetric air gap defined by a radial distance between the outer surface of the rotor and a radially inward inner surface portion of each tooth tip surface geometry, said radial distance having an asymmetric variation between minimum and maximum magnitudes based on the preferred asymmetric circumferential pattern of teeth. |
