| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotor for rotary machine which can reduce torque ripple or cogging torque.SOLUTION: Since the outer magnetic body area 23 is formed so that the permeability changes gradually in the circumferential direction from a bridge 22, magnetic flux density distribution of the outer magnetic body area 23 can be changed in arbitrary shape in the circumferential direction. For example, magnetic flux density distribution in the circumferential direction can be made sinusoidal, by increasing the magnetic flux density in the pole central part in the circumferential direction of the outer magnetic body area 23, and decreasing the inter-pole magnetic flux density in the circumferential direction. Since the fifth-order and seventh-order components are never contained in the magnetic flux density distribution, torque ripple of sixth-order is not generated, and generation of sound or vibration can be suppressed. |
