| 摘要 |
PURPOSE:To eliminate fluctuation of commutation timing due to load current by detecting the rotary position of a rotor based on detection of sinusoidal gap formed between a fixed member and a rotary member. CONSTITUTION:An approximately annular rotary member 11 is fixed to a tubular yoke 1 constituting an outer rotor. Furthermore, a fixed disc member 12 is fixed to the supporting shaft 8 of an inner stator 6 and two gap sensors 9a, 9b are fixed with 9d electric angle to the circumferential face of the fixed member 12. The inner face of the rotary member 11 is waved, and when the rotary member 11 rotates together with the yoke 1 the length of gap between the end face of the gap sensor 9 and the inner face of the rotary member 11 varies sinusoidally. Consequently, when one is Sintheta the other is Costheta. Sintheta and Costheta output waves from the gap sensors 9a, 9b and phase control amount alphaare fed to a three-phase commutation signal generating circuit 16 and three- phase commutation signal shown by the formula is produced. |
