| 摘要 |
PURPOSE:To obtain a motor wherein no torque ripples are generated by supplying currents which are proportional to sin<2>theta and cos<2>theta to 2-phase driving coils by brushes and commutators, with the currents being changed at a zero level. CONSTITUTION:An armature 5 having 2-phase driving coils 6 and 7 is rotatably provided so as to oppose, e.g., 8-pole-field magnetis having magnetic-flux distribution of a trapezoidal waveform in magnetizing saturation. Position magnets 12 are provided so that they are rotated together with said armature 5. Then, currents I1 and I2 which are proportional to sin<2>theta and cos<2>theta (theta is a rotation angle) are formed, based on the output of a magnetic sensing element 13 which senses the field of the position magnets 12. Then, said currents I1 and I2 are supplied to the driving coils 6 and 7, by a brush 8 and a commutator 9, and by a brush 10 and a commutator 11. Said brushes and commutators are connected in a specified way, respectively. The direction of the currents I1 and I2 which flow in the driving coils 6 and 7 are changed in response to the change in the magnetic fields and at the point when the current becomes a zero level. |
