| 摘要 |
PURPOSE: To prevent vibration and simplify the structure by superimposing a magnetic flux of an electromagnetic coil on that of a permanent magnet within an air gap, synchronously driving the electromagnetic coil with voltage and strengthening the magnetic flux generated by the permanent magnet on one side of a compensating wall and weakening it on the other side alternately. CONSTITUTION: A permanent magnet 10 includes at least one partial magnet 10. 1 embedded in a compensating wall 3 within a partial area 4 and becomes magnetized in the direction of an air gap plane, thereby a simple structure is obtained. The magnetic fluxϕP of the permanent magnet 10 is divided into two partial magnetic fluxes 0.5ϕP of the same size, which are guided into an air gap 5 on both sides of the compensating wall 3 and superimposed on by an alternate magnetic fluxϕS generated on the partial magnetic fluxes of the permanent magnet from coils. Energization is made in such a way that the magnetic fluxes generating electric current on coils 6, 7 rotate in the same direction around the grooves of coil holders 8, 9 and become the same size. With this constitution, the magnetic flux is strengthened within the air gap 5 axially adjacent to the compensating wall 3, while it is weakened within the air gap 5 on the other side. This mechanism prevents sound disturbance of vibration. |
