| 摘要 |
<p>PURPOSE:To provide an inexpensive device free from imperfect insulation, and improve the reliability, by forming a projection at an outer circumference of a side wall of a U-shaped portion of a bobbin, engaging the projection with an annular groove of a main yoke member, and fixing the assembly with a resin insulator. CONSTITUTION:An outer flange 10a of a main yoke member 10 formed of an electromagnetic sheet steel is formed at its inner peripheral portion with an annular groove 10d. A side wall 11a of a sectional U-shaped resin bobbin 11 is formed at its outer periphery with a projection 11d. An excitation coil 9 is wound around the bobbin 11 to form a coil assembly, and the projection 11d of the bobbin 11 is engaged with the annular groove 10d. Then, the coil assembly of the excitation coil 9 is fixed to the main yoke member 10, and a resin insulator 15 is filled and cured between the coil assembly and the main yoke member 10. Thus, the coil assembly of the excitation coil 9 is precisely fixed at a predetermined position of the main yoke member 10 to thereby eliminate imperfect insulation, protrusion of the excitation coil 9 from the main yoke member 10, leakage of the resin insulator or the like, and ensure the high reliability.</p> |
