SMALL ELECTRONIC DRIVE UNIT, SOFT-MAGNETIC MAGNETIC FEEDBACK CIRCUIT UNIT, AND METHOD OF MANUFACTURING SOFT-MAGNETIC MAGNETIC FEEDBACK CIRCUIT UNIT

摘要

PROBLEM TO BE SOLVED: To improve a small electronic drive unit in which optimized magnetic characteristics achieves low loss, and a laminated magnetic feedback unit.SOLUTION: The present invention provides a small electrical drive unit 1 like a rotational field drive unit that is excited with a permanent magnet. The small electrical drive unit includes: a stator 2 having a stator winding 8; a soft-magnetic magnetic feedback circuit unit 6 cylindrically surrounding the stator winding 8 of the stator 2 and having a plurality of sheet-shaped metallic laminated boards 22 in a circular plate form laminated in layers for forming a cylindrically laminated magnetic core 20; and a rotor 4 disposed inside the stator 2. The plurality of sheet-shaped metallic laminated boards 22 at the laminated magnetic core 20 are held by the application of prestress in a radial direction with a force fit in a supporting sleeve 24 that surrounds the plurality of sheet-shaped metallic laminated boards 22 on the same axis, and are held by the application of the prestress in a jointed state in an axial direction without adhesion means or integration joint means.SELECTED DRAWING: Figure 2