Method for manufacturing cylindrical members and method for manufacturing motors having the cylindrical member

摘要

A magnet (10) that is an annular member is fixed or secured on an outer circumference surface or an inner circumference surface of a yoke (4) that is a cylindrical member. An lower end surface in the axial direction of the magnet is fixed or secured to the same plane as a lower end surface in the axial direction of the yoke (4), or the lower end surface in the axial direction of the magnet is fixed or secured so as to protrude a little from the lower end surface in the axial direction of the yoke. An annular groove (4a) that is recessed outward in the radial direction or inward in the radial direction is formed on a part of the outer circumference surface or the inner circumference surface that is continuous to the yoke (4).