| 摘要 |
Method for making a rotor assembly for a stepping motor is provided by locating one flat side of a brittle magnetic rotor annulus against a preformed annular alignment surface molded into a thermoplastic hub and then thermoplastically working localized portions of the hub adjacent the other flat side of the rotor to form in situ a second annular shoulder thereagainst to lock the rotor in the aligned position. Other localized portions of the hub are thermoplastically worked to form in situ an inner circumferential lip extending radially from the hub into a corresponding groove in the shaft supporting the hub, thereby preventing axial movement of the hub and rotor mounted thereon. Required alignment of the brittle rotor disc is thereby achieved while minimizing the danger of breakage and also minimizing the number of components and assembly steps. |
