Patent ID: 8074344
Filing Date: 2011-12-13
Classification: H02K,Y10T

Abstract:
1. A method of manufacturing a rotor holder of a motor, the method comprising: (a) performing a test to predetermine an imbalance of a rotor holder having a top plate portion and a side wall portion; (b) subsequently forming a top plate portion having a substantially discoid shape substantially centered about a central axis, and a side wall portion extending in a direction substantially parallel to the central axis from the outer periphery of the top plate portion by feeding a metal plate in a predetermined direction and shaping the metal plate with a die; and (c) using the die, punching a hole through the metal plate, of dimensions and at a location based on an outcome of the test, before said shaping of the metal plate is completed such that when the side wall portion is formed, the hole constitutes a punched part of the side wall portion.