| 摘要 |
PURPOSE:To prevent a trouble of a DC micromotor due to graphitization by dividing the end of a brush into a plurality of pieces to raise a pattern continued by a noble metal layer, and displacing the pattern from the adjacent noble metal at a half period, thereby preventing the contacting area of a commutator from varying. CONSTITUTION:A brush 3 which flows a current in contact with a commutator is composed with a substrate 1 made of an elastic material and a contact unit 2 which is divided into a plurality (3 in the drawing). The unit 2 is formed by pressing and raising a noble metal layer 2a of Ag-Pd alloy or the like in the thickness of approx. 0.01mm., and the pattern formed at the contact unit is displaced from the adjacent pattern of the noble metal at a half period. The area of the noble metal 2a of each contact piece 2 with the commutator becomes constant, and the graphitization produced by the friction is gathered to the bottom of the pattern. Thus, preferable commutation can be maintained for a long period to reduce the labor of maintenance. |
