| 摘要 |
PURPOSE:To prevent the ignition of an armature winding by fixing a brush holder storing a brush to a support molded to a discoid shape by a plastic material, etc., having the low thermal deformation temperature within a range in which there is no trouble on normal usage. CONSTITUTION:A brush 2 is stored into a brush holder 3 composed of a discoid member the thermal deformation temperature of which extends over the ignition point or less of a winding. When the temperature of the inside of a motor is elevated to a certain fixed temperature, the brush holder 3 begins to be deformed. The brush 2 is tilted by the eyebrow-shaped deformation of the brush holder 3, contact resistance between the brush 2 and a commutator 11 is increased suddenly, and conduction of the winding is brought to the state of interruption or the state close to said state.
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