| 摘要 |
PURPOSE:To prevent the jumping of a brush without increasing the compressive force of a spring by combining a plurality of elastic materials having different elastic moduli and pressure-welding the brush to a slip ring. CONSTITUTION:An energizing means 20 on the positive side consists of a rubber member 32 fitted on a bottom in a brush receiving hole 22, a compression coil spring 33 arranged between the rubber member 32 and a brush 16 and a tabular overlap 34 disposed between the rubber member 32 and the compression coil spring 33. The natural frequency of the rubber member 32 and the natural frequency of, the compression coil spring 33 are made to differ. The same applies to an energizing means 21 on the negative side. Accordingly, even when the frequency of external force coincides with the natural frequency of one elastic material and the elastic material generates resonance, the other elastic material absorbs the resonance, thus suppressing the jumping of a brush due to the resonance of the elastic material.
|
