Commutation device for direct current machine e.g. starter device for internal combustion engine, has commutator and positive and negative brushes, which are made of materials having different copper content

摘要

The commutation device comprises commutator (55) and positive and negative brushes (58). The positive brush is made of material having higher copper content than that of negative brush such as commutator (52). The contact pressure of commutator (52) is between 10-25 N/cm 2>. The contact pressure of positive bursh is 5 N/cm 2>.