| 摘要 |
PURPOSE:To readily enable to confirm and repair the fusion-broken pig tails of positive brushes connected to a switch of a DC machine by determining the sectional area of the pig tails in size to be fusion-broken by the overcurrent of the magnitude which causes irreversible reduction in the magnetization, thereby effectively preventing the irreversible reduction of a permanent magnet in the magnetization of the permanent magnet. CONSTITUTION:The pig tails 51A, 51B of positive brushes 5A, 5B are formed in a structure branched in the course in such a manner that the sectional area of the pig tail 51A is formed in thickness to be fusion-broken by the maximum overcurrent which does not cause an irreversible reduction in the magnetization of a permanent magnet in designing to prevent the irreversible reduction in the magnetization of the magnet due to the reduction in the magnetic field by an armature reaction from the result that an overcurrent flows through an armature coil, while the pig tails 51B, 61 are formed in a sufficient thickness. Further, the connecting position of the pig tails 51A, 51B is disposed at the position in the vicinity of the terminal 31 of a starter switch 37 at a DC machine side, and disposed so as not to extremely increase the electric resistance of an electric circuit. |
