First of all, check the brush and commutator between there is no dirt, found that there is dirt should be cleaned up in time to avoid the accumulation of too much dirt caused by poor contact. Then check the middle of the commutator nut there is no protruding part, if found that the surface is not flat should use sandpaper to polish the commutator surface flat, otherwise it will cause the commutator and brush sliding obstruction, after friction spark. Next, we should check the brush holder to see if there is any improper adjustment, improper adjustment will easily cause the brush pressure is too large, causing friction, should adjust the brush holder so that the brush pressure is appropriate. Finally, we should check the brush box to see if there is loose, brush box assembly specification is not, we should pay attention to adjust the position of the brush or strengthen the brush box. General overhaul of the brush sparking causes mostly for the brush and commutator middle dirt, poor contact and discharge, so here is the focus to check carefully.

Reduce the bore diameter of the motor within a reasonable range, reduce the air flow of the motor and other details to substantially increase the vacuum air pressure of the motor.