The generator brush sparks the cause of the problem is?

1,brush current density is too large.In the actual operation,if one or two brush jamming due to

mechanical trouble,lack of spring pressure don't output,in order to maintain the normal load,by other brush of current will increase,if there are in the increasing flow of the brush the slant of the

brush,because with the slip ring contact area is reduced,surface flow density increases.According to Q = I * IRT,calorific value and is proportional to the square of the current,the accumulation of heat to send out,the temperature rise sharply,the brush and slip ring interface can produce sparks.Also spark,after the creation of the brush work environment more bad,so a vicious circle,make brush sparks more serious,a few have this severe cases will occur when the three phase induction motor ring of fire.2,uneven brush pressure,or do not conform to the requirements.

Brush factory manufacturers are related: brush spark does not occur to the lowest pressure,pressure adjustment go through scientific argumentation and practice summary,minimum pressure generally is 200 ~ 300 ㎡ ɡ / c,is 0.02 ~ 0.03 MPa,the pressure between each brush also wants even,its difference is not more than 10.The generator in the long run if a brush friction are too short,or brush in the brush frame www.dongfeng-motor.com delay CARDS,pressure will be uneven.Moreover by machinery,heat soft spring itself and other factors affect the pressure can not meet the brush doesn't happen spark theory of minimum requirements.And we are compaction,tyra carbon brush,sometimes feel,no accumulation of experience,operating error is very great.3,the surface of the brush is not clean.

This is the most let people ignore,normal operation of the generator brush seal inside the airtight cabinet,there are set on the shaft gear shape among the poles brush axial flow fan,depend on rotor rotating grinding of graphite carbon powder,heat away in time,brush to clean ac geared motor the cooling effect.If the cupboard door closed lax,or forget to close the door,when checking out the dust with the hot air into the brush,brush attached to the column,on the one hand brush heat dissipation.On the other hand brush spark occurs due to brush the column surface impurity,brush column insulation strength between ring fire easily.Besides slip ring on have spiral groove,this is in order to increase the brush the cooling area,improve with brush contact,makes the brush more fully cooling,at the same time are more likely to make carbon powder.If cupboard door closed lax,lack of draught fan outside dust very easily also adhere to the spiral ditch,consequences was palpable.Excitation single phase capacitor start induction motor electrical and mechanical brush consider its bare outside,the lower voltage level in this also suggests the maintenance regularly clean.A few days ago excitation brush sparks was forced to stop incidents happened in our factory,the reason of many sided,often small disaster.We should cause enough attention.