Current, the drive means of dynamoelectric bicycle is hub type mostly, have direct drive, also have gear decelerate drive. Among them, direct drive means uses motive of low speed dc (minutely turn hundreds of turn) , and means of gear decelerate drive uses the dc motor with higher rotate speed (general 2000r/min above) , will satisfy the travelling speed that dynamoelectric bicycle needs through gear decelerate. Former advantage is not to need gear decelerate, simplified consequently structure, rose but * sex, reduced noise; Latter good point is bulk small, weight is light.
No matter be which kinds of drive,electric machinery divides the hub of means to brush dc to have motive and without brush dc motive two kinds. Use have brush dc motive, the advantage is control simple, controller structure is consequently simple, but * sex good, fault rate is low. But because there are commutator and brush inside electric machinery (weigh carbon brush again) existence, produce inverting problem, it is to have one of parent that brush dc motive to give trouble easily. Accordingly, how improving inverting is to assure to have brush dc motive (electric machinery of dc of the following abbreviation) quality and the serious problem that reduce repair rate. The inverting problem of dc machine talks below.
1, the evaluation of inverting qualification
The inverting of dc machine is to point to rotating armature winding component, the commutation process of direction of the electric current in the component when from spur track enters another spur track through brush (abbreviation inverting) . In the process that alternates in voltaic direction, want to produce scintilla between brush and commutator commonly, it is inverting difficulty and the main reason that produce breakdown. So, national level divides his into a few grade according to size of the scintilla when electric machinery inverting (1, 5/4, 3/2, 2, 3) . To the dc electric machinery of successive job, its inverting scintilla should not exceed 3/2 level. Dynamoelectric bicycle belongs to the electric machinery of successive job with dc machine, should satisfy the requirement that is not more than 3/2 class scintilla. Standard regulation: When 3/2 class scintilla, major or brush margin is overall have faint scintilla, because there is black mark to appear on this commutator, but won't continue to develop, brush its face with benzine namely can eliminate, there is slight bright mark on brush at the same time, these won't affect electric machinery to move normally continuously.
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