twin coil constant force spring for carbon brush

Twin Coil Type

1. Width of carbon brush (A)
2. Height of carbon brush (B)
: Spring width must smaller than brush height
3. Wearing length of carbon brush (C)
: Stoke must bigger than brush wearing length
4. Pressure between commutator and carbon brush (L)
: The load of the spring
5. Mounting room of brush holders (E) and (F)
: O.D. of spring (D) must smaller than both
Advantages of Twin Coil Comparing with Single Coil
1. To afford maximum brush lengtth and double the load of single coil
2. To allows a minimun motor size
3. To offer better load for its symmetry

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