brush and spring kits

[The Big Labowski]

what exactly are these meant to replace? what mechanisms have brushes and springs? Is the spring the circular part that spins against the brush to make it wind up? i am just unclear on where and what springs are.

[Jim_Ferer]

This is from a supplier's website and seems like a good explanation:

http://www.reedlink.com/ProductInfo~Pro ... ushes.html

Brushes make contact with current carrying parts and transfer power. I didn't see a mention of springs in this article but from other sites it seems the springs hold the brush in contact.

[AllSafe]

On series- or shunt-wound universal motors, brushes are used to transfer power to the commutator. The springs hold the brushes against the commutator. On most rotating sirens, there are two sets of brushes; one is in the rotator and it transfers power to the main motor through slip rings.