Showing posts with label brush. Show all posts
Showing posts with label brush. Show all posts

Thursday, February 17, 2011

Commutator and Slip Ring

In principle commutator insulation should be recessed below the surface of the segments, unless hard carbon brushes are used. Segment edges should be bevelled to ensure on the one hand proper communication and on the other to avoid high brush wear or brush breakage.
 Commutator

 Slip Ring


Wednesday, February 9, 2011

DC Electric Motor

In any electric motor, operation is based on simple electromagnetism. A current-carrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. As you are well aware of from playing with magnets as a kid, opposite (North and South) polarities attract, while like polarities (North and North, South and South) repel. The internal configuration of a DC motor is designed to harness the magnetic interaction between a current-carrying conductor and an external magnetic field to generate rotational motion.
Let's start by looking at a simple 2-pole DC electric motor (here red represents a magnet or winding with a "North" polarization, while green represents a magnet or winding with a "South" polarization).

Every DC motor has six basic parts -- axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and