Commutator made of brass

Update:19 Apr 2021

Generally, a DC motor will choose the interaction between the magnetic field of the armature and the magnetic field of the fixed stator, so that the machine can generate a force on the armature to make the machine work. At the same time, the commutator is a device connected to the armature to realize current switching.

Usually commutator manufacturers will use brass to make commutators, and at the same time they will be separated from each other by mica insulation. And the mica will be cut so that it is under the copper fracture. Later, some slots will be cut in the riser of the commutator, so that the coil can be placed in it, which is also conducive to the welding of the end of the coil.

At the same time, due to the segmented structure, they are insulated from each other. And when the brush passes from one segment to another, it touches both segments at the same time, and the induced voltage is zero. Otherwise, the brush will short-circuit both ends of the coil, causing sparks.

In an electric motor, the motor commutator will apply power to the appropriate position on the rotor. At the same time, by reversing the direction of the current in the armature coil of the motor, a stable rotation force is generated. And it can also be used in a generator to reverse the connection between the coil and the external circuit to provide unidirectional current.

Most commutators are composed of metal sheets and spring-type brushes. At the same time, the sector block is fixed on the circumference of the rotor, and the brushes are fixed on the fixed frame of the motor. Secondly, by using plastic gaskets, the conductive segments are insulated from each other.

At the same time, the brush and the commutator are required to directly maintain constant contact, and a brush holder with a spring is used. If more than one brush is required, components with multiple brushes can be installed in parallel. These parallel components will evenly distribute the current across all the brushes, so the brushes can be replaced without stopping the device.

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