The basis for Molonís wide selection of DC motors and gear motors is the permanent magnet DC motor. Relatively inexpensive and compact when compared to shaded pole and PSC motors, the PM DC motor is characterized by:
Motor Housing deep drawn heavy gage sheet metal with pressed- in pre-lubed bearings. High energy ceramic magnets are twin halves pressed into the housing and trapped with spring retainers.
Armature - The armature has an odd number of armature slots and commutator bars to minimize cogging. The coils are wired into the commutator bars, which interact with the brushes I the plastic end bell. The disc varistor or capacitor, if specified, will help arrest electronic noise(EMI or EFI) generated by the brush action on the commutator. This is important is some applications utilizing electronic circuitry.
As in AC motors, the level of coil resistance is an indicator of power available. A coil of fewer turns of a heavier wire is associated with higher power motors (and also lower voltage motors.) Although the brushes are not designed for replacement like in larger DC motors, the relatively low cost and reasonable long life of this design mitigates replacements of brushes.