NdFeB magnets in DC linear stepping motors

Advantages of DC linear motors over rotary ones in most applications requiring linear drives, are numerous. Linear motors are free of chains, gears or belts and hence compact, and have no backlashes. Unlike linear AC motors these have limited travel but are more easily controllable. The magnetic field source for these motors can be chosen to be electromagnets or permanent magnets. The replacement of the electromagnets by permanent magnets is only possible because of the superior magnetic properties of the permanent magnets presently available. The author describes the construction, analysis and performance of several NdFeB field DC linear motors