ELECTRIC DC MOTORS

  Most rotary motion applications today depend on motors. Electric Motors are dominant, though air and hydraulic motors are preferred in some applications, and engines or turbines drive others. Several types of electric motors turn shafts: dc, ac, servo, and step motors. Also, a motor may be just a motor or it may be a gearmotor; that is, it may have an integral geared speed reducer. Air motors are usually rotary vane or piston type; hydraulic motors are rotary vane, piston, orgear type. Each has operating characteristics inherent to its basic design. Thus, motor selection is often a process of matching application requirements to performance parameters of the various types, then selecting the most compatible.

  

Performance, however, is not the only criterion in motor selection. To optimize selection, choose an enclosure that protects the inner workings of the motor from the environment. Moreover, you must consider the best mounting arrangement, such as base or flange mount. Also, consider ways to protect the motor from overloads and line fluctuations.

The following discussion deals with electric motors for rotary motion. For electric motors for linear motion, see the Linear Motion Devices Product Department in this handbook.