1-3. Classification of Motors

Quite a few types of motor are currently being used. Therefore, they need to be appropriately classified so that you can determine which motor should be selected for what purpose, organize your ideas to explain about motors to other people, or share motor terms. The following four methods of classifying motors can be used:

• <1> Classification by the principle of conversion (electromagnetic motor, electrostatic motor, or ultrasonic motor)
• <2> Classification by power supply (DC power supply, single-phase AC power supply, or three-phase AC power supply)
• <3> Classification by rotation mode (element that determines the rotating speed or reverse rotation)
• <4> Classification by structure (combination of rotatory and static members)

The appropriate classification method depends on concepts different people have about motors. The above classification methods are based on the manufacturer's viewpoint and do not necessarily reflect usability or ease of understanding for users.

Therefore, for ease of understanding, we recently classified motors in this book by referring to the above-mentioned classifications (Fig. 1.3 DC motors). We will describe the characteristics of various motors according to this new classification.

Numbers enclosed in [ ], ( ), or <> in the figure refer to the paragraph numbers used in the explanations given later in this book.

If you are confused by the following introductions to various motors due to the many different types available, it is recommended that you return to Fig. 1.3 on the "DC motors" page to confirm how the motor is classified. Or, you may skip this part and proceed to Chapter 2, and then read this part after reading all other parts of this book.