Types of Electric Motors and Brake Motors

When it comes to the efficiency of a motor, there are several options available. For example, there are AC induction motors and DC induction motors. AC induction motors can coast to a stop when the induced field is removed. On the other hand, an electric braking system may provide a faster stop. In both cases, the braking system involves the application of DC voltage to the stationary windings of the motor. The DC voltage creates a magnetic field in the stator, but this magnetic field will not change polarity.

Synchronous motors, on the other hand, use a squirrel cage to bring the rotor close to synchronous speed. The squirrel cage structure, as well as a small induction motor, are used in various designs. In these systems, the rotor starts in the forward direction. The lack of anti-reversal mechanisms makes the motor unpredictable in direction. As a result, AC power is used to reverse the direction of the motor.

Induction motors are a popular choice for continuous duty applications. Since the magnetic field is not synchronized, they operate with a lag between the rotations. This gives them a 30-revolution overrun even after the power is removed. The design is shown in the below image. This type of motor is the most common and is suited for continuous duty. It is the most common type of induction motor. Its durability makes it a good choice for any application.

An AC induction motor starts at zero torque (Ts) and gradually accelerates past an unstable region to a steady speed, or “P” in the rotor's speed. As the rotor and stator move along the curve, the difference in speed between them will change and the motor will eventually stall. The induced current is then applied to the output shaft, producing torque. These two types of motors are the most common in industrial applications.

Another type of asynchronous motor is the brake motor. This type is fully enclosed and fan-cooled. Its two principal poles are separated halfway, resulting in four half-poles. These half-poles were connected to two sets of terminals, one common and the other. Connecting one pair to one terminal caused the motor to run one direction, while connecting another terminal caused it to run the other way. These motors are used in industrial applications.

Brushless motors are also available. Brushless motor systems have more advantages over brushed motors, but they require drivers to electrically commute the motor windings, which increases the overall cost per axis. Continuous duty conveyors, for example, may need advanced speed control. A radially segmented permanent magnet is used in the rotor. Oriental Motor does not manufacture brushed motors, but it does offer brushless motors.

AC induction motors depend on magnetism. A typical AC motor has a coil of wire and two fixed magnets around the shaft. When a current flows through the coil, it becomes an electromagnet, creating a magnetic field that causes the rotor to rotate. The current flow is the force that drives the rotor. The speed of the rotor shaft depends on the operating frequency and the number of pole pairs in the motor windings.