Three primary types of vacuum cleaner motors exist. These motors, AC, brushed DC and brushless DC, are differentiated by the type of current required for operation and the construction of the conductors required to carry this current. Though dozens of companies throughout the world produce vacuum cleaner engines with a host of specifications, such as being waterproof and reducing noise, each of these engines can be categorised to three basic types.
AC motors are commonly used in domestic vacuum cleaners. An AC motor is one that runs on an alternating current. An alternating current is one that switches the direction of its flow 50 to 60 times per second as it travels through conductors. Unlike DC, AC is capable of adjusting to a number of voltages. Vacuum cleaner engines are often equipped to handle a range of currents, such as 100 to 240 volts; the vacuum in which it is placed will decide the voltage of the engine. As AC engines can handle varying voltages, they are ideal for engines with such a range.
Brushed DC Motors
Direct current electricity creates torque that causes a DC motor to turn. This turning produces electricity and allows the engine to run. However, torque on a DC engine will reverse direction as it moves from a perpendicular plane to a magnetic field, thus impeding engine functionality. A brushed DC motor is one that is protected against torque reversal with a device known as a brush. A brush is a carbon contact device that channels current through a commutator. A commutator reverses a current as it reverses, preventing the torque on a motor from changing directions. Vacuum motors such as the Kindly Industrial Co. Ltd. Heavy-Duty Carbon Brush DC Motor employ this technology.
Brushless DC Motors
Brushless DC motors for vacuum cleaners use solid-state semiconductor technology in place of a brush and commutator to create torque through a magnetic rotor. The magnetic rotor creates a rotating magnetic field, hence its name. This field is similar to the current produced by an AC motor in that it rotates in a single direction, without fear of reversal. Companies like Jiangsu Shangqi Group Co. Ltd. of China produce brushless DC motors for vacuum cleaners.