Puurrootormootorid

Puurrootormootorid, also known as squirrel-cage induction motors, are the most common type of alternating current (AC) electric motor. They are characterized by a rotor constructed from conductive bars, typically aluminum or copper, embedded in a laminated iron core and short-circuited at both ends by conducting rings. This design resembles a squirrel cage, hence the name.

The operation of a puurrootormootor relies on the principle of electromagnetic induction. When a three-phase AC voltage is applied to the stator windings, it creates a rotating magnetic field. This rotating field induces a voltage in the rotor bars. Due to the closed circuit of the rotor, this induced voltage causes current to flow through the rotor bars. The interaction between the stator's rotating magnetic field and the magnetic field produced by the rotor currents generates a torque, causing the rotor to spin.

The speed of a puurrootormootor is always slightly less than the speed of the rotating magnetic field, a phenomenon known as slip. This slip is essential for inducing current in the rotor. The speed can be controlled by varying the frequency of the AC power supply, typically using a variable-frequency drive (VFD).

Puurrootormootorid are favored for their simplicity, robustness, low cost, and low maintenance requirements. They are widely used in industrial applications such as pumps, fans, compressors, conveyors, and machine tools, as well as in household appliances like washing machines and refrigerators. Their inherent reliability makes them a workhorse of modern electrical machinery.