A squirrel cage rotor is the rotating part commonly used in an AC induction motor. An electric motor with a squirrel cage rotor is sometimes called squirrel cage motor. In overall shape it is a cylinder mounted on a shaft. Internally it contains longitudinal conductive bars of aluminium or copper set into grooves and connected together at both ends by shorting rings forming a cage-like shape. The name is derived from the similarity between this rings-and-bars winding and the wheel on which pet rodents (including squirrels) run. Electric motors of various sizes. ... Electric motors of various sizes. ... Families See Classification Section The order Rodentia is the most numerous of all the branches on the mammal family tree. ... Genera Many, see the article Sciuridae. ...

The core of the rotor is built of a stack of iron laminations. The drawing shows only three laminations of the stack. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ...

Drawing of rotor

The field windings in the stator of an induction motor set up a rotating magnetic field around the rotor. The relative motion between this field and the rotation of the rotor induces electrical current flow in the conductive bars. In turn these currents flowing lengthwise in the conductors react with the magnetic field of the motor to produce force acting at a tangent to the rotor, resulting in torque to turn the shaft. In effect the rotor is carried around with the magnetic field but at a slightly slower rate of rotation. The difference in speed is called “slip” and increases with load. Synchronous motors must use other types of rotors although they may employ a squirrel cage winding to allow them to reach near-synchronous speed upon starting. drawing of squirrel cage rotor Drawn by user Meggar Insert non-formatted text here File links The following pages link to this file: Squirrel cage rotor Categories: GFDL images ... drawing of squirrel cage rotor Drawn by user Meggar Insert non-formatted text here File links The following pages link to this file: Squirrel cage rotor Categories: GFDL images ... The stator is the fixed part of a rotating machine. ... Current flowing through a wire produces a magnetic field (M) around the wire. ... In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ... In physics, a force is an external cause responsible for any change of a physical system. ... In mathematics, the word tangent has two distinct, but etymologically related meanings: one in geometry, and one in trigonometry. ... In physics, torque can be thought of informally as rotational force. Torque is measured in units of newton metres, and its symbol is Ï„. The concept of Torque, also called moment or couple, originated with the work of Archimedes on levers. ... Synchronization is coordination with respect to time. ...

The conductors are often skewed slightly along the length of the rotor to reduce noise and smooth out torque fluctuations that might result at some speeds due to interactions with the pole pieces of the stator.

The iron core serves to carry the magnetic field across the motor. In structure and material it is designed to minimize losses. The thin laminations, separated by varnish insulation, reduce stray circulating currents that would result in eddy current loss. The material is a low carbon but high silicon iron with several times the resistance of pure iron, further reducing eddy-current loss. The low carbon content makes it a magnetically soft material with low hysteresis loss. As the circular plate moves down through a small region of constant magnetic field directed into the page, eddy currents are induced in the plate. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... Hysteresis is a property of systems (usually physical systems) that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state: that is, systems whose states depend on their immediate history. ...

The same basic plan is used for both single-phase and three-phase motors over a wide range of sizes. Rotors for three-phase will have variations in the depth and shape of bars to suit the design classification.