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see generatorgenerator,
in electricity, machine used to change mechanical energy into electrical energy. It operates on the principle of electromagnetic induction, discovered (1831) by Michael Faraday.
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; motor, electricmotor, electric,
machine that converts electrical energy into mechanical energy. When an electric current is passed through a wire loop that is in a magnetic field, the loop will rotate and the rotating motion is transmitted to a shaft, providing useful mechanical work.
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The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in engineering. (1) The rotating part of motors and machines, in which are located the members that receive energy from the working medium (for instance, the rotor in a Wankel engine) or that transmit energy to a working medium (for instance, the rotor in a rotary pump). In motors, the rotor is connected to a driving shaft; in machines, it is connected to a driven shaft. Rotors are made in the shape of drums, disks, or wheels.

(2) The rotating part of, as a rule, an alternating-current machine. It is usually a cylindrical body with grooves that contain the winding.



the rotating part of an electric machine. As a rule, the concept of a rotor refers to alternating-current machines; in direct-current machines, the rotor is called an armature.

The rotor of an induction machine is usually fabricated from electrical sheet steel and has the shape of a cylinder with grooves that contain the winding. Depending on the type of winding used, induction machines are classified as either phase-wound or squirrel-cage machines. A phase-wound rotor has a three-phase winding with the same number of sections as are in the stator. The sections are usually Y-connected, and their terminals are connected to a starting rheostat through collector rings and brushes. The winding of a squirrel-cage rotor consists of metal bars that are short-circuited at each end.

Rotors in synchronous machines are classified as salient-pole and nonsalient-pole rotors. A salient-pole rotor consists of a yoke and of poles attached to the yoke and equipped with field windings. A nonsalient pole rotor is usually fabricated as a unit from a single steel forging. Grooves for field winding are milled into the forging.


Kostenko, M. P., and L. M. Piotrovskii. Elektricheskie mashiny, 3rd ed., parts 1–2. Leningrad, 1972–73.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(aerospace engineering)
An assembly of blades designed as airfoils that are attached to a helicopter or similar aircraft and rapidly rotated to provide both lift and thrust.
Disk with a set of input contacts and a set of output contacts, connected by any prearranged scheme designed to rotate within an electrical cipher machine.
Disk whose rotation produces a variation of some cryptographic element in a cipher machine usually by means of lugs (or pins) in or on its periphery.
The rotating member of an electrical machine or device, such as the rotating armature of a motor or generator, or the rotating plates of a variable capacitor.
(mechanical engineering)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


i. A system of rotating airfoils whose primary function is to produce lift (e.g., propellers and helicopter rotors).
ii. The portion of a turbine or compressor that spins.
iii. A rotating disc or drum to which a series of blades are attached (e.g., compressor, turbine, turbopump, alternator).
iv. A local air mass rotating about a substantially horizontal axis.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved


1. the rotating member of a machine or device, esp the armature of a motor or generator or the rotating assembly of a turbine
2. a device having blades radiating from a central hub that is rotated to produce thrust to lift and propel a helicopter
3. the revolving arm of the distributor of an internal-combustion engine
4. a violent rolling wave of air occurring in the lee of a mountain or hill, in which the air rotates about a horizontal axis
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
These will all have to rely on rotors for the seemingly magical play of lights that will sync with Christmas carols and modern songs in the contest's three rounds.
A lantern can have five to 10 rotors, based on the number and variety of patterns.
4, the step harmonics play a disturbing role in machine's operation (produce significant asynchronous torques) especially in case of straight bars rotor. Harmonic components obtained from subsequent spectral analyses are all referred to the fundamental wave of the straight rotor machine (seen in Fig.
While the straight rotor cage provides the operation with amount of disruptive effects (cogging torque, torque ripple, vibrations and noise) caused by unsuppressed air gap harmonics, the skewed rotor cage may reduce them significantly.
After systematically analysis of the various structures and parameters of tilting pad bearing, elliptical bearing, and cylindrical journal bearing, it can be found that the response characteristics of the rotor system supported by cylindrical bearing are the best.
Experimental Study on the Effects of Different Bearings on Rotor Vibration
where matrices Mr, Cr, Gr, and Kr are mass, damping, gyroscopic, and stiffness matrices of the rotor system,
This speed oscillation can reduce the magnitude of the LSB [18], but an upper sideband (USB) current component also appears in the stator windings due to rotor speed oscillation [26].
The curved wall was used to divert downstream wind flow in order to observe diversion effects on the rotor performance.
Recent efforts have focused on validation of rotor airloads [21] and blade structural loads [22] by simulating the UH-60A as an isolated rotor in free air (wind tunnel wall effects are accounted for with a shaft angle correction).
The rotor-to-stator system with a Jeffcott rotor and an active auxiliary bearing is shown in Figure 1(a).