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Dual-rotor Permanent Magnet Induction Motor
A dual-rotor permanent magnet induction motor (DRPMIM) is a motor having two rotors within the same motor housing. This rotor arrangement can increase power volume density, efficiency, and reduce cogging torque. Some dual-rotor permanent magnet induction motors are a type of induction motors, while others are not actually induction motors. Stator on the outside In one arrangement, the motor has an ordinary induction motor stator. A squirrel-cage rotor A squirrel-cage rotor is the rotating part of the common squirrel-cage induction motor. It consists of a cylinder of steel laminations, with aluminum or copper conductors embedded in its surface. In operation, the non-rotating stator winding i ... connected to the output shaft rotates within the stator at slightly less than the rotating field from the stator. Within the squirrel-cage rotor is a freely rotating permanent magnet rotor, which is locked in with rotating field from the stator. The effect of the inner rotor i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotor (electric)
The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Its rotation is due to the interaction between the windings and magnetic fields which produces a torque around the rotor's axis.Staff. "Understanding Alternators. What Is an Alternator and How Does It Work." N.p., n.d. Web. 24 November 2014 . Early development An early example of electromagnetic rotation was the first rotary machine built by Ányos Jedlik with electromagnets and a commutator, in 1826-27. Other pioneers in the field of electricity include Hippolyte Pixii who built an alternating current generator in 1832, and William Ritchie's construction of an electromagnetic generator with four rotor coils, a commutator and brushes, also in 1832. Development quickly included more useful applications such as Moritz Hermann Jacobi's motor that could lift 10 to 12 pounds with a speed of one foot per second, about 15 watts of mechanical power in 1834. In 1835, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Volume Density
Power density is the amount of power (time rate of energy transfer) per unit volume. In energy transformers including batteries, fuel cells, motors, power supply units etc., power density refers to a volume, where it is often called volume power density, expressed as W/m3. In reciprocating internal combustion engines, power density (power per swept volume or brake horsepower per cubic centimeter) is an important metric, based on the ''internal'' capacity of the engine, not its external size. Examples See also *Surface power density, energy per unit of area *Energy density, energy per unit volume * Specific energy, energy per unit mass *Power-to-weight ratio/specific power, power per unit mass **Specific absorption rate Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed per unit mass by a human body when exposed to a radio frequency (RF) electromagnetic field. It can also refer to absorption of other forms of energy by tissue, inc ... (S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cogging Torque
Cogging torque of electrical motors is the torque due to the interaction between the permanent magnets of the rotor and the stator slots of a permanent magnet machine. It is also known as ''detent'' or ''no-current torque''. This torque is position dependent and its periodicity per revolution depends on the number of magnetic poles and the number of teeth on the stator. Cogging torque is an undesirable component for the operation of such a motor. It is especially prominent at lower speeds, with the symptom of jerkiness. Cogging torque results in torque as well as speed ripple; however, at high speed the motor moment of inertia filters out the effect of cogging torque. Reducing the cogging torque A summary of techniques used for reducing cogging torque: * Skewing stator stack or magnets * Using fractional slots per pole * Optimizing the magnet pole arc or width Almost all the techniques used against cogging torque also reduce the motor counter-electromotive force and so reduce the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Motor
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type. Three-phase squirrel-cage induction motors are widely used as industrial drives because they are self-starting, reliable and economical. Single-phase induction motors are used extensively for smaller loads, such as household appliances like fans. Although traditionally used in fixed-speed service, induction motors are increasingly being used with variable-frequency drives (VFD) in variable-speed service. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications. Squirrel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squirrel-cage Rotor
A squirrel-cage rotor is the rotating part of the common squirrel-cage induction motor. It consists of a cylinder of steel laminations, with aluminum or copper conductors embedded in its surface. In operation, the non-rotating stator winding is connected to an alternating current power source; the alternating current in the stator produces a rotating magnetic field. The rotor winding has current induced in it by the stator field, like a transformer except that the current in the rotor is varying at the stator field rotation rate minus the physical rotation rate. The interaction of the magnetic fields of currents in the stator and rotor produce a torque on the rotor. By adjusting the shape of the bars in the rotor, the speed-torque characteristics of the motor can be changed, to minimize starting current or to maximize low-speed torque, for example. Squirrel-cage induction motors are very prevalent in industry, in sizes from below up to tens of megawatts (tens-of-thousand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Electrotechnical Commission
The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". IEC standards cover a vast range of technologies from power generation, transmission and distribution to home appliances and office equipment, semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine energy as well as many others. The IEC also manages four global conformity assessment systems that certify whether equipment, system or components conform to its international standards. All electrotechnologies are covered by IEC Standards, including energy production and distribution, electronics, magnetics and electromagnetics, electroacoustics, multimedia, telecommunication and medical technology, as well as associated general disciplines such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HarperCollins
HarperCollins Publishers LLC is one of the Big Five English-language publishing companies, alongside Penguin Random House, Simon & Schuster, Hachette, and Macmillan. The company is headquartered in New York City and is a subsidiary of News Corp. The name is a combination of several publishing firm names: Harper & Row, an American publishing company acquired in 1987—whose own name was the result of an earlier merger of Harper & Brothers (founded in 1817) and Row, Peterson & Company—together with Scottish publishing company William Collins, Sons (founded in 1819), acquired in 1989. The worldwide CEO of HarperCollins is Brian Murray. HarperCollins has publishing groups in the United States, Canada, the United Kingdom, Australia, New Zealand, Brazil, India, and China. The company publishes many different imprints, both former independent publishing houses and new imprints. History Collins Harper Mergers and acquisitions Collins was bought by Rupert Murdoch's News Corpora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotor For Dual Rotor Motor
Rotor may refer to: Science and technology Engineering *Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator *Helicopter rotor, the rotary wing(s) of a rotorcraft such as a helicopter *ROTOR, a former radar project in the UK following the Second World War *Rotor (turbine), the rotor of a turbine powered by fluid pressure *Rotor (crank), a variable-angle bicycle crank *Rotor (brake), the disc of a disc brake, in U.S. terminology * Rotor (brake mechanism), a device that allows the handlebars and fork to revolve indefinitely without tangling the rear brake cable - see Detangler * Rotor (distributor), a component of the ignition system of an internal combustion engine *Pistonless rotary engine *Rotor (antenna) Computing *Rotor machine, the rotating wheels used in certain cipher machines, such as the German Enigma machine ** Rotor (Enigma machine), a rotating part of the German Enigma machine *Rotor (so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wisconsin Alumni Research Foundation
The Wisconsin Alumni Research Foundation is the independent nonprofit technology transfer organization serving the University of Wisconsin–Madison and Morgridge Institute for Research. It provides significant research support, granting tens of millions of dollars to the university each year and contributing to the university's "margin of excellence". History WARF was founded in 1925 to manage a discovery by Harry Steenbock, who invented the process for using ultraviolet radiation to add vitamin D to milk and other foods. Rather than leaving the invention unpatented—then the standard practice for university inventions—Steenbock used $300 of his own money to file for a patent. He received commercial interest from Quaker Oats but declined the company's initial offer. Instead, Steenbock sought a way to protect discoveries made by UW-Madison faculty, ensure use of the ideas for public benefit and bring any financial gains back to the university. His concept gained s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
