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76-416: Once seated in the "logs", riders are taken up a conveyor belt lift hill. Part of the hill loops underneath of another part of the ride. At the top, the log takes a small drop and takes a sharp turn, intertwining with InvadR 's lift hill. When passing by treetops, the chute the ride is in expands (although rails keep the log on-track) to give the illusion the log is in a pond. A small conveyor belt then brings

152-399: A ferromagnetic core. Electric current passing through the wire causes the magnetic field to exert a force ( Lorentz force ) on it, turning the rotor. Windings are coiled wires, wrapped around a laminated, soft, iron, ferromagnetic core so as to form magnetic poles when energized with current. Electric machines come in salient- and nonsalient-pole configurations. In a salient-pole motor

228-430: A magnetic field that passes through the rotor armature, exerting force on the rotor windings. The stator core is made up of many thin metal sheets that are insulated from each other, called laminations. These laminations are made of electrical steel , which has a specified magnetic permeability, hysteresis, and saturation. Laminations reduce losses that would result from induced circulating eddy currents that would flow if

304-404: A 100- horsepower induction motor currently has the same mounting dimensions as a 7.5-horsepower motor in 1897. In 2022, electric motor sales were estimated to be 800 million units, increasing by 10% annually. Electric motors consume ≈50% of the world's electricity. Since the 1980s, the market share of DC motors has declined in favor of AC motors. An electric motor has two mechanical parts:

380-720: A 2,250-newton-per-millimetre (12,800 lb f /in), 3,400-metre-long (3,700 yd) underground belt installed at Baodian Coal Mine, part of in Yanzhou Coal Mining Company , China , was reported to provide energy savings of over 15%. Whilst Shenhua Group , has installed several aramid conveyor belts, including a 4,400-newton-per-millimetre (25,000 lb f /in) belt with a length of 11,600 m (7.2 miles). Today there are different types of conveyor belts that have been created for conveying different kinds of material available in PVC and rubber materials. Material flowing over

456-431: A 20-hp squirrel cage and a 100-hp wound rotor with a starting rheostat. These were the first three-phase asynchronous motors suitable for practical operation. Since 1889, similar developments of three-phase machinery were started Wenström. At the 1891 Frankfurt International Electrotechnical Exhibition, the first long distance three-phase system was successfully presented. It was rated 15 kV and extended over 175 km from

532-404: A 31-kilometre-long (19 mi) conveyor feeding a 20-kilometre-long (12 mi) conveyor. Cable belt conveyors are a variation on the more conventional idler belt system. Instead of running on top of idlers, cable belt conveyors are supported by two endless steel cables (steel wire rope) which are in turn supported by idler pulley wheels. This system feeds bauxite through the difficult terrain of

608-473: A Louisiana-based company, registered the first patent for all plastic, modular belting. The belt consists of one or more layers of material. It is common for belts to have three layers: a top cover, a carcass and a bottom cover. The purpose of the carcass is to provide linear strength and shape. The carcass is often a woven or metal fabric having a warp & weft . The warp refers to longitudinal cords whose characteristics of resistance and elasticity define

684-581: A cement factory at Chhatak Bangladesh . It is about 17 km (11 miles) long and conveys limestone and shale at 960 t/h (1,060 short tons per hour), from the quarry in India to the cement factory (7 km or 4.3 miles long in India and 10 km or 6.2 miles long in Bangladesh). The conveyor was engineered by AUMUND France and Larsen & Toubro. The conveyor is actuated by three synchronized drive units for

760-415: A circular section like a pipe. Like a troughed belt conveyor, a pipe conveyor also uses idler rollers. However, in this case, the idler frame completely surrounds the conveyor belt helping it to retain the pipe section while pushing it forward. In the case of travel paths requiring high angles and snake-like curvatures, a sandwich belt is used. The sandwich belt design enables materials carried to travel along

836-464: A commutator-type direct-current electric motor was built by American inventors Thomas Davenport and Emily Davenport , which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press. Due to the high cost of primary battery power , the motors were commercially unsuccessful and bankrupted the Davenports. Several inventors followed Sturgeon in

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912-463: A comparatively small air gap. The St. Louis motor, long used in classrooms to illustrate motor principles, is inefficient for the same reason, as well as appearing nothing like a modern motor. Electric motors revolutionized industry. Industrial processes were no longer limited by power transmission using line shafts, belts, compressed air or hydraulic pressure. Instead, every machine could be equipped with its own power source, providing easy control at

988-549: A conveyor is about to turn on. In the United States, the Occupational Safety and Health Administration has issued regulations for conveyor safety, as OSHA 1926.555. Some other systems used to safeguard the conveyor are belt sway switches, speed switches, belt rip switch, and emergency stops . The belt sway switch will stop the conveyor if the belt starts losing its alignment along the structure. The speed switch will stop

1064-480: A corner. These conveyor systems are commonly used in postal sorting offices and airport baggage handling systems . Belt conveyors are generally fairly similar in construction consisting of a metal frame with rollers at either end of a flat metal bed. Rubber conveyor belts are commonly used to convey items with irregular bottom surfaces, small items that would fall in between rollers (e.g. a sushi conveyor bar ), or bags of product that would sag between rollers. The belt

1140-579: A few feet to, again, avoid collisions. The log then takes its largest, most notable plunge over a large pool of water. A last, small hill drains excess water from the ride's chute and takes the logs on a sharp turn extremely close to Alpengeist's zero g roll. A pendulum is used on high-business days to separate logs into different waiting lines, and bring riders back to the boarding cabin. 37°13′59″N 76°38′52″W  /  37.233045°N 76.647896°W  / 37.233045; -76.647896 This article about an amusement ride or roller coaster

1216-422: A generator and the other as motor. The drum rotor was introduced by Friedrich von Hefner-Alteneck of Siemens & Halske to replace Pacinotti's ring armature in 1872, thus improving the machine efficiency. The laminated rotor was introduced by Siemens & Halske the following year, achieving reduced iron losses and increased induced voltages. In 1880, Jonas Wenström provided the rotor with slots for housing

1292-444: A mine to a refinery that converts the coal to diesel fuel. The third longest trough belt conveyor in the world is the 20-kilometre-long (12 mi) Curragh conveyor near Westfarmers, QLD, Australia. Conveyor Dynamics, Inc. supplied the basic engineering, control system and commissioning. Detail engineering and Construction was completed by Laing O'Rourke. The longest single-belt international conveyor runs from Meghalaya in India to

1368-437: A model electric vehicle that same year. A major turning point came in 1864, when Antonio Pacinotti first described the ring armature (although initially conceived in a DC generator, i.e. a dynamo). This featured symmetrically grouped coils closed upon themselves and connected to the bars of a commutator, the brushes of which delivered practically non-fluctuating current. The first commercially successful DC motors followed

1444-399: A path of high inclines up to 90-degree angles, enabling a vertical path as opposed to a horizontal one. This transport option is also powered by idlers. Other important components of the belt conveying system apart from the pulleys and idler rollers include the drive arrangement of reducer gear boxes, drive motors, and associated couplings. scrapers to clean the belt, chutes for controlling

1520-1037: A power grid, inverters or electrical generators. Electric motors may be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed or brushless , single-phase , two-phase , or three-phase , axial or radial flux , and may be air-cooled or liquid-cooled. Standardized motors provide power for industrial use. The largest are used for ship propulsion, pipeline compression and pumped-storage applications, with output exceeding 100 megawatts . Applications include industrial fans, blowers and pumps, machine tools, household appliances, power tools, vehicles, and disk drives. Small motors may be found in electric watches. In certain applications, such as in regenerative braking with traction motors , electric motors can be used in reverse as generators to recover energy that might otherwise be lost as heat and friction. Electric motors produce linear or rotary force ( torque ) intended to propel some external mechanism. This makes them

1596-425: A rotating bar winding rotor. Steadfast in his promotion of three-phase development, Mikhail Dolivo-Dobrovolsky invented the three-phase induction motor in 1889, of both types cage-rotor and wound rotor with a starting rheostat, and the three-limb transformer in 1890. After an agreement between AEG and Maschinenfabrik Oerlikon , Doliwo-Dobrowolski and Charles Eugene Lancelot Brown developed larger models, namely

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1672-398: A solid core were used. Mains powered AC motors typically immobilize the wires within the windings by impregnating them with varnish in a vacuum. This prevents the wires in the winding from vibrating against each other which would abrade the wire insulation and cause premature failures. Resin-packed motors, used in deep well submersible pumps, washing machines, and air conditioners, encapsulate

1748-563: A total power of about 1.8 MW supplied by ABB (two drives at the head end in Bangladesh and one drive at the tail end in India). The conveyor belt was manufactured in 300-metre (980-foot) lengths on the Indian side and 300-metre (980-foot) lengths on the Bangladesh side. The idlers, or rollers, of the system are unique{{ }} in that they are designed to accommodate both horizontal and vertical curves along

1824-437: A troughed belt conveyor is used. The trough of the belt ensures that the flowable material is contained within the edges of the belt. The trough is achieved by keeping the idler rollers in an angle to the horizontal at the sides of the idler frame. A pipe conveyor is used for material travel paths that require sharper bends and inclines up to 35 degrees. A pipe conveyor features the edges of the belt being rolled together to form

1900-579: A type of actuator . They are generally designed for continuous rotation, or for linear movement over a significant distance compared to its size. Solenoids also convert electrical power to mechanical motion, but over only a limited distance. Before modern electromagnetic motors, experimental motors that worked by electrostatic force were investigated. The first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew Gordon and American experimenter Benjamin Franklin in

1976-488: A world record, which Jacobi improved four years later in September 1838. His second motor was powerful enough to drive a boat with 14 people across a wide river. It was also in 1839/40 that other developers managed to build motors with similar and then higher performance. In 1827–1828, Jedlik built a device using similar principles to those used in his electromagnetic self-rotors that was capable of useful work. He built

2052-592: A wound rotor forming a self-starting induction motor , and the third a true synchronous motor with separately excited DC supply to rotor winding. One of the patents Tesla filed in 1887, however, also described a shorted-winding-rotor induction motor. George Westinghouse , who had already acquired rights from Ferraris (US$ 1,000), promptly bought Tesla's patents (US$ 60,000 plus US$ 2.50 per sold hp, paid until 1897), employed Tesla to develop his motors, and assigned C.F. Scott to help Tesla; however, Tesla left for other pursuits in 1889. The constant speed AC induction motor

2128-438: Is a stub . You can help Misplaced Pages by expanding it . Conveyor belt A conveyor belt is the carrying medium of a belt conveyor system (often shortened to belt conveyor). A belt conveyor system is one of many types of conveyor systems . A belt conveyor system consists of two or more pulleys (sometimes referred to as drums), with a closed loop of carrying medium—the conveyor belt—that rotates about them. One or both of

2204-584: Is a machine that converts electrical energy into mechanical energy . Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy. Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers , or by alternating current (AC) sources, such as

2280-611: Is considered a labor-saving system that allows large volumes to move rapidly through a process, allowing companies to ship or receive higher volumes with smaller storage space and with labor expense . Belt conveyors are the most commonly used powered conveyors because they are the most versatile and the least expensive. Products are conveyed directly on the belt so both regular and irregular shaped objects, large or small, light and heavy, can be transported successfully. Belt conveyors are also manufactured with curved sections that use tapered rollers and curved belting to convey products around

2356-582: Is in the developing stages and will prove to be an efficient innovation. The longest belt conveyor system in the world is in Western Sahara . It was built in 1972 by Friedrich Krupp GmbH (now thyssenkrupp) and is 98 km (61 miles) long, from the phosphate mines of Bu Craa to the coast south of El-Aaiun . The longest conveyor system in an airport is the Dubai International Airport baggage handling system at 63 km (39 miles). It

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2432-420: Is looped around each of the rollers and when one of the rollers is powered (by an electrical motor ) the belting slides across the solid metal frame bed, moving the product. In heavy use applications, the beds in which the belting is pulled over are replaced with rollers. The rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting. The exception to

2508-471: The South Side Elevated Railroad , where it became popularly known as the " L ". Sprague's motor and related inventions led to an explosion of interest and use in electric motors for industry. The development of electric motors of acceptable efficiency was delayed for several decades by failure to recognize the extreme importance of an air gap between the rotor and stator. Efficient designs have

2584-439: The armature . Two or more electrical contacts called brushes made of a soft conductive material like carbon press against the commutator. The brushes make sliding contact with successive commutator segments as the rotator turns, supplying current to the rotor. The windings on the rotor are connected to the commutator segments. The commutator reverses the current direction in the rotor windings with each half turn (180°), so

2660-410: The check-out counter to move shopping items, and may use checkout dividers in this process. Ski areas also use conveyor belts to transport skiers up the hill. Industrial and manufacturing applications for belt conveyors include package handling, trough belt conveyors, trash handling, bag handling, coding conveyors, and more. Integration of Human-Machine Interface(HMI) to operate the conveyor system

2736-416: The 1740s. The theoretical principle behind them, Coulomb's law , was discovered but not published, by Henry Cavendish in 1771. This law was discovered independently by Charles-Augustin de Coulomb in 1785, who published it so that it is now known by his name. Due to the difficulty of generating the high voltages they required, electrostatic motors were never used for practical purposes. The invention of

2812-479: The 19th century. In 1868, an English shipwright Joseph Thomas Parlour from Pimlico patented a grain elevator with a conveyor belt while Illinoisan Charles Denton of Ames Plow Co. patented a reaper with a belt "conveyer". By the 1880s conveyor belts were used in American elevators, sugarcane mills and sawmills , as well as British maltings . In 1892, Thomas Robins began a series of inventions which led to

2888-485: The B. F. Goodrich Company patented a Möbius strip conveyor belt, that it went on to produce as the "Turnover Conveyor Belt System". Incorporating a half-twist, it had the advantage over conventional belts of a longer life because it could expose all of its surface area to wear and tear. Such Möbius strip belts are no longer manufactured because untwisted modern belts can be made more durable by constructing them from several layers of different materials. In 1970, Intralox ,

2964-658: The Darling Ranges to the Worsley Alumina refinery. The second longest single trough belt conveyor is the 26.8-kilometre-long (16.7 mi) Impumelelo conveyor near Secunda, South Africa. It was designed by Conveyor Dynamics, Inc. based in Bellingham, Washington, USA and constructed by ELB Engineering based in Johannesburg South Africa. The conveyor transports 2,400 t/h (2,600 short tons per hour) coal from

3040-830: The French society REI created in New Caledonia the longest straight-belt conveyor in the world in that moment, at a length of 13.8 km (8.6 miles). Hyacynthe Marcel Bocchetti was the concept designer. . The longest conveyor belt is that of the Bou Craa phosphate mine in Western Sahara (1973, 98 km in 11 sections). The longest single-span conveyor belt is at the Boddington bauxite mine in Western Australia (31 km). In 1957,

3116-573: The Lauffen waterfall on the Neckar river. The Lauffen power station included a 240 kW 86 V 40 Hz alternator and a step-up transformer while at the exhibition a step-down transformer fed a 100-hp three-phase induction motor that powered an artificial waterfall, representing the transfer of the original power source. The three-phase induction is now used for the vast majority of commercial applications. Mikhail Dolivo-Dobrovolsky claimed that Tesla's motor

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3192-576: The belt if the switch is not registering that the belt is running at the required speed. The belt rip switch will stop the belt when there is a cut, or a flap indicating that the belt is in danger of further damage. An emergency stop may be located on the conveyor control box in case of trip chord malfunctions. Worn rubber or elastomer belts can be reused in many ways. Applications for the material include toolbox liners, anti-fatigue floor mats, dock bumpers, landscale edging, livestock fencing, and water diversion. Electric motor An electric motor

3268-463: The belt may be weighed in transit using a beltweigher . Belts with regularly spaced partitions, known as elevator belts , are used for transporting loose materials up steep inclines. Belt Conveyors are used in self-unloading bulk freighters and in live bottom trucks. Belt conveyor technology is also used in conveyor transport such as moving sidewalks or escalators , as well as on many manufacturing assembly lines . Stores often have conveyor belts at

3344-614: The belt. Steel conveyor belts are used when high strength class is required. For example, the highest strength class conveyor belt installed is made of steel cords. This conveyor belt has a strength class of 10,000 N/mm (57,000 lb f /in) and it operates at Chuquicamata mine, in Chile . Polyester, nylon and cotton are popular with low strength classes. Aramid is used in the range 630–3,500 N/mm (3,600–20,000 lb f /in). The advantages of using aramid are energy savings, enhanced lifetimes and improved productivity. As an example,

3420-520: The development of DC motors, but all encountered the same battery cost issues. As no electricity distribution system was available at the time, no practical commercial market emerged for these motors. After many other more or less successful attempts with relatively weak rotating and reciprocating apparatus Prussian/Russian Moritz von Jacobi created the first real rotating electric motor in May 1834. It developed remarkable mechanical output power. His motor set

3496-429: The development of a conveyor belt used for carrying coal, ores and other products. In 1901, Sandvik invented and started the production of steel conveyor belts. In 1905, Richard Sutcliffe invented the first conveyor belts for use in coal mines which revolutionized the mining industry. In 1913, Henry Ford introduced conveyor-belt assembly lines at Ford Motor Company 's Highland Park, Michigan factory. In 1972,

3572-478: The developments by Zénobe Gramme who, in 1871, reinvented Pacinotti's design and adopted some solutions by Werner Siemens . A benefit to DC machines came from the discovery of the reversibility of the electric machine, which was announced by Siemens in 1867 and observed by Pacinotti in 1869. Gramme accidentally demonstrated it on the occasion of the 1873 Vienna World's Fair , when he connected two such DC devices up to 2 km from each other, using one of them as

3648-456: The discharge direction, skirts for containing the discharge on the receiving belt, take up assembly for "tensioning" the belt, safety switches for personnel safety and technological structures like stringer, short post, drive frames, pulley frames make up the balance items to complete the belt conveying system. In certain applications, belt conveyors can also be used for static accumulation or cartons. Primitive conveyor belts have been in use since

3724-505: The electric energy produced in the US. In 1824, French physicist François Arago formulated the existence of rotating magnetic fields , termed Arago's rotations , which, by manually turning switches on and off, Walter Baily demonstrated in 1879 as in effect the first primitive induction motor . In the 1880s many inventors were trying to develop workable AC motors because AC's advantages in long-distance high-voltage transmission were offset by

3800-566: The electric grid, provided for electric distribution to trolleys via overhead wires and the trolley pole, and provided control systems for electric operations. This allowed Sprague to use electric motors to invent the first electric trolley system in 1887–88 in Richmond, Virginia , the electric elevator and control system in 1892, and the electric subway with independently powered centrally-controlled cars. The latter were first installed in 1892 in Chicago by

3876-470: The electrochemical battery by Alessandro Volta in 1799 made possible the production of persistent electric currents. Hans Christian Ørsted discovered in 1820 that an electric current creates a magnetic field, which can exert a force on a magnet. It only took a few weeks for André-Marie Ampère to develop the first formulation of the electromagnetic interaction and present the Ampère's force law , that described

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3952-472: The first device to contain the three main components of practical DC motors: the stator , rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings. The first commutator DC electric motor capable of turning machinery was invented by English scientist William Sturgeon in 1832. Following Sturgeon's work,

4028-579: The inability to operate motors on AC. The first alternating-current commutatorless induction motor was invented by Galileo Ferraris in 1885. Ferraris was able to improve his first design by producing more advanced setups in 1886. In 1888, the Royal Academy of Science of Turin published Ferraris's research detailing the foundations of motor operation, while concluding at that time that "the apparatus based on that principle could not be of any commercial importance as motor." Possible industrial development

4104-644: The load are exerted beyond the outermost bearing, the load is said to be overhung. The rotor is supported by bearings , which allow the rotor to turn on its axis by transferring the force of axial and radial loads from the shaft to the motor housing. A DC motor is usually supplied through a split ring commutator as described above. AC motors' commutation can be achieved using either a slip ring commutator or external commutation. It can be fixed-speed or variable-speed control type, and can be synchronous or asynchronous. Universal motors can run on either AC or DC. DC motors can be operated at variable speeds by adjusting

4180-402: The log up a few feet to avoid log collisions, and takes a steep, tall drop. Next, due to the backfiring currents of the previous drop, rapids form. After passing more rails, the log takes a small turn and near a sawmill narrowly dodged by Alpengeist . A safety recording is played in the sawmill, warning riders to "remain seated". Once in the sawmill, another small conveyor belt takes the logs up

4256-538: The magnet, showing that the current gave rise to a close circular magnetic field around the wire. Faraday published the results of his discovery in the Quarterly Journal of Science , and sent copies of his paper along with pocket-sized models of his device to colleagues around the world so they could also witness the phenomenon of electromagnetic rotations. This motor is often demonstrated in physics experiments, substituting brine for (toxic) mercury. Barlow's wheel

4332-485: The point of use, and improving power transmission efficiency. Electric motors applied in agriculture eliminated human and animal muscle power from such tasks as handling grain or pumping water. Household uses (like in washing machines, dishwashers, fans, air conditioners and refrigerators (replacing ice boxes ) of electric motors reduced heavy labor in the home and made higher standards of convenience, comfort and safety possible. Today, electric motors consume more than half of

4408-477: The production of mechanical force by the interaction of an electric current and a magnetic field. Michael Faraday gave the first demonstration of the effect with a rotary motion on 3 September 1821 in the basement of the Royal Institution . A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around

4484-821: The pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley is called the idler pulley. There are two main industrial classes of belt conveyors; Those in general material handling such as those moving boxes along inside a factory and bulk material handling such as those used to transport large volumes of resources and agricultural materials, such as grain , salt , coal , ore , sand , overburden and more. Conveyors are durable and reliable components used in automated distribution and warehousing, as well as manufacturing and production facilities. In combination with computer-controlled pallet handling equipment this allows for more efficient retail , wholesale , and manufacturing distribution . It

4560-428: The rotor and stator ferromagnetic cores have projections called poles that face each other. Wire is wound around each pole below the pole face, which become north or south poles when current flows through the wire. In a nonsalient-pole (distributed field or round-rotor) motor, the ferromagnetic core is a smooth cylinder, with the windings distributed evenly in slots around the circumference. Supplying alternating current in

4636-465: The rotor and the stator. The product between these two fields gives rise to a force and thus a torque on the motor shaft. One or both of these fields changes as the rotor turns. This is done by switching the poles on and off at the right time, or varying the strength of the pole. Motors can be designed to operate on DC current, on AC current, or some types can work on either. AC motors can be either asynchronous or synchronous. Synchronous motors require

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4712-402: The rotor, which moves, and the stator, which does not. Electrically, the motor consists of two parts, the field magnets and the armature, one of which is attached to the rotor and the other to the stator. Together they form a magnetic circuit . The magnets create a magnetic field that passes through the armature. These can be electromagnets or permanent magnets . The field magnet is usually on

4788-470: The running properties of the belt. The weft represents the whole set of transversal cables allowing to the belt specific resistance against cuts, tears and impacts and at the same time high flexibility. The most common carcass materials are steel , polyester , nylon , cotton and aramid (class of heat-resistant and strong synthetic fibers, with Twaron or Kevlar as brand names). The covers are usually various rubber or plastic compounds specified by use of

4864-461: The standard belt conveyor construction is the sandwich belt conveyor. The sandwich belt conveyor uses two conveyor belts, instead of one. These two conventional conveyor belts are positioned face to face, to firmly contain the items being carried in a "sandwich-like" hold. Belt conveyors can be used to transport products in a straight line or through changes in elevation or direction. For conveying bulk materials, over gentle slopes or gentle curvatures,

4940-454: The stator and the armature on the rotor, but these may be reversed. The rotor is the moving part that delivers the mechanical power. The rotor typically holds conductors that carry currents, on which the magnetic field of the stator exerts force to turn the shaft. The stator surrounds the rotor, and usually holds field magnets, which are either electromagnets (wire windings around a ferromagnetic iron core) or permanent magnets . These create

5016-435: The stator in plastic resin to prevent corrosion and/or reduce conducted noise. An air gap between the stator and rotor allows it to turn. The width of the gap has a significant effect on the motor's electrical characteristics. It is generally made as small as possible, as a large gap weakens performance. Conversely, gaps that are too small may create friction in addition to noise. The armature consists of wire windings on

5092-470: The terrain. Dedicated vehicles were designed for the maintenance of the conveyor, which is always at a minimum height of 5 metres (16 ft) above the ground to avoid being flooded during monsoon periods. Conveyors used in industrial settings include tripping mechanisms such as trip cords along the length of the conveyor. This allows for workers to immediately shut down the conveyor when a problem arises. Warning alarms are included to notify employees that

5168-406: The torque applied to the rotor is always in the same direction. Without this reversal, the direction of torque on each rotor winding would reverse with each half turn, stopping the rotor. Commutated motors have been mostly replaced by brushless motors , permanent magnet motors , and induction motors . The motor shaft extends outside of the motor, where it satisfies the load. Because the forces of

5244-663: The voltage applied to the terminals or by using pulse-width modulation (PWM). AC motors operated at a fixed speed are generally powered directly from the grid or through motor soft starters . AC motors operated at variable speeds are powered with various power inverter , variable-frequency drive or electronic commutator technologies. The term electronic commutator is usually associated with self-commutated brushless DC motor and switched reluctance motor applications. Electric motors operate on one of three physical principles: magnetism , electrostatics and piezoelectricity . In magnetic motors, magnetic fields are formed in both

5320-406: The winding, further increasing the efficiency. In 1886, Frank Julian Sprague invented the first practical DC motor, a non-sparking device that maintained relatively constant speed under variable loads. Other Sprague electric inventions about this time greatly improved grid electric distribution (prior work done while employed by Thomas Edison ), allowed power from electric motors to be returned to

5396-431: The windings creates poles in the core that rotate continuously. A shaded-pole motor has a winding around part of the pole that delays the phase of the magnetic field for that pole. A commutator is a rotary electrical switch that supplies current to the rotor. It periodically reverses the flow of current in the rotor windings as the shaft rotates. It consists of a cylinder composed of multiple metal contact segments on

5472-508: Was an early refinement to this Faraday demonstration, although these and similar homopolar motors remained unsuited to practical application until late in the century. In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils . After Jedlik solved the technical problems of continuous rotation with the invention of the commutator , he called his early devices "electromagnetic self-rotors". Although they were used only for teaching, in 1828 Jedlik demonstrated

5548-445: Was envisioned by Nikola Tesla , who invented independently his induction motor in 1887 and obtained a patent in May 1888. In the same year, Tesla presented his paper A New System of Alternate Current Motors and Transformers to the AIEE that described three patented two-phase four-stator-pole motor types: one with a four-pole rotor forming a non-self-starting reluctance motor , another with

5624-453: Was found not to be suitable for street cars, but Westinghouse engineers successfully adapted it to power a mining operation in Telluride, Colorado in 1891. Westinghouse achieved its first practical induction motor in 1892 and developed a line of polyphase 60 hertz induction motors in 1893, but these early Westinghouse motors were two-phase motors with wound rotors. B.G. Lamme later developed

5700-407: Was installed by Siemens and commissioned in 2008, and has a combination of traditional belt conveyors and tray conveyors. Boddington Bauxite Mine in Western Australia is officially recognized as having the world's longest single flight conveyor. Single flight means the load is not transferred, it is a single continuous system for the entire length. This conveyor is a cable belt conveyor system with

5776-438: Was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work. The General Electric Company began developing three-phase induction motors in 1891. By 1896, General Electric and Westinghouse signed a cross-licensing agreement for the bar-winding-rotor design, later called the squirrel-cage rotor . Induction motor improvements flowing from these inventions and innovations were such that

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