When starting eddy current clutch operates at 100% slip allow the driver motor to accelerate. Eddy current clutch working, application, advantages and. The eddy current rail brake can achieve a stable brake force without depending on adhesion between the rail and the wheel. Amtrak mechanical department bureau of rolling stock. The rotor and the stator are made of high quality magnetic materials and subjected to heat treatment. With the engine removed examine the tundish for fractures or damage, particularly in the area of the waste drain pipe. Thus the operation of this cooling system is entirely automatic and is fully interlocked with the other. They were standardized mechanically and in overall design. They are an adjustable speed drive and provide soft starting capability. The above information except the value of a guinea comes. Traction motors in diesel locomotives ee publishers.
What are the electrical rotating machines available in wdg4 locomotive. Sep 22, 2006 tractive effort determines how much a locomotive can haul. The reference text on which this subcourse is based is a broad presentation of locomotive structure and a basic outline of maintenance. An electrodiesel locomotive also referred to as a dualmode or bimode locomotive is powered either from an electricity supply like an electric locomotive or by using the onboard diesel engine like a dieselelectric locomotive. There is a gap between rotor and magnetic pole so no wear occurs during operation. Together with the tach generator stator, it puts out a signal proportional to the output rpm so the controller can regulate the speed of the clutch. The b unit still works fine, but the a unit will no longer move. As the motor speeds up, backemf reduces the current and the torque, and series resistance is switched out stepbystep to maintain the required torque until full speed is attained.
Eddy current brake design for operation with extreme back. It has full sound but wont move forward or backward. Diesel free delivery possible on eligible purchases. Eddy current, as well as a variety of related products and services. Obviously, in the states, it is hard to find a book on how to prepare, fire, and drive a british steam locomotive. The supplier of this item is approved as a verified supplier. Alco used a right angle drive and eddy current clutch to run radiator fans on the 244 and 251 road units. Unlike the friction brakes, which apply pressure on two separate objects, eddy current brakes slow an object by creating eddy currents. Nov 27, 2012 trains magazine offers railroad news, railroad industry insight, commentary on todays freight railroads, passenger service amtrak, locomotive technology, railroad preservation and history, railfan opportunities tourist railroads, fan trips, and great railroad photography. Union pacifics e2 cab unit was distinguished from the slantnosed ea and e1 units by its bulbous nose, round porthole style windows, and stainless steel ornamentation on the pilot and nose.
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on board energy storage such as a battery or a supercapacitor electric locomotives with on board fueled prime movers, such as diesel engines or gas turbines, are classed as dieselelectric or gas turbineelectric and not as electric locomotives, because the electric generatormotor combination. Eddy current drive for model railroad engines model. An eddy current brake, like a conventional friction brake, is responsible for slowing an object, such as a train or a roller coaster etc. Thus the transferable moment increases with the relative rpm.
The eddycurrent brake releases the braking force by inducing in the rail linear eddycurrent brake see fig. Distributor of eddy current or induction motors or drives. The eddycurrent drive or clutch is a slip device consisting of two rotating elements that. Frictiondrive locomotives are rare, probably because having one frictional interface of doubtful dependability, between wheel and rail, is quite enough uncertainty for most people. The analysis of eddycurrent brakes for a highspeed railway is described that shows the operational characteristics of the brake as function of the train speed up. Most of the parts of a dieselelectric locomotive are electrical. In mountain areas where continuous braking force is needed, for a long time, the eddy current braking is very much useful for working without overheating. The eddycurrent drive also called a magneticallycoupled adjustable speed drive, which consists of an eddycurrent clutch and associated controls, is favored for heavyduty applications with high starting torque and severe shock loads. Design of an eddy current torque bypass clutch for seamless. They were built by english electric and the new zealand railways department nzr between 1938 and 1940, and hauled mainly passenger trains on the wellington regions 1500 v dc electrification, and banked freight trains on the steep section between paekakariki and pukerua. A radiator fan is used on diesel electric locomotives to bring down the temperature of the diesel engine cooling water. The analysis of eddy current brakes for a highspeed railway is described that shows the operational characteristics of the brake as function of the train speed up to 300 kmhr and of the dc. Variable frequency drives and dc drives operate by electronically altering the input power to control the speed of the motor. Bachmann industries emd f7b diesel locomotive dcc equipped great northern train car, greenorange, n scale.
Im presently waiting for larger stronger magnets to build a better eddy current slip clutch. Find types of eddy current clutch motor related suppliers, manufacturers, products and specifications on globalspec a trusted source of types. In ecc eddy current clutch, clutching of inner and outer drum is through. Its weight does tend to become comparatively heavy. A wide variety of manufacturers, distributors and service companies are featured in our extensive vertical directory to allow ease sourcing and research for drives. Alco diesel electric locomotive the two diesel electric. The eddy current drive or clutch is a slip device consisting of two rotating elements that. A parametric analysis of magnetic braking the eddy current. The current genset configurations use two 2 or three 3 smaller diesel engines and generators to replace a single primemover. A stationary study was done to evaluate the eddy current generated in the disc. When a traction motor is switched to provide dynamic braking, the resistance of the armature when it acts as a generator is enough to slow the locomotive down. While the locomotive manufacturers focus on market niches, car manufacturers typically supply a range of cars.
There were a couple of control schemes, and ill describe how the simplest one worked. Buy bachmann industries emd f7b diesel locomotive dcc equipped erie lackawanna train car, graymaroon, n scale. It needed less maintenance, used less fuel and could be operated with a smaller crew. Linear eddy current brake design features of eddy current brakes. Design of an eddy current torque bypass clutch for.
Amtrak mechanical department bureau of rolling stock engineering. The reason of the trends observed in the above to graph is because, as stated by lorentz law, mentioned above, as the relative velocity increases the magnitude of eddy current induced in disc increases which causes, and thus the induced eddy currents would try to oppose the cause producing it and hence higher value of braking torque is obtained. Is it costeffective to replace old eddycurrent drives. How does dynamic braking work on a locomotive traction. Dynaspede offers a comprehensive range of eddy current clutches, brakes or clutchbrake combinations from fractional through integral horsepower range for applications demanding close unidirectional or bidirectional control of torque at relatively highspeed levels. The potential of eddy current clutches is assessed from a representative case study consisting of a.
The kinetics svr1ec speedregulated, eddy current clutch field exciter is a scr regulated rectifier system specifically designed for the application of supplying regulated variable dc power, via a closed feedback loop system, to the field coil of an eddy current clutch adjustable speed drive. So if we look at an ac6000 compared to an ac4400, assuming the weight, traction motors and gear ratio are all the same, they are likely to haul the same load over a given. An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or onboard energy storage such as a battery or a supercapacitor electric locomotives with onboard fueled prime movers, such as diesel engines or gas turbines, are classed as dieselelectric or gas turbineelectric and not as electric locomotives, because the electric generatormotor. The name eunits refers to the model numbers given to each successive type, which all began with e.
The emd 645 family of diesel engines was designed and manufactured by the electromotive division of general motors. In 1912, william sherman brown, a locomotive engineer of the southern railway, patented the southern valve gear, and it was used extensively on southern locomotives. The eddy current clutch is usually tended to the small speed ratio no more than1030% speed reduction due to consideration of efficiency and cooling. However, unlike friction brakes, in which the drag force that stops the moving object is provided by friction between two surfaces pressed together, the drag force in an eddy current brake is an electromagnetic. Us electric wer eddy current parts electric maintenance. Resistance switching gives a steptype change in torque, and hence acceleration. Also a time dependent study was done to show the development of the same eddy currents in the disc with deceleration. An eddy current brake, also known as an induction brake, electric brake or electric retarder, is a device used to slow or stop a moving object by dissipating its kinetic energy as heat. At start up the maximum current flows through the motor, providing maximum torque. There are seven principal locomotive manufacturers and five major rail car car manufacturers in the united states. Figure 2 shows the schematic diagram of a simple eddy current brake with only one magnet around it. Emd eunits were a line of passenger train diesel locomotives built by the general motors electromotive division emd and its predecessor the electromotive corporation emc. Typical d motor drawbacks such as armature commutator damage, carbon tracking, frequent brush. After world war ii, the dieselization of american railroads was rapid.
The model name stands for broad gauge w, diesel d, mixed traffic m engine. The authors measured the brake forceair gap characteristics and compared the measured value with the calculated value. The first locomotive used was equipped with a rotary converter and dc traction motors 3. The class wdm3a is indian railways workhorse dieselelectric locomotive. For the most part, these locomotives are built to serve regional, niche markets with a very specific purpose. They were built by english electric and the new zealand railways department nzr between 1938 and 1940, and hauled mainly passenger trains on the wellington regions 1500 v dc electrification, and banked freight trains on the steep section between paekakariki and pukerua bay. Esr 0557 overhaul of eddy current clutch and gear box. The dieselelectric locomotive offered many advantages over its steampowered counterpart. An eddy current coupling 4 is proposed, with a first movable. The eddy current drive also called a magneticallycoupled adjustable speed drive, which consists of an eddy current clutch and associated controls, is favored for heavyduty applications with high starting torque and severe shock loads. Tractive effort versus horsepower trains magazine trains. A clutch that could pull this off would need to be huge, and generate a huge amount of heat and friction, needing extra weight for cooling and more maintenance.
The nominal air gap between inner and outer drum of ecc eddy current clutch is. Eddycurrent drives can produce more torque at low speed than an induction motor and vfd. Esr 0200 specification for the restoration of 48 class. For a given tractive effort, increased horsepower allows an increased speed with other things remaining the same. Technical challenges on the braking of highspeed trains. For me, the starting point for finding out more was this post in particular the posting by jim hardy contained lots of good links.
Its a complicated subject but very well studied in the context of eddy current brakes, where the retarding force is used to create a braking force without mechanical friction wear. Eddy current drives, also known generically as magnetic drives, eddy current clutches or magnetic clutches are driven at constant speed by an ac motor and utilize a simple electromagnetic device to control torque and speed to the driven load. From the following statements, can you identify those which are true or false concerning the electric system. Find types of eddy current clutch motor related suppliers, manufacturers, products and specifications on globalspec a trusted source of types of eddy current clutch motor information. The electrical drives used on trains have huge starting torque, and the torque profile stays relatively flat compared to a normal engine over its working range. In contrast to the drive and brake elements described previously, the torque in eddy current clutches and brakes fig. The nzr ed class locomotive was a type of electric locomotive used in wellington, new zealand. Dieselelectric locomotives introduction an understanding of the structure of a locomotive mechanically and electrically is essential to a person attempting to perform maintenance and repair services on it. Eddy current cutch daulat ram engineering serving railway. The first two numbers in the model designation is the weight 20 tons, the next two letters signify the enginedrive combination gas mechanical, and the final two numbers stand for a design number. Eddy current clutches give torque as a function of rpm. Pdf analysis of eddycurrent brakes for high speed railway.
The eaeb, e1, and e2 models were powered by twin 900 hp winton 201a v12 engines in each power unit. Voltmeters are connected to the high voltage side of the line. In a linear eddy current brake, the conductive piece is a straight rail or track that the magnet moves along. Ac drive is useful in locomotives that are worked at slow speeds with heavy torque, without overheating the motors.
Eddy current clutches or eddy current slip coupling are available in a broad range of sizes and speed up to thousands of kilowatts in both vertical and horizontal configurations. We provide repair services from 56 frame through 49 to 63. It also didnt require expensive support structures like roundhouses, coaling towers and water tanks. The companies featured in the following listing offer a comprehensive range of clutches. Electrical east central railways indian railways portal. The locomotive air compressor is connected to the radiator fan drive shaft by a rubber cushioned flexible rigid coupling. Eddy current drives can produce more torque at low speed than an induction motor and vfd. Request pdf design of an eddy current torque bypass clutch for seamless automated manual transmissions of electric and hybrid vehicles this paper. Eddy current clutch as well as fan coupling with eddy current clutch. When switching to a vfd for a constant torque load, the motor and the drive may require being oversized by a factor of 150% to 200%. Theory and applications article pdf available in proceedings of the ieee 8010. This procurement is also for all locomotive work needed to obtain tested locomotives, ready for operation when presented for final acceptance. The subsequent analysis is based on this simple model.
The brush grade used in ecc eddy current clutch is. However, unlike friction brakes, in which the drag force that stops the moving object is provided by friction between two surfaces pressed together, the drag force in an eddy current brake is an. Diagram 1 eddy current clutch and gearbox assembly 2 general this standard is to be used in conjunction with the manufacturers maintenance instructions, drawings and technical information, listed herein, for the respective eddy current clutch. Eddycurrent clutch article about eddycurrent clutch by. Specification for the restoration of 48 class locomotives esr 0200. Pdf a general analytical model of permanent magnet eddy. York specializes in services such as eddy current clutch repair. Available with 115230460 voltage, 16 hp and 14 hp motors and 1,700 rpm and 3,450 rpm speed. The physical working principle is the same for both. This book provides plenty of illustrations, photos, text and history that deals with the many aspects of this subject.
At lower engine temps, the fan was not turning, and the shutters were closed. The wdm3a is the most common diesel locomotive of indian railways. I bought an ho athearn genesis f3 ab set from a show. Figure 1 the control supplies dc voltage to the drive field coils and automatically varies drive excitation to maintain desired speed, torque, tension, position, or horsepower, as determined by the feedback signal. Tractive effort determines how much a locomotive can haul.
In a circular, disk or rotary eddy current brake, the conductor is a flat disk rotor that turns between the poles of the magnet. Welcome to the premier industrial source for clutches. If this seems far fetched, remember that modern prime movers use well over 3,000 horsepower to turn the generator to produce enough electricity to get the locomotive moving. Careful design consideration must be given to providing adequate cooling of both field coil and metallic drum. While the 645 series was intended primarily for locomotive, marine and stationary engine use, one 16cylinder version powered the 3319 titan prototype haul truck designed by gms terex division the 645 series was an evolution of the earlier 567 series and. Eddy current brakes are best substitutes for ordinary brakes, which are being used nowadays in road vehicles even in trains, because of their jerkfree operation. Electric propulsion controls and accessories a 77 a torque. An eddy current clutch would be highly controllable, simple to manufacture, lowcost, robust, and do not wear compared to friction clutches. This tach generator rotor fits some of the ed 40 and ed 41 frames from the us electric and wer eddy current clutches.
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