Eddy current brakes adjustable speed drives dynamatic. The variable speed drive shall be an eddycurrent coupling type magnetic drive, of aircooled open type construction. If playback doesnt begin shortly, try restarting your. The eddy current brake has a brake stator with at least one coil and a brake rotor with a brake region, wherein the brake region has a first layer which is electrically conductive and which has a first lateral face and a second lateral face, the first lateral. Dynamatic dcd models are direct nema and iec motor frame replacements for torspec brand models 100 tcd, 2 tcd, 160 tcd, 180 tcd and 225 tcd.
Electric vehicles evs with a singleratio gearbox may provide high levels of. Design of an eddy current torque bypass clutch for seamless. Esr 0557 overhaul of eddy current clutch and gear box. The potential of eddy current clutches is assessed from a representative case study consisting of a. A scalemodel fixture was used to test several different linear passive brakes based on neodymiumironboron ndfeb permanent magnets. Us10260571b2 clutch device with eddy current brake with.
There is no physical contact between motor and clutch. Apr 30, 2010 what is eddy current eddy currents are currents induced in conductors to oppose the change in flux that generated them. Eddy current clutch working, application, advantages and. For all types of coupling and brake the relevant efficiency. Eddy current braking is a state of the art braking technology that has both economic and risk management advantages. Eddy current drives utilize a design to maximize electronic response and operational efficiency. There are even nocontact clutches such as hysteresis clutch and eddy current clutch. The two major parts of the eddycurrent clutch are the drum assembly and the output rotor and shaft assembly.
Manual transmissions of electric and hybrid vehicles. This paper presents the design and experimental validation of an eddy current torque transfer clutch for use inside automated manual transmissions amts to perform seamless gear upshifts. Electromagnetic brakes electromagnetic brakes use electromagnetic circuit to implement mechanical blocking and hence ultimately use frictional force. We doesnt provide eddy current clutch products or service, please contact them directly and verify their companies info carefully. Nonfriction clutches, such as hysteresis, eddy current, and magnetic particle, often operate with continuous slip but can lock up if required torque is less than the clutch torque capacity. The principle of eddy current coupling makes it possi ble to obtain a wide range of stepless, adjustable speeds directly from industrial a. The clutch contains a fixed speed rotor and an adjustable speed rotor separated by a small air gap. Design and fabrication of an eddy current brake dynamometer for efficiency determination of electric wheelchair motors. The eddycurrent coupling or clutch is oldschool technology, but their robust design is appreciated by many. Request pdf design of an eddy current torque bypass clutch for seamless automated manual transmissions of electric and hybrid vehicles this paper. Part of the oil, gas, and energy commons, and the power and energy commons repository citation.
Design of an eddy current torque bypass clutch for. Electric wheelchairs have a considerable impact on improving the quality of life for the millions of disabled persons around the world. Dec 10, 2015 eddy current clutches eddy current clutches are so named because they in duce eddy currents into a metal cylinder or drum. 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.
Stromag is the leader in industrial brakes, couplings, clutches and controllers. This unique braking system takes the simple function of magnetic and nonmagnetic forces and turns it into a high tech masterpiece. What is eddy current eddy currents are currents induced in conductors to oppose the change in flux that generated them. The drive motor is started with no dc excitation to the clutch.
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. The armature or rotor is constructed so that when the winding is excited with direct current, magnetic pole pieces are formed. Introduction to brakes and different types of brake. This is the basis of eddy current testing, by monitoring the voltage across the coil in such an arrangement we can detect changes in the material of interest. Tech talk february 2011 eddy current drives holland industrial. Some common examples of brakes are water, eddy current and hydraulic. The medium of torque transmission is a controlled magnetic field, generated by a stationary. Kinetics eddy current clutch field exciter is a scr regulated rectifier system designed for the application of supplying regulated variable dc power. 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. Expired lifetime application number inventor max baermann original assignee max. The plant engineer also wanted to increase the torque output to the drawbench, improve overall drive. One part of the clutch contains slip rings and a winding figure 428a. The coils are excited with dc and attached to the mechanical load. We have created an eddy current brake which uses the same eddy current effect as an eddy current motor but is simpler to build.
Our technology the science of eddy current magnetic braking. Careful design consideration must be given to providing adequate cooling of both field coil and metallic drum. This is a handson seminar and laboratory experience about the engineering design of motorcycles. Timehonored and wellrespected manufacturers of eddy current dynamometers, were acquired by dyne systems in 2002. The function of an eddy current clutch is to transmit a controlled torque from the induction motor,prime mover to the load driven machine. This paper presents the design and experimental validation of an eddy current torque transfer clutch for use inside automated manual. The research outlined in this paper addresses the design of permanent magnet eddy current braking devices that can be utilized in vehicles, elevators and moving machinery of all sorts. Units are unaffected by friction and wear, therefore, torque is substantially more accurate and repeatable than friction tensioners.
Using these forces as a braking mechanism stems from the. When starting eddy current clutch operates at 100% slip allow the driver motor to accelerate. It is caused when a conductor is exposed to a changing magnetic field due to. Design and experimental demonstration of a seamless automated. The eddy current drive or clutch is a slip device consisting of two rotating elements that. The purpose of this book is to provide basic operating and technical information applicable to the eddy. In mountain areas where continuous braking force is needed, for a long time, the eddy current braking.
Im1600002004 dcd2 through 225 eddy current drives instruction manual revised february 18, 2004 drive source international, inc. Note that cracks must interrupt the surface eddy current flow to be detected. As carbon, steel tubes typically become heavily corroded during use and still be within their design tolerances it is not practical to detect small defects due to. Variable frequency drives and dc drives operate by electronically altering the input power to control the speed of the motor. The goal of this project is to eliminate using the physics of eddy currents.
Eddy current variable speed drive systems modern pumping today. Rated from 5 to 2,500 hp 4 to 1,864 kw wet and dry gap configurations. We hope to learn the effect of stator spacing, magnet size and shape, number of magnets, magnet radius, and phase angle have on braking force. Is it costeffective to replace old eddycurrent drives. An eddy current drive sometimes called a dynamatic drive, after one of the most common brand names consists of a fixed speed motor generally an induction motor and an eddy current clutch. Our simple, rugged eddy current design and selfcleaning rotor provides worryfree operation with no routine maintenance.
A threestory high 1,650 horsepower pump, 4,160 volt synchronous motor, and eddy current drive clutch at a wastewater treatment plant went in for its routine maintenance. We offer both aircooled and watercooled designs built with our reliable and durable eddy current technology for long service life. May 01, 2016 eddy current torque bypass clutch design representative design requirements the eddy current torque bypass clutch is designed for the allelectric volkswagen golf 2001 prototype. This webinar is intended to preserve the knowledge of how they work as well as their unique repair requirements. Real eddy current brakes are a bit more sophisticated than this, but work in essentially the same way. Eddy current brake design for operation with extreme back. An eddy current coupling 4 is proposed, with a first movable coupling. The eddy current clutch is usually tended to the small speed ratio no more than1030% speed reduction due to consideration of efficiency and cooling. 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. Eddy current clutch as well as fan coupling with eddy current clutch. 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.
Eddy current drive consists of a totally enclosed, fan. Eddy current definition of eddy current by the free dictionary. 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. Institute of physics publishing european journal of physics eur.
Eddy current drive consists of a totally enclosed, fan cooled tefc, flange type threephase squirrel cage induction motor is mounted on to an eddy current clutch, having a projected, selfventilated common frame design. Design and fabrication of an eddy current brake dynamometer for efficiency determination of electric wheelchair motors wesley brin wright state university follow this and additional works at. The squirrel cage rotor is attached to the driving motor. Eddy current definition of eddy current by the free.
Still other braking methods even transform kinetic energy into different forms, for example by transferring the energy to a rotating flywheel. After the motor has reached its target speed, its controller engages the eddy clutch. Eddy current brakes eddy current brakes use magnetic force directly for inhibiting the motion of the system. Eddy current drives can produce more torque at low speed than an induction motor and vfd. A set of simple experiments is proposed to measure eddy current losses and to relate them to various relevant parameters. Eddycurrent drives can produce more torque at low speed than an induction motor and vfd. Thus the transferable moment increases with the relative rpm. Figure 2 shows the schematic diagram of a simple eddy current brake with only one magnet around it. Because eddycurrent couplings and fluid couplings are uncommon, the institutional knowledge about them is being lost. Modelling and design of an eddy current coupling for slip.
Compact rugged physical solid state construction allows control and drive to be located in adverse environments with reliable operation. However, most widely used form is single face friction clutch. The subsequent analysis is based on this simple model. The variable speed drive shall be an eddy current coupling type magnetic drive, of aircooled open type construction. The setup operates like an eddy current brake, a device commonly used in heavy vehicles to dissipate kinetic energy by generating eddy currents. The methods of the analytical and numerical loss calculation are known essentially 3 and are permanently developed further. Engineered for the demands of heavy industry, companies in sectors from transportation, energy, oil drilling, steel, shipping and more depend on stromag equipment and replacement parts to keep operations running and safe. The braking is frictionfree with no contacting parts. The invention comprises a clutch device having an actuating device, wherein the actuating device has an electrical eddy current brake. 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.
The ability to hold at constant rpm whilst you vary the engines load point control the throttle is. Design and fabrication of an eddy current brake dynamometer. Our eddy current brake technology is extremely reliable, smooth, and low maintenance. Eddy current drive is a combination of a constant speed ac induction motor, coupled to an eddy current clutch. Dynamatic adjustable speed drives, brakes and controls oem.
Keywords brakes, comsol multiphysics, eddy current. As carbon, steel tubes typically become heavily corroded during use and still be within their design tolerances it is not practical to detect small defects due to the high background noise levels. Permanent magnet electrodynamic brakes design principles. In contrast to the drive and brake elements described previously, the torque in eddy current clutches and brakes fig. Eddy current torque bypass clutch design representative design requirements the eddy current torque bypass clutch is designed for the allelectric volkswagen golf 2001 prototype. Each magnetic clutch shall consist of a stationary frame, a ring member driven at motor speed, and a variable speed member, bearings, outer bearing bracket and housing, heat exchanger if recommended by the manufacturer, motor. Request pdf design of an eddy current torque bypass clutch for seamless automated manual transmissions of electric and hybrid vehicles this paper presents the design and experimental. Drive source international dsi is the worlds leading manufacturer of eddy current adjustable speed drives, brakes and controls. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.
The electromagnetic clutch comes various forms, including magnetic particle clutch and multidisc clutch. The drive unit consists of a constant speed induction motor and an integral magnetic clutch, or eddy current coupling, assembled in a common housing. Pet permanentmagnet eddycurrent clutchbrake tkk corporation. Us3488535a permanent magnet eddy current brake or clutch. Blog 5 applications of eddy current brakes head rush. The thermal load on the power distribution system theref ore needed to be reduced to prevent the frequent overload trips.
The art and science of motorcycle design michael littman. Eddy current brakes use magnetic fields to convert kinetic energy into electric current in the brake disc, fin, or rail, which is converted into heat. It is currently equipped with a twospeed amt without torque fillin capability during gearshifts. An eddy current clutch would be highly controllable, simple to manufacture, lowcost, robust, and do not wear compared to friction clutches. Dynamatic adjustable speed drives, brakes and controls. Eddy current clutches eddy current clutches are so named because they in duce eddy currents into a metal cylinder or drum. Other specialized motors ac motors electronics textbook. These parameters have been previously iterated in cited projects and papers and also in the simulation models and are to be crosschecked with the experimental setup. They are an adjustable speed drive and provide soft starting capability.
Huge energy savings potential operating centrifugal fans, pumps and compressors vary frequency of electrical supply to an induction motor to vary the motor speed. Eddycurrent clutches consist of a field, ta chometer, and eddycurrent control. Electromagnetic clutch working, applications, advantages. If the stator of an induction motor or a synchronous motor is mounted to rotate independently of the rotor, an eddy current clutch results. At that time, the municipality replaced their outdated analog controlling system for the eddy current clutch to a new digital dynamatic ec2000 high power clutch controller. There is an air gap present to prevent mechanical transmission of torque. 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. Pdf design and experimental demonstration of a seamless. Design and experimental demonstration of a seamless.
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