York specializes in services such as eddy current clutch repair. When starting eddy current clutch operates at 100% slip allow the driver motor to accelerate. Eddy current drives for industrial automation dynaspede. Eddy current clutches the regutron 3 dcrs digital speed control is a costeffective way to upgrade existing analog eddycurrent clutch controllers. Drive source international dsi is the worlds leading manufacturer of eddy current adjustable speed drives, brakes and controls. Eddycurrent clutches consist of a field, ta chometer, and eddycurrent control. The inductor includes a plurality of pole shoes of alternating magnetic polarity arranged in an annular ring and a plurality of permanent magnets disposed. Eddy current drive is a combination of a constant speed ac induction motor, coupled to an eddy current clutch.
The drive motor is started with no dc excitation to the clutch. 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. The coils are excited with dc and attached to the mechanical load. Calculation methods for eddy current losses at the example of a permanent excited synchronous machine inside the threshing cylinder of a combine harvester abstract. Thus the transferable moment increases with the relative rpm. Other specialized motors ac motors electronics textbook. Seamless gearshift measurement figure 16 shows a complete upshift sequence using the eddy current clutch with a constant 16adc excitation current in the clutch electromagnet.
Figure 2 shows the schematic diagram of a simple eddy current brake with only one magnet around it. Dm advantage twospeed fan speed over time with dm advantage. Long stator end effects could be modeled by simply modeling the entire length of the plate in the present style of analysis, adding a few extra wavelengths of stator on either side of. The drive motor, with a full load amp r ating of 250 amps, was at times drawing over 900 amps. An eddy current andor induction brake or clutch comprised of, a braking inductor and a ferromagnetic eddy current conductor arranged for relative rotation with respect to one another. Variable frequency drives vfds popular speed control devices used in industrial, commercial. They are an adjustable speed drive and provide soft starting capability.
Eddycurrent clutches and fluid couplings upcoming seminars. Stromag sas unit 87 rocco drive victoria 3179telfax. Design and experimental demonstration of a seamless. The principle of eddy current coupling makes it possi ble to obtain a wide range of stepless, adjustable speeds directly from industrial a. Request pdf design of an eddy current torque bypass clutch for seamless automated manual transmissions of electric and hybrid vehicles this paper. While full braking torque is possible independent of slip speed, eddycurrent effects can increase the dynamic braking torque over a static calibrated value by as much as 7% to 8% per rpm increase in speed. Eddy current brake design for operation with extreme back. This easytooperate controller provides standalone control of a single magnetic drive or accurate coordination of more complex multidrive systems such as series pump applications.
A slight eddycurrent effect is present in a hysteresis brake or clutch. The braking is frictionfree with no contacting parts. After the motor has reached its target speed, its controller engages the eddy clutch. Medical imaging equipment, water handling systems, conveyors, robotic systems and rotary and linear actuators are among the many devices that may be fitted with electric friction brakes to hold their loads in place when the power is off. Eddycurrent clutch article about eddycurrent clutch by. Couplings couplings for metalrolling mills b21b 3514. Diagram 1 eddy current clutch and gearbox assembly 2 general. High quality eddy current testing solutions for complete inspections. Our eddy current brake technology is extremely reliable, smooth, and low maintenance. The eddy current clutch acts as a rotating transformer similar to a motor. Huge energy savings potential operating centrifugal fans, pumps and compressors vary frequency of electrical supply to an induction motor to vary the motor speed. Variable frequency drives and dc drives operate by electronically altering the input power to control the speed of the motor. After that the reaction by eddy currents doesnt play a role in the iron because of the use of thin laminated sheet steel and in the magnets because of the little conductance, but it has to be taken into account in construction elements. In the eddy current clutch, a static dc current produces a magnetic field in the air gap, coupling the rotating input drum and the output rotor.
The input shaft directly coupled to the motor and variable speed output shaft is connected to load. The plant engineer also wanted to increase the torque output to the drawbench, improve overall drive. The design procedure is based on a torque formula derived from a 3d analytical model and a. The clutch contains a fixed speed rotor and an adjustable speed rotor separated by a small air gap. May 01, 2016 possible improvements of the eddy current clutch include the use of steel with a higher saturation level for the stator and the doubly toothed rotor.
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. Sort by date 1 controlling backlash in mammography systems. Eddycurrent drives can produce more torque at low speed than an induction motor and vfd. Design optimization of an axialfield eddycurrent magnetic coupling. We have the most extensive experience, and we develop the highest quality ect inspection products. The companies featured in the following listing offer a comprehensive range of clutches. Eddy current, as well as a variety of related products and services. 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. In contrast to the drive and brake elements described previously, the torque in eddy current clutches and brakes fig. A slight eddy current effect is present in a hysteresis brake or clutch.
Eddy current clutch working, application, advantages and. A basic analysis of a long stator eddy current brake has been presented in this notebook. The prototype performed a seamless shift on a test bench demonstrating the viability of using an eddy current clutch for torque bypass clutches in amts. 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%. Design of an eddy current torque bypass clutch for. We can repair your minster machine co scrb52 in our facility. An eddy current clutch ecc drive is a device used to convert constant speed rotation input into adjustable speed output. Our commitment to innovation and quality doesnt end at engine parts.
While full braking torque is possible independent of slip speed, eddy current effects can increase the dynamic braking torque over a static calibrated value by as much as 7% to 8% per rpm increase in speed. Let our skilled technicians get your cyclemite eddy current clutch control back in operation quickly. The specific loss factor pwb for eddy current losses is. Design and experimental demonstration of a seamless automated. Esr 0557 overhaul of eddy current clutch and gear box. The eddy current coupling or clutch is oldschool technology, but their robust design is appreciated by many. A set of simple experiments is proposed to measure eddy current losses and to relate them to various relevant parameters.
Tech talk february 2011 eddy current drives holland industrial. Eddycurrent clutches and fluid couplings trade press. Us3488535a permanent magnet eddy current brake or clutch. The two major parts of the eddycurrent clutch are the drum assembly and the output rotor and shaft assembly. One part of the clutch contains slip rings and a winding figure 428a. 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. Eddy current clutch hydrostatic drives wound rotor motor dc drives. Variable frequency drives vfds popular speed control devices used in industrial, commercial and residential applications.
The squirrel cage rotor is attached to the driving motor. 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. 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. Because eddy current couplings and fluid couplings are uncommon, the institutional knowledge about them is being lost. Step 2 print the rma form and put it in a box with the parts for repair. The eddy current clutch prototype doesnt meet the torque requirement of 193 nm on the slip speed range see table 3, because of clutch geometric constraints imposed by the retro fit. Is it costeffective to replace old eddycurrent drives. An eddy current coupling 4 is proposed, with a first movable coupling element. Possible improvements of the eddy current clutch include the use of steel with a higher saturation level for the stator and the doubly toothed rotor. Our technology the science of eddy current magnetic braking. Eddy current variable speed drive systems modern pumping today. The inductor includes a plurality of pole shoes of alternating magnetic polarity arranged in an annular ring and a plurality of permanent magnets disposed intermediate the pole shoes. The medium of torque transmission is a controlled magnetic field, generated by a stationary. Therefore electrical drives become more and more interesting also for.
Stromag is the leader in industrial brakes, couplings, clutches and controllers. 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. They are available in standard and high speed models with many speed and torque versions. Dynamatic adjustable speed drives, brakes and controls oem. Us3488535a us3488535da us3488535a us 3488535 a us3488535 a us 3488535a us 3488535d a us3488535d a us 3488535da us 3488535 a us3488535 a us 3488535a authority us united states prior art keywords eddy current pole magnets permanent magnet flux prior art date 19670922 legal status the legal status is an assumption and is not a legal conclusion. Eddy current clutches the regutron 3 dcrs digital speed control is a costeffective way to upgrade existing analog eddy current clutch controllers. Current hub bearing deepgroove bearings 9 rolling elements per row low load capacity not preloaded size. The setup operates like an eddy current brake, a device commonly used in heavy vehicles to dissipate kinetic energy by generating eddy currents. Minster machine co scrb52 cyclemite eddy current clutch control. This webinar is intended to preserve the knowledge of how they work as well as their unique repair requirements. Eddy current drives can produce more torque at low speed than an induction motor and vfd.
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. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. The armature or rotor is constructed so that when the winding is excited with direct current, magnetic pole pieces are formed. Dynamatic eddy current drivesbrakes heco all systems go. As an application engineering manufacturer, dynamatic offers the most complete line of electromagnetic drives, brakes, and digital controls, centered on the worldrenowned dynamatic brand. 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.
An eddy current clutch would be highly controllable, simple to manufacture, lowcost, robust, and do not wear compared to friction clutches. Eddycurrent systems, control drives stromag pdf catalogs. Weve created a new line of clutches for some of the most popular tractor models in the industry. In mountain areas where continuous braking force is needed, for a long time, the eddy current braking. Eddy current transmission drive kingstone model works. The function of an eddy current clutch is to transmit a controlled torque from the induction motor,prime mover to the load driven machine. Us3601641a eddy current andor induction brake or clutch. 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. Kinetics eddy current clutch field exciter is a scr regulated rectifier system designed for the application of supplying regulated variable dc power. 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 clutches articles about eddy current clutches.
Pdf design and experimental demonstration of a seamless. Zetec is the industry leader for costeffective eddy current testing ect in complex applications. The drive unit consists of a constant speed induction motor and an integral magnetic clutch, or eddy current coupling, assembled in a common housing. Reliance brand clutch discs are made from the strongest materials for your tractor application. Our eddy current dynos are simple, cost effective, torque measuring devices for a large range of test purposes. Minster machine co scrb52 cyclemite eddy current clutch. The subsequent analysis is based on this simple model. The eddycurrent drive or clutch is a slip device consisting of two rotating elements that are coupled by a magnetic field.
The function of an eddy current clutch is to transmit a controlled torque from the induction motor,prime mover to the load. Head rush is the only company to use magnetic eddy current braking technology in climbing, free fall, and zip line devices, and the difference shows. Eddy current clutches articles, news and companies. If playback doesnt begin shortly, try restarting your.
Expired lifetime application number inventor max baermann original assignee max. Affiliated distributors applied power solutions bearing headquarters dalton bearing service, inc. The eddycurrent coupling or clutch is oldschool technology, but their robust design is appreciated by many. Eddy current clutches eddy current clutches are so named because they in duce eddy currents into a metal cylinder or drum. Dynaspede offers a comprehensive range of eddy current clutches, brakes or clutch brake combinations from fractional through integral horsepower range for applications demanding close unidirectional or bidirectional control of torque at relatively highspeed levels. The primary elements of eddy current variable speed drive are an ac motor, an eddy current clutch, a tacho generator and a seperate small solidstate electronic. The eddy current drive or clutch is a slip device consisting of two rotating elements that. Welcome to the premier industrial source for clutches. Eddy current clutches articles, news and companies related. New electrical drive concepts make it possible to put a high functionality into a restricted structural form. The pole geometry of the coupled output member imprints a pattern of alternating magnetic domains on the drum. In the basic form, the eddy current drive consists of an ac motor and an electrically controlled magnetic clutch. We provide repair services from 56 frame through 49 to 63. An eddy current drive, also known generically as a magnetic drive, eddy current clutch or magnetic clutch, is an electromechanical variable speed drive that.
Design of an eddy current torque bypass clutch for seamless. Also a time dependent study was done to show the development of the same eddy currents in the disc with deceleration. The potential of eddy current clutches is assessed from a representative case study consisting of a. The thermal load on the power distribution system theref ore needed to be reduced to prevent the frequent overload trips. Eddy current drive consists of a totally enclosed, fan cooled tefc.
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