The armature or rotor is constructed so that when the winding is excited with direct current, magnetic pole pieces are formed. Eddy current sensor operates based on the inductive eddy current principle. 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%. The annual energy consumption of the existing system or eddy current baseline is calculated in table 2. Typically, we rate the clutch with a gain factor k, which is gram millimetersrpm or newton metersrpm and we design the clutch to have an operating. 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.
Eddy current clutch as well as fan coupling with eddy current clutch. 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. The drive unit consists of a constant speed induction motor and an integral magnetic clutch, or eddy current coupling, assembled in a common housing. The eddy current method is widely used to inspect metallic aircraft components for surface cracks and corrosion damage. Products sold, serviced, maintained, and retrofitted by emicc. When starting eddy current clutch operates at 100% slip allow the driver motor to accelerate. 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. This means by increasing or decreasing the rpm, you can get infinite torque adjustment. Zetec is the industry leader for costeffective eddy current testing ect in complex applications.
Sep 01, 2011 hp eddy current clutch full load test electricaltest2011. Electromagnetic clutches and couplings sciencedirect. The companies featured in the following listing offer a comprehensive range of clutches. 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. The potential of eddy current clutches is assessed from a representative case study consisting of a.
This opposing torque is used to brake the automobiles. It measures the distance based on the extraction of energy from an oscillating circuit, which is required to generate eddy current in an electricallyconductive materials. Determining eddy current coupling losses electric motors. Sort by date 1 controlling backlash in mammography systems. In other words, the rotation of the eddy current clutch assembly 6 generates eddy currents in the inductor segments 33, 34 and 35 resulting in a driving torque being created which operates to rotate and drive the clutch rotor assembly 29 at a speed which is less than that of the clutch assembly 6. The test equipment consists of a generator ac power supply, a test coil and recording equipment, e.
Us3488535a permanent magnet eddy current brake or clutch. As the eddy current drive efficiency drops rapidly at loads below 70%, energy savings are extremely sensitive to the load profile and duty. The input shaft directly coupled to the motor and variable speed output shaft is connected to load. The setup operates like an eddy current brake, a device commonly used in heavy vehicles to dissipate kinetic energy by generating eddy currents. Eddy current, as well as a variety of related products and services. 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. Eddy current clutches are driven at a constant speed by an ac induction motor. A stationary study was done to evaluate the eddy current generated in the disc.
In contrast to the drive and brake elements described previously, the torque in eddy current clutches and brakes fig. Note that cracks must interrupt the surface eddy current flow to be detected. Induced electromotive force is produced in the coil when there is a change in the magnetic flux linked with that coil. Eddy current brakes work much the same way, except that one of the torque transmitting members is rigidly attached to the casing and is thus held stationary. How eddy current clutches work eddy current clutches give torque as a function of rpm. Downloaded from sae international by ithakajstor, sunday, june 11, 2017. The current will vary up and down with the voltage. Dynamatic mark iii eddy current control eddy current drive. We offer both aircooled and watercooled designs built with our reliable and durable eddy current technology for long service life.
One part of the clutch contains slip rings and a winding figure 428a. Request pdf design of an eddy current torque bypass clutch for seamless automated manual transmissions of electric and hybrid vehicles this paper. Electromagnetic brakes electromagnetic brakes use electromagnetic circuit to implement mechanical blocking and hence ultimately use frictional force. Figure 2 shows the schematic diagram of a simple eddy current brake with only one magnet around it. The current generates a magnetic field around the coil. Eddy current is the swirling current produced in a conductor, which is subjected to a change in magnetic field. These circulating currents are called eddy currents. When a conductor is placed in the changing magnetic field, the induced current in the conductor is termed as eddy currents. As these currents are not responsible for doing any useful work, and it produces a loss i 2 r loss in the magnetic material known as an eddy current loss. Electromagnetic clutches and couplings contains a detailed description of u. Eddy current brakes adjustable speed drives dynamatic. Dynamatic offers a wide range of eddy current brakes engineered to meet your needs.
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. Ectane 2 e, ectane 2 e64, ectane 2 e128, ectane 2 e256, ectane 2 i, ectane 2 ernm, ectane 2. Weve created a new line of clutches for some of the most popular tractor models in the industry. Capelec universal tachometer installing the easy rpm 54. An eddy current coupling 4 is proposed, with a first movable coupling element comprising. Such a device therefore can exert a controlled braking torque, when the brake shaft is externally driven. The rotor rotates with the help of the prime mover shaft and the voltage is applied to the coil or stator housing. Drive source international dsi is the worlds leading manufacturer of eddy current adjustable speed drives, brakes and controls. They are an adjustable speed drive and provide soft starting capability. Eleven series of clutches perform three basic modes of operation.
The ac motor interacts with an electromagnetic clutch that controls both the. An eddy current clutch and an induction machine are identical in working principle. Eddy current brakes must have a slip between the rotor and the stator to generate torque. Because eddy current couplings and fluid couplings are uncommon, the institutional knowledge about them is being lost. Esr 0557 overhaul of eddy current clutch and gear box. Mechanical clutches the industrys broadest line of conveyor backstop, overrunning and indexing clutches. Similar to hysteresis loss, eddy current loss also increases the temperature of the. 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. Eddy current clutches give torque as a function of rpm. Eddy current technique is an important electromagnetic nondestructive evaluation technique. View and download eddyfi ectane 2 user manual online. Jan 03, 20 s eddy current brakes, like conventional friction brakes, are responsible for slowing an object, such as rotating machinery, amoving train, or even a roller coaster.
Eddy current clutches articles, news and companies related. Eddycurrent drives can produce more torque at low speed than an induction motor and vfd. They will occur when the conductor experiences a changing magnetic field. This webinar is intended to preserve the knowledge of how they work as well as their unique repair requirements. Dec 10, 2015 eddy current clutches eddy current clutches are so named because they in duce eddy currents into a metal cylinder or drum. Isc companies magnetic technologies ltd mayr corporation motion industries. Get more information about eddy current brakes pdf download by visiting this link. Eddy current drive is a combination of a constant speed ac induction motor, coupled to an eddy current clutch. Eddy current drives can produce more torque at low speed than an induction motor and vfd. Magnetic technologies brakes, cluthces and couplings. Our commitment to innovation and quality doesnt end at engine parts. A set of simple experiments is proposed to measure eddy current losses and to relate them to various relevant parameters. 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.
The drawbacks of ordinary brakes which uses mechanicalblocking could be eliminated by use of a more simple andeffective. 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. Electronic system for nondestructive testing using eddy. There is an air gap present to prevent mechanical transmission of torque. 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 dynamometer working principle powerlink.
This linking generates eddy currents in the driven rotor. Eddycurrent clutches and fluid couplings trade press. This paper presents the design and experimental validation of an eddy current torque transfer clutch for use inside automated manual. Expired lifetime application number inventor max baermann original assignee max. Eddy current brake design for operation with extreme back. It uses electromagnetic fialds and is very aenaitive to many material and geomet. 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. Repairsservice to electric machinery synchrostatic field application controls. Also a time dependent study was done to show the development of the same eddy currents in the disc with deceleration. Hysteresis brakes and clutches a slight eddy current effect is present in a hysteresis brake or clutch. Pet datasheet11 pages etc pm eddycurrent torque controller. These brakes make use of opposing tendency of eddy currents. Eddy current testing can be used on all electrically conducting materials with a reasonably smooth surface. Eddy current dynamometer working principle the powerlink eddy current dynamometer measures the torque and power of the prime mover motor or engine.
Eddy current clutches articles about eddy current clutches. Eddy current clutches eddy current clutches are so named because they in duce eddy currents into a metal cylinder or drum. 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. Thus the transferable moment increases with the relative rpm. Design of an eddy current torque bypass clutch for. Permanent magnet pm eddy current torque controllertypes. They are available in standard and high speed models with many speed and torque versions. 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. Pdf design and experimental demonstration of a seamless. Mainly this system is purely based on faradays laws of electromagnetic induction and lenzs law. Is it costeffective to replace old eddycurrent drives. The clutch design is based upon wouterses model, which is. Eddy current dynamometers dynos providing precise control and low maintenance. Affiliated distributors applied power solutions bearing headquarters dalton bearing service, inc.
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. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Eddy current transmission drive kingstone model works. Instruction manuals for yaskawa legacy eddy current product called the vs motor as in. Eddy current clutch working, application, advantages and. The eddy current coupling or clutch is oldschool technology, but their robust design is appreciated by many. Eddy current clutches articles, news and companies.
We have the most extensive experience, and we develop the highest quality ect inspection products. An eddy current clutch relies on electromagnetic forces to create a. The system based on the ecscan architecture makes use of a new probe excitation block capable of simultaneously. 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. A simple engineering tool to evaluate eddy current phenomena in ferromagnetic bodies of regular shapes laminations, rods, cylinders is the physical cauer circuit cc, which is a ladder. Welcome to the premier industrial source for clutches. 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. We provide repair services from 56 frame through 49 to 63. Eddy current testing equipment contains a conductive metal coil which is electrified with an alternating current.
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. The principle of eddy current coupling makes it possi ble to obtain a wide range of stepless, adjustable speeds directly from industrial a. High quality eddy current testing solutions for complete inspections. Apr 01, 2014 eddy current brakes eddy current brakes use magnetic force directly for inhibiting the motion of the system. Below you will find the available manuals, install guides, software guides, software and updates for your 248 automotive dynamometer. The function of an eddy current clutch is to transmit a controlled torque from the induction motor,prime mover to the load driven machine. Clutch brake units have an eddy current brake in addition to a clutch. The eddycurrent drive or clutch is a slip device consisting of two rotating elements that are coupled by a. Design of an eddy current torque bypass clutch for seamless. A formulation of the eddycurrent problem in the presence. Seminar on eddy current brake report pdf download abstract this is an electric braking system which works on the principle that eddy current produced in it opposes the driving torque. Repairsservice to electric machinery synchronex excitation units. An eddy current andor induction brake or clutch comprising. Repairsservice to electric machinery regutron eddy current clutch controllers.
Physical cauer circuits in nonlinear eddycurrent modeling. If you need help with your 248 dynamometer, please contact our 248 dynamometer customer support team. The subsequent analysis is based on this simple model. Eddycurrent clutch article about eddycurrent clutch by. Eddy current clutch repair heco all systems go heco inc. The medium of torque transmission is a controlled magnetic field, generated by a stationary. Eddycurrent clutches and fluid couplings upcoming seminars. The physical interpretation and computational effectiveness of ladder electric networks often make them preferable to more universal but costly finite element methods.
The aim of this project is to develop an electronic system that makes use of multiplexing techniques applied to eddy current nondestructive testing while using a new probe array. York specializes in services such as eddy current clutch repair. The eddy current drive or clutch is a slip device consisting of two rotating elements that. Ectane 2 measuring instruments pdf manual download. Overrunning indexing backstopping these units have set standards of. Eddy currents are named so because the current looks like eddies or whirlpools. Rao nondestructive evaluation division metallurgy and materials group indira gandhi center for atomic research kalpakkam 603 102, tn, india email. Hp eddy current clutch full load test electricaltest2011. The eddy current clutch control system was a mechanical electrical means of providing variable speed control of a.
Morse mechanical clutches offer the most complete and versatile selection in the industry. An eddy current brake having an electromagnetic pole and the rotor is positioned in close proximity to the stator with an air gap between them 9. Our eddy current dynos are simple, cost effective, torque measuring devices for a large range of test purposes. Eddy current drive replacement f3n2cec control techniques.
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