Eddy current controls flexible and precise control options for all your adjustable speed drives and brakes. Pdf a general analytical model of permanent magnet eddy. Drive motor totally enclosed fan cooled ic4180415 volts 3 phase 50 hz other supplies on request highest quality insulation system utilizing class h and f materials. Eddy current variable speed drive systems modern pumping. Eddy current is the swirling current produced in a conductor, which is subjected to a change in magnetic field. The drives are available in ranges from 2 to 200 hp and are used in a. 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 green machine eddy current separators are designed to automatically separate and sort nonferrous metals such as aluminum cans from a mixed materials waste stream. Whether testing small electric tools, large electric motors, offroad diesel engines, marine diesel engines or powertrain components, we have a system thats.
Esr 0557 overhaul of eddy current clutch and gear box. Interaction between the stator field and eddy currents produces a torque which causes rotor to move with stator with a slip. After the motor has reached its target speed, its controller engages the eddy clutch. Eddy current brake design for operation with extreme. Eddy current sensor noncontact sensor designed for critical turbomachinery applications such as steam, gas and hydro turbines, compressors, gearboxes, pumps and fans to measure radial and axial shaft dynamic displacement. Diagram 1 eddy current clutch and gearbox assembly 2 general. Like the pumps and electric motors that drive them, eddy current drives are rotating machines.
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. Us5149998a eddy current drive dynamic braking system for. An eddy current drive, also known generically as a magnetic drive, eddy current clutch or magnetic clutch, is an electromechanical variable speed drive that. Eddycurrent clutches consist of a field, ta chometer, and eddycurrent control. There is no mechanical linkage between input and output members of the drive. Eddy current variable speed drive systems modern pumping today.
Eddy current drives power 312014 we are a force to reckon with in offering a large range of eddy current drives which are preferred as they have traits such as need minimum maintenance, available in power range of 1hp to 120 hp with variety of applications and also find applications in speed or torque control operations. To determine which eddy current controller model can be used with your mechanical unit, please refer to the dynamatic controllers catalog section for the drivecontroller compatibility and selection chart. Dynamatic eddy current drivesbrakes heco all systems go. How dynamatic technology works adjustable speed drive system. The work of this section includes providing eddycurrent variable speed drive units with. Eddycurrent loss and temperature rise in the formwound stator winding of an inverterfed cage induction motor article in ieee transactions on magnetics 468. Eddycurrent loss and temperature rise in the formwound.
Variable frequency drives vfds popular speed control devices used in industrial, commercial and residential applications. Pulse width modulated variable frequency drives 27 4 selection of vfd drives 31 a. Eddycurrent systems, control drives stromag pdf catalogs. Dsidynamatic is a manufacturer of dynamatic brand products, parts and services that stocks thousands of products and parts, including eddycurrent drives, factorywarrantied replacement parts. 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. Is it costeffective to replace old eddy current drives. Streicher rockwell automation mequon wisconsin quite often, line and load reactors are installed on ac drives without a solid understanding of why or what the positive and negative consequences are for adding this piece of hardware. Since there is no contact with a brake shoe or drum, there is no mechanical wear. Drive source international dsi is the worlds leading manufacturer of eddy current adjustable speed drives, brakes and controls. Eddy current clutch hydrostatic drives wound rotor motor dc drives. And these current in return produces a loss called eddy current loss or i 2 r loss, where i is the value of the current and r is the resistance of the eddy current path. Energy loss due to eddy current in linear transformer driver ltd cores.
The drive unit consists of an ac induction motor driving the input member or fan pole assembly of the magnetic drive. There are three general categories of electric drives. Dc motor drives, eddy current drives and ac motor drives. In a typical vertical configuration, shown in image 3, an ordinary induction motor is mounted atop the eddy current drive. Dynamatic motors adjusto spede at drives ces drives. These magnets rotate at a high rate of speed to create what is called an eddy field. Pdf determination of the effect of conductive disk thickness on. Principal eddy current component is related to roll movement as it depends on rate of change of external field which is the highest for roll. This manual generally covers all model numbers beginning with the letters dcd, followed by a hyphen and a number between 2 and 225, and ending with a hyphen followed by a number between 4041 and 4181. Mechanical speed control 24 3 principles of operation ac vfd drives 25 a. With the help of feedback controller an eddy current coupled speed drive can be achieved. Electrical current passes through coils surrounding the disk, and induce a magnetic resistance to the motion of the disk. Variable speed drives an overview sciencedirect topics.
Eddy current separators green machine recycling equipment. The engine being tested spins a disk in the dynamometer. Torspec internationals eddy current brakes, variable speed drives and controls continue to prove the quality in our simple rugged reliable design. Heavyduty, ac dynamometers dynos ac dynamometers dynos provide accurate and repeatable dynamometer control under stringent operating conditions for various testing applications. 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.
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. Eddycurrent drives can produce more torque at low speed than an induction motor and vfd. The pole geometry of the coupled output member imprints a pattern of alternating magnetic domains on the drum. Pdf in eddy current brakes, mechanical energy is converted into thermal energy and the system is mainly an electromechanical conversion. Carotron now offers products by drive source international, inc. It detects present of metals inside rocks, soils etc. 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. A dynamic braking means for a variable speed dynamoelectric eddy current drive consists of an ac motor 4 rotationally coupled through a shaft 6 to an inductor drum assembly of an eddy current coupling 3, where an annular field coil 12 generates an electromagnetic field which couples the inductor drum assembly to a pole assembly 10 which is rotationally coupled to an output shaft. An eddy current drive controls speed by regulating a directcurrent dc excitation coil on a magnetic rotor, rotating concentrically with a steel drum, driven by the motor at full speed. Eddy current drives advantages of eddy current drives. Dynamatic dcd drives eddy current drive by drive source international, inc. Eddy current adjustable speed drives design features the following figuresofmerit may be compared for an objective study of eddy current drives of different brands.
Electromagnetic eddy current engineering is simply better by design. Eddy current dynamometers are electromagnetic load devices. Capacitors are usually classified, according to their dielectrics, as air capacitors, mica capacitors, paper capacitors, etc. Performance 5mm sensor linear measurement range 1 mm 40 mils initial air gap 0. Kinds of drive ac drives dc drives variable frequency drives variable speed drives adjustable. For the best value on new electrical servo and industrial motors, call us at 5864690710. Eddy current and fluid couplings exhibit fixed slip loss rang ing trcrm 2 to this means highest attainable efficiency is only 9598% with correspond ng maximum attainable output speed d 9598% 01 input speed, unlike eddy current and fluid ccup. Dynamatic dcd drives eddy current drives eddy current. Whether you need a standard motor control product dc drives, dinrail modules, etc. The eddy current drive is built within a stationary frame of fabricated or cast steel, with a lower flange and shaft similar to that of a vertical motor. However, an eddy current brake cannot provide a holding torque and so may be used in combination with mechanical brakes, for example, on overhead cranes.
An eddy current drive controls speed by regulating a direct current dc excitation coil on a magnetic rotor, rotating concentrically with a steel drum, driven by the motor at full speed. Dynamatic offers a complete line of eddy current variable speed drives up to 4,000 hp, air and liquidcooled eddy current brakes, and related controls. Electronic pulsewidthmodulated pwm variable frequency drives vfd may be costeffective replacements for aging or highmaintenance eddy current drives that are used with variable torque loads, such as centrifugal fans or pumps. The separators work by utilizing a system of rare earth magnets. Variable frequency drives and dc drives operate by electronically altering. Consult stromags entire eddy current systems, control drives catalogue on directindustry. Owing to their precise design and high efficiency, these products are used for maintaining constant torque application for variable load. A sourcebook for industry v capacitor a device, the primary purpose of which is to introduce capacitance into an electric circuit. Maximum sensitivity is obtained with this control set fully clockwise. Eddycurrent coupling as an industrial variablespeed drive.
Powermag is the authorised system integrator of all kind of automation products from ac motors to soft starters, ac drives, ac servo motion control systems, plc, hmi, dcs, sensors, transducers and control panels. To determine which eddy current controller model can be used with your mechanical unit, please refer to the dynamatic controllers catalog section for the drive controller compatibility and selection chart. Eddy current drives are induced in rotor drum by stator magnetic field. It finds applications in metal forming, conveyors, plastic processing etc.
Tech talk february 2011 eddy current drives holland industrial. The eddy current clutch acts as a rotating transformer similar to a motor. Eddy current drive acpl eddy current drive manufacturer. An eddy current drive system consists of ac motor and eddy current coupling, a control and operators control station. We have emerged as prominent manufacturer, exporter and supplier of acpl eddy current drive. Torspec international inc eddy current brakes manuals. Eddy current drive consists of a totally enclosed, fan cooled tefc. The eddycurrent drive or clutch is a slip device consisting of two rotating elements that. Slip, and therefore, the load speed, can be controlled by controlling dc current through stator winding.
Get more information about eddy current brakes pdf download by visiting this link. Eddy current controls adjustable speed drive controls. Eddy current brakes use the drag force created by eddy currents as a brake to slow or stop moving objects. Harsh environments such as asphalt and aggregate duty are no problem for the dependable and reliable performance of dynamatic dcd drives. Pdf energy loss due to eddy current in linear transformer. Browse available downloads by product group and product line or by document type and sub type.