Lowering total cost of ownership with breakthrough magnetic torque transfer technology

Maintenance, unscheduled downtime, and energy costs are three of the highest budget items for any facility. Plants across North America are significantly reducing these costs through the use of magnetic torque transfer technology. This paper provides an overview of magnetic torque transfer technology and examines the savings potential that can be achieved with existing equipment. Magnetic torque transfer technology transmits torque from the motor to the load through an air gap. It works on the principle of magnetic induction and torque is generated as a function of slip between the input and output members. A magnetic coupling consists of two separate components that have no physical contact. Precision machined aluminum rotors containing high energy neodymium-iron-boron permanent magnets are mounted on the load shaft, and a conductor consisting of a steel housing with copper disks is mounted on the motor shaft. The coupling´s ability to transmit torque is created by the relative motion between the copper conductor and the magnets. This motion creates a magnetic field in the copper that interacts with the permanent magnets, thus transmitting torque though the air gap between the components. The motor is completely isolated from the load, which eliminates vibration between the units. The resulting decrease in vibration increases equipment life and reduces maintenance costs for such items as bearings, mechanical seals, couplings, etc. Further, isolation of motor and load eliminates the need for time consuming alignments. Unscheduled down time is reduced due to increased equipment reliability. An adjustable speed control device can be obtained using this same technology. Varying the width of the air gap changes the coupling force between the motor and load, producing an infinitely variable and controlled output speed. In industrial fluid or air handling systems, up to 67% energy savings have been realized by slowing the speed of the pump or fan rather than using control valves or dampers to achieve the desired flow. The unrestricted flow saves energy by reducing the load on the motor. The same maintenance and reliability benefits described in the magnetic coupling are also associated with the magnetic adjustable speed drive. Users throughout industry can maximiz- e existing asset value by increasing equipment reliability and up time, reducing maintenance costs, and lowering energy consumption. Magnetic torque transfer technology is providing these benefits to many plants today, for new construction and retrofit applications. Overall, thousands of systems (up to 3,000 HP at 1800 RPM) are currently utilizing this technology.