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About MagnaDrive Drives Couplings News Links Home

MagnaDrive was featured on the cover of the Motion System Design(MSD) Magazine - April Edition. Attractive alternative to ASDs A new type of rotary drive based on magnetic force promises big energy savings (as well as lower maintenance costs) in adjustable speed applications. Developed by MagnaDrive Corp., Seattle, the speed- regulating device can reduce energy consumption by as much as 65% when used with medium-voltage (2,300 to 4,160- Vac) motors running at speeds to 3,600 rpm. The drives consist of two parts. One part, a copper plate, connects to the motor; the other part, a rigid assembly of Ne- Fe- B magnets, connects to the load. Relative motion between the parts creates a magnetic field that transmits torque. Changing torque is simply a matter of varying the width of the airgap between the parts. The smaller the gap, the more torque. By shrinking or expanding the gap, the drive can precisely control torque as well as speed, achieving even “soft” starts and overload protection. Another benefit associated with magnetic drives is reduced wear- and- tear on bearings and seals. Ordinary mechanical drives transmit, and even produce, vibrations. Magnetic drives, on the other hand, act as a filter, isolating vibrations (and bearing wear) on one side of the airgap or the other. In one application, at Ash Grove Cement Co. in Durkee, Ore., magnetic drives cut maintenance costs by over $10,000 a year. The problems stemmed from a 125- hp, 1,800- rpm motor running a belt- driven fan. Startups were particularly hard. Not only did they shake ductwork and support structures, they also caused voltage sags (brownouts) and heating in the bearings and sheaves. Using the same motor, but moving it in- line with the fan shaft, the magnetic drive cut vibration by a factor of ten. It also eliminated the sheaves and belts and most of the running noise. What’s more, because the motor starts up uncoupled from the fan then slowly engages, locked rotor current is no longer a concern nor are the previous problems associated with electronic noise. For more information on magnetic adjustables peed drives, visit Magna Drive’s website at www. magnadrive. com. Copyright © 2001 by Penton Media, Inc., Cleveland, Ohio 44114 FAQ | Contact Us | Home Copyright © 2008 MagnaDrive Corporation, All Rights Reserved.