Frequently Asked Questions
Between 15 and 30 years depending on the duty cycle and proper maintenance.
Applications currently benefiting from use of MagnaDrive’s technology include: pumps, fans, blowers, centrifuges, and bulk handling equipment. Industries served include: water and wastewater treatment, pulp and paper manufacturing, power generation, oil & gas processing, cement, mining, chemical & food processing, irrigation, maritime and HVAC systems. These installations are demonstrating significant energy savings and reduced system vibration.
In industry, significant energy savings can be realized by matching the speed of the load to variable fluid requirements. An example would be a pump that could change water volumes through control valve in the course of a production shift. The energy and financial penalty of running a pump, fan or blower faster than necessary to accomplish the work at hand is severe. Conversely, the savings available through matching the load speed to system requirements can be very high. MagnaDrive’s technology provides energy savings up to 70%.
Variable Frequency Drives are electronic devices that control the speed of the motor by controlling the frequency of the voltage supplied to the motor. The VFD converts three-phase 60 hertz AC voltage to AC voltage at a desired frequency. Controlling the frequency controls the motor speed, as the speed of an induction AC motor is proportional to the frequency of the voltage applied.
In a typical ASD application, the ASD is installed between a motor and the load the motor is driving, generally a pump, fan or blower. The drive consists of two independent components that have no physical contact. One component, a precision rotor assembly containing high-energy permanent magnets, is mounted on the load shaft. The second component, a copper conductor assembly, is connected to the motor shaft. Relative motion between the magnets and the copper creates a magnetic field that transmits torque from motor side to load side. In effect, the magnetic “pull” between the magnets on the load side of the drive and the copper on the motor side creates the coupling force; varying the width of the air gap changes the coupling force, so the amount of torque transmitted between the motor and load can be continuously adjusted. This allows precise and efficient speed control for optimum performance, including “cushioned starts.” The result is a much more efficient use of energy. Because there is no direct mechanical connection between the motor and load, the MagnaDrive ASD also eliminates the costly wear-and-tear of vibration. The MagnaDrive Coupling works on the same principle but with a fixed air gap, the output speed is constant.
Because there is no direct mechanical connection between the motor and the load, the motor can be started independently from the load. The load can then be slowly accelerated to operating speed. Reducing motor in-rush current at start-up prevents damaging heat build-up in the motor, as well as voltage sags and brownouts that create problems for other electronic equipment in a facility. In addition, utility demand charges are greatly reduced by reducing the motor in-rush current, and motors can be sized for optimal operating torque rather than higher starting torque.
By using the MagnaDrive ASD to control flow in a process instead of a control valve or damper, you save energy by slowing the load speed to maintain flow. This means the flow becomes unrestricted, unloading the motor and saving energy. Also, this technology has the ability to start the equipment while completely disconnected from the load, which means shorter duration of in-rush current to the motor at start up and reduced shock loading from hard starting the equipment.
The first MagnaDrive products were sold in 1999. Since then more than 10,000 MagnaDrive Magnetic Coupling’s and ASD’s have been installed.
Rare earth permanent magnets are key to MagnaDrive’s product performance. Permanent magnets are an important part of our everyday lives, serving as essential components in everything from electric motors, computers, production equipment and automobiles. Rare earth permanent magnets are made of a combination of Neodymium, Iron and Boron (NdFeB). This technology is the most recent addition to the family of high performance permanent magnets, and became commercially available in the 1980’s.
The MagnaDrive ASD competes with a wide variety of control valves, louvers, re-circulating valves, transmissions, fluid drives, VFD’s, mechanical belt devices, etc.
Rare earth magnets have the highest energy product of all permanent magnets, permitting the small size and high torque transmission capability of the MagnaDrive technology. NdFeB magnets will retain their magnetic performance properties for the life of the MagnaDrive product.
The simple and reliable MagnaDrive ASD is ideally suited to pump, fan and blower applications, providing the energy savings of speed control without the problems often associated with VFDs. In these installations, system complexity is reduced, and issues caused by vibration and misalignment are reduced. Motor systems can be resized for lower cost and more efficient operation. In addition, the MagnaDrive technology makes adjustable speed control available to markets previously resistant to using VFDs.
If the magnets are exposed to temperatures exceeding 350 Deg F, they demagnetize. We keep the temperatures within the magnet rotor well below this temperature.
In most cases, the MagnaDrive ASD benefits result in a substantial savings to the customer. However, depending on the application, MagnaDrive products may not represent the lowest initial cost. If initial cost is the only evaluation criteria when selecting a product, MagnaDrive appears too expensive. But, MagnaDrive is typically the better choice by a wide margin if the total cost of ownership is evaluated over the life of the system, taking into account the benefits and the cost of all drives and couplings and replacements required over the life of the system.
The half-life of the magnets is 2,000 years.
There are significant differences between old technology eddy current drives and new technology MagnaDrive ASDs. An eddy current drive is electromagnetic; it consumes electrical energy as it continuously energizes its electromagnets. MagnaDrive is mechanical, using rare earth magnets. The MagnaDrive is about 10-15% more efficient throughout its operating range and its disconnected technology results in vibration reduction.
The fact that the two components have no physical connection means that vibration will not transfer between shafts, so the time-consuming and costly laser alignment process typically needed for conventional coupling installation is no longer necessary.
On a centrifugal application with a varying torque load the magnet rotors do not get hot but the conductor does rise in temperature. The heat generated in the conductor is dissipated by convection as well as conduction.
Yes. The MagnaDrive ASD is a simple mechanical device – the product works the same regardless of the power supply voltage.
There are two bearings and four pivot assemblies in the MagnaDrive ASD that require periodic greasing. The grease fittings are easily accessible and can be serviced when the maintenance person greases the motor.
Any actuator that has a 90-degree stroke will work with the MagnaDrive ASD.
The ASD itself does not require direct application of electrical power. The multi-turn actuators typically sold with an ASD require 120/220vAC single-phase 50 or 60Hz; they also accept 4-20mA or 0- 5vDC for control signal.
Yes. When pumping water at 100 gallons per minute, the MagnaDrive ASD can hold its set point to 0.50 of a gallon.
Because there is no physical contact between shafts, parallel misalignment up to 0.2 inch is tolerated without creating vibration with less vibration there should be increased equipment life and less maintenance required. In conventional shaft connection technology, misalignment results in vibration, significantly reducing equipment life.
This depends on the size of the MagnaDrive product. The distance between shaft ends (DBSE) for ASDs ranges from 12 to 64 inches. The Coupling DBSE ranges from 4 to 10 inches.
Typically, when the MagnaDrive product is operating at full speed, it will slip around one to three percent depending on the application.
There are no electrical harmonics. Unlike a VFD that can cause serious vibration problems such as bearing failures and fluting due to electrical harmonics, the MagnaDrive ASD does not create any electronic frequencies.