Issue Spring 13
Now, instead of an unyielding movement of products at the same speed past assembly stations, MagneMotion’s systems can provide more independent travel. It’s the difference between a 20-car train being pulled by an engine versus each car of the train being able to travel independently in either direction under its own power.
With linear synchronous motors (LSMs), products on vehicles with a passive permanent magnet array (secondary) interact with current driven through copper windings in a stator (primary) to create an electromagnetic field. The vehicle is then propelled by the electromagnetic field. The physical gap between the magnet array and the stator is a few millimeters. The speed of the movement is regulated by the amount of current applied to the copper windings, and the direction of travel is determined by the direction of electrical commutation.
MagneMotion has refined a technology originally developed for mass transportation systems with the latest software and hardware and adapted it to the task of moving products through a manufacturing plant for assembly. The versatility, speed and density of that vehicle movement can reduce energy and real estate costs and speed production by running more products on the line in the same or less space than a previous line occupied. Because it propels the payloads using electromagnetic forces rather than through friction and physical contact, the system can operate through the stainless steel walls of an isolator or glovebox and handle hazardous or nuclear materials.
The videos on MagneMotion’s websites show the versatility of movement possible with the company’s two industrial automation product lines, the MagneMover LITE (MM LITE) – which is designed for systems weighing 1 kilogram or less (2 kilograms using the MM LITE tandem puck) – and the QuickStick LSM, in which product line there are two different motors. The QuickStick 100 can handle loads from 2 to 100 kilograms and the QuickStick HT (for high thrust) can handle payloads up to 1,000 kilograms or more.
Electrical current is applied only when a vehicle is being commanded to move or hold a position, not across the entire vehicle track, thereby saving energy. This is unlike a belt or chain conveyor – which might energize and move a 50-foot conveyor section to transport a single product a few inches – or worse yet, run constantly and hold products back with mechanical stops. A proprietary control system uses patented position-sensing technology so the system always knows where every vehicle is located.
“Not only can we have an unlimited length of guideway with merges and diverges and curves, but we also are able to have many vehicles along that fixed guideway and know where they are at all times,” MagneMotion President and CEO Todd Webber declares. Each vehicle is moving under its own commanded profile and travels independently of other vehicles in the system, he says.
“Ours is really what we call a long stator linear motor transport system,” Webber explains. “MagneMotion’s systems can replace traditional conveyors, monorails, automatically guided vehicles or walking beams used in assembly and material handling. They also can be integrated with existing conveyor systems.
“It’s a frictionless drive system, which requires less maintenance than traditional systems,” Webber points out. “There are no belts or chains to wear. LSM technology offers greater control, greater throughput and more reliability. It all adds up to improved performance.”
Mandate to Innovate
The privately held MagneMotion was founded in 1996 by a group of engineers from Massachusetts Institute of Technology. “What we’re doing today wasn’t even possible when we first started out,” Webber maintains.
Advances in microprocessor speed, permanent magnet technology and the lowered cost of electronic components due to the auto industry’s greater use of them have combined to make MagneMotion’s current technology feasible and affordable.
“Our customers are constantly being challenged to make more for less,” Webber points out. “Our best customers are typically those that have a corporate mandate to innovate and improve processes, throughput and quality in the manufacturing process.”
Among the companies using MagneMotion systems are leaders in the medical device manufacturing, pharmaceutical, automotive, mining, consumer goods, solar panel, semi-conductor and packaging industries.
Cost is always a consideration when comparing manufacturing systems, and frequently an educational process is required for customers to understand all the possibilities of the company’s new approach. “If you make a one-to-one comparison between conveyor and linear synchronous motor technology, the upfront investment may be higher,” Webber states.
“However, if you look at the total cost of ownership and benefits – customers realize a significant reduction in third-party hardware and software with our systems while increasing throughput – we typically come out ahead of the competition,” he adds. “Customers who take a longer view and quantify the benefits of greater throughput, reliability, and maintainability quickly realize the advantages of our LSM transport systems.”