In many industrial applications, manufacturers can be choosy about the motors they use to power their products. When the application needs to be mobile, however, or powered from battery or solar sources, it becomes critical to find the right trade-off between power, size, and weight. Equipment manufacturers today are searching for solutions that provide higher horsepower in a more cost-effective design than traditional NEMA 56 frame motors.
For customers that have specialized needs for 12- and 24-volt motors with more power capabilities, Minnesota Electric Technology (MET) recently introduced a class of permanent magnet DC motors intended for mobile, battery-powered (or solar-powered) equipment that requires variable speed and the ability to reverse the direction of rotation. According to MET CEO David Kvamme, the new high-torque-density family of products bridges a gap between the company's 3.2-inch diameter and 6-inch diameter motor offerings by covering output requirements from 1/3 horsepower to 2 HP in a 3.6-inch diameter motor.
"As batteries become smaller and grow in capacity -- thanks to the demand for better electric vehicles -- customers are developing more battery-powered applications," Kvamme told Design News. He said that most motors that can carry the current needed to produce these higher horsepower requirements have three major disadvantages: they're large, heavy, and expensive. "We developed our new motor line to fill this need with smaller, lighter, and less expensive motors."
The compact size of the new series allows MET to use components that are smaller and less costly than comparable motors while still using its present production line machines. The lighter weight of the motors leads not only to a broader set of applications, but lower packing and shipping costs, as well as energy savings by end users.
"Energy efficiency will, from now to forever, be on the forefront of most projects," noted Kvamme. "Society is becoming more demanding of energy-efficient solutions, and OEMs are following suit with systems that meet these demands."
Thanks to the launch of the new product line, much of MET's growth is likely to be in the mobile markets, including motorized dollies and lifters, floor-cleaning equipment, forklifts, hydraulic pumps, and water pumps. These OEM customers are looking for customizable solutions, and Kvamme said the company can meet those needs by using proprietary software to determine the build required to meet the customer's motor requirements.
The size and shape of the motor brushes and the grade of the material are all closely matched to each customer's application to offer the longest brush life possible, according to the company. MET works with customers to develop a prototype motor to test in the end products, and strives to remain flexible enough to customize electrical, mounting, and interface requirements while identifying cost drivers to find the right balance for equipment manufacturers.
One feature that sets the company apart, it said, is the "Made in America" approach. For many of the company's customers, US-made products mean not only better products, but better service and more cooperation in customization.
"Historically, US manufacturers could access low-cost Asian motors if they were willing to prioritize cost over quality," said Kvamme. "US manufacturers, however, are beginning to realize the damaging consequences that offshore purchases are having on our country's economy. Chinese factories do not meet the same air pollution limits that the US factories do, which allows them to make cheaper products."
Tracey Schelmetic graduated from Fairfield University in Fairfield, Conn. and began her long career as a technology and science writer and editor at Appleton & Lange, the now-defunct medical publishing arm of Simon & Schuster. Later, as the editorial director of telecom trade journal Customer Interaction Solutions (today Customer magazine) she became a well-recognized voice in the contact center industry. Today, she is a freelance writer specializing in manufacturing and technology, telecommunications, and enterprise software.