Contact UsToll-free (877) 251-6520
Iowa State University  |
The Power of MaterialsGroschopp Inc. of Sioux Center, Iowa, engineers and manufactures customized, high-reliability fractional horsepower electric motors and gear motors for some of the world’s most demanding Original Equipment Manufacturers. On several occasions, the company has turned to IPRT Company Assistance to help it maintain its reputation for products of the highest quality. Springing into ActionOne project involved a critical spring in a small electric motor. The stainless steel spring was breaking during operation. Based on preliminary analysis, Loren Kamstra, an engineer at Groschopp, suspected that the cause was chlorine used in a lubricant by the spring supplier. He came to Paul Berge, a metallurgist in IPRT Company Assistance, to confirm the analysis and find a solution. Berge enlisted the assistance of Warren Straszheim of the Materials Analysis and Research Laboratory, part of the Materials Science and Engineering Department at Iowa State University. Staszheim’s analysis confirmed that the springs did indeed show signs of chloride residue. The team analyzed a number of other samples to see if Groschopp could do anything to reduce the chlorine since its supplier was unwilling to do so. The samples all showed signs of chlorine, so Berge worked with Kamstra to specify an alloy material more resistant to chloride cracking. Although the new alloy was more expensive, this solution ensured that the springs would not break. “For the spring investigation alone, we saved around $5,000 per reported breakage,” says Kamstra. He adds that Groschopp was impressed with how quickly IPRT was able to turn the project around. “Our customer was also very appreciative of all the work IPRT did. They’re in the automotive industry, so to impress them says a lot,” he adds. Getting into GearGroschopp also makes gearboxes to produce specific speeds or change the shaft direction of a motor. The company does extensive testing to ensure its gearboxes will operate reliably. It was during one of these tests that a failure arose in a shaft of a gearbox. Jim Feldhacker, a design engineer at Groschopp, thought the design was good, so he suspected a material problem and went to Berge for insight. The shaft was made from “free machining steel,” a common, widely used material. Berge thought this material might be the cause of the failures. While it meets specifications for hardness and other characteristics, it doesn’t always stand up in fatigue performance. “That’s a result of imperfections in free machining steel,” Berge says. The shaft was undergoing what Berge calls a “rotational reverse bending,” generating an extreme load that the free-machining steel couldn’t handle. Berge’s examination of the shaft’s fractured surfaces confirmed his theory. Berge worked with Feldhacker to devise a solution, specifying a different material and recommending having the entire shafts heat treated. “I was very impressed with Paul’s expertise,” says Feldhacker, “We have not had product returned for broken shafts, so we were able to eliminate the situation before it became a problem for our customers.” Sharing the KnowledgeBerge and Rick Lopez, another IPRT scientist, also visited the company to share general advice on materials selection and nondestructive evaluation technologies. “We learned a lot from the IPRT scientists, which has led us to change the material on a lot of the shafts we heat treat,” Kamstra says. Feldhacker adds, “We now know we have resources available for questions or testing we may need help with.” IPRT works for Iowa |
Quick LookScientists from IPRT Company Assistance helped Groschopp Inc., a Sioux Center manufacturer, on several occasions. IPRT's insight and advice on materials problems helped the company maintain its high product quality.
Groschopp manufactures electric motors used in applications such as electronic drivetrains made by world-class automotive suppliers. In one of Groschopp’s DC permanent magnet motor designs, a small spring is used to apply a force to a carbon brush, delivering power to the motor’s armature. In one application, the spring was breaking due to stress corrosion cracking. IPRT helped confirm the source of the breakage and recommended an alloy material to fix the problem and eliminate potential failures.
Broken shafts in a gearbox assembly made by Groschopp could result in failures of automated doors, golf ball washers, fluid pumps and many other applications. When the company discovered that the shaft was breaking during testing, it turned to IPRT for assistance, which helped determine the cause of the broken shaft and propose a solution. Groschopp, Inc.420 15th Street NE Contact Us
For more information on how IPRT can help your company solve its materials problems, please contact: Tom Lograsso
Institute for Physical |
Institute for Physical Research and Technology
Copyright © 2008, Iowa State University of Science and Technology. All rights reserved.