New production method makes electric motors half as expensive and twice as good

As a result of an entirely new way of making magnetic components in electric motors, the aggregate production cost for such motors is expected to be cut in half and the output of the motor to be nearly doubled. The method is the result of fifteen years of collaboration between researchers from the fields of electrical power systems and industrial production at the Lund University Faculty of Engineering in Sweden.

A key component in all of these motors is the magnetically conductive material, usually made up of bundled laminated thin plates with coils wound around them. This type of motor construction contains many small parts and takes a long time to manufacture.

“Electric motors have largely been made in the same way since the 1850s. Only in the last 10-15 years have alternative production methods been studied,” says Mats Alküla, professor of electrical power systems at the Engineering Faculty.

Together with his research colleagues Tord Cedell and Mats Andersson, Mats Alküla has found that an alloy of iron powder and a certain sort of plastic functions well in motor applications, among others, attaining good energy efficiency. By molding melted plastic and iron particles, which make the part weakly magnetic, in various forms, full freedom of form can be achieved. Besides higher quality and greater freedom of form, this method reduces the number of production steps from about 60 to only a few. The development of the material itself started in the late 1980s at the Section for Industrial Production, within the framework of the so-called materials technology consortia, funded partly by what is now Vinnova (Research and Innovation for Sustainable Growth).

“The technique is not suitable for high-performance motors, such as servo motors. But for fans, pumps, household appliances, and cars it’s a perfect fit,” explains Mats Alküla.

This research is funded with a total of SEK 12 million over five years from Vinnova, the Foundation for Strategic Research (SSF), and Industri Kapital. A patent is pending, to be issued in late October. What will happen to the patented solution after that­-whether a new company will be formed or the technology licensed out­-has not yet been decided by the researchers at CEMEC­Center for Electro-Magnetic Energy Conversion.

“The technology can pave the way for new possibilities, such as facilitating the conversion of cars to electric hybrid power. It’s worth mentioning in this connection that all methods that lead to simpler and cheaper production indirectly help curb carbon dioxide emissions,” adds Mats Alküla.

A prototype of the technology will be on display at the Lund University Faculty of Engineering booth at the Technology Fair in Älvsjö, Stockholm, Sweden, October 16-19.