Shrink-fitting train wheels with induction heating

Staying on track

Alessandro Mariani of EFD Induction Italy explains how induction shrink-fitting keeps the trains running.

All of us remember as children gazing in wonder as trains thundered by. But what very few of us then realized—few still do—is that trains need to regularly change their metal wheels.


It sounds like hard work, but EFD Induction equipment makes the procedure clean and easy. A standard EFD Induction converter, the Sinac 150 SM, is fitted with a specially designed coil that heats wheel rings for quick disassembly. The same converter and coil is also used to shrink-fit new rings. Of course, train wheels come in different sizes. But the EFD Induction coil can be easily adjusted to fit different diameters. This is made possible by moving the segments that make up the coil. A centering device ensures that the wheel ring is securely and accurately held in the center of the induction coil. Software built into the Minac lets the operator pre-set the desired ramp-up times, power delivery and dwell times. This ensures that the correct surface temperature and heat pattern for the rings are achieved. When it comes to trains, EFD Induction equipment is used for more than removing and assembling wheels. Another standard EFD Induction converter, the Minac 18, is perfect for disassembling and shrink-fitting bearing and lock rings. There are, of course, plenty of other applications in train construction and maintenance where EFD Induction equipment can be used. To find out more about them just contact your nearest EFD Induction representative.