Shrink Fitting an Automotive Aluminum Motor Housing

A client reached out to THE LAB at Ambrell because they needed to heat an aluminum motor housing to 464 ºF (240 ºC) for a shrink fitting application. The system will be used within an automated line. THE LAB determined that an Ambrell EKOHEAT^® 45 kW, 50-150 kHz induction heating system with a single position nine-turn internal bore coil would be optimal for this shrink fitting application.

Visit our induction shrink fitting page to see additional shrink fitting applications assessed by THE LAB.

During testing, the part was painted with temperature indicating paint that would melt to a clear color once it achieved the targeted temperature. The temperature indicating paint was also used to show balanced heating. With 0.125” (3.2 mm) radial clearance, the EKOHEAT met the temperature requirements within the targeted seven second time period. The key in the application was to maintain a modest radial clearance as an increase would require more power, increased water flow, and a more complicated coil.

For this client, speed and getting a repeatable, reliable result led them to choose induction heating, along with its ability to be integrated into an automated line. When compared to other heating methods for shrink fitting, induction's benefits include its speed along with its localized, repeatable, non-contact heating. Induction is also energy efficient, as it heats the part, not the atmosphere around the part. Finally, it's easily integrated into production lines due to its modest size, especially when you consider that the workhead can be placed away from the system itself.

THE LAB at Ambrell has a considerable amount of experience with induction shrink fitting applications.  And, to learn more about free application testing, visit our page with more information about THE LAB or contact us today to get the process started. Keep in mind, we now offer Virtual Lab Service so you can observe testing live from the comfort of your office.