Shrink Fitting Cast Iron Rocker Arm Assemblies

A client contacted THE LAB at Ambrell looking to use induction to prepare cast iron assemblies for shrink fit assembly. THE LAB determined that an Ambrell EASYHEAT^TM 5.0 kW, 150-400 kHz induction heating system with a four-turn helical coil would be optimal for this induction shrink fitting application. 

The four-turn helical coil was designed to concentrate the field towards the center of the assembly where the thermal mass was greatest. Across the heated ring, the coil presented a lighter field. The frequency was set to 150 kHz for this application. After heating, a pin was placed within the ring and the assembly was water quenched. The heat time varied from part to part but was less than 20 seconds, which met the client's requirements. 

For this application, induction heating offered several advantages. It delivered rapid heating with even heat distribution. The coil design presented by THE LAB at Ambrell enabled parts of different geometries to be heated with the same coil. Additionally, this induction heating system and coil is suitable for an automated manufacturing process. Finally, unlike a flame, induction is a clean and comparatively safe heating option.

THE LAB at Ambrell has a significant amount of experience with induction shrink fitting applications like this one. Visit our induction shrink fitting page to learn about other shrink fitting applications assessed by THE LAB. 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.