Effects of Ultrasonic Oscillation on Shrink-Fitted Assembly

Shrink-fitting is widely recognized as the primary method for assembling interference fits. However, the use of the shrink-fitting technique in forming linkages between parts is often constrained by the requirement for high temperatures and the inevitable occurrence of surface damage. Consequently, an analysis of the integration of high-frequency stimulation, also known as ultrasonic oscillation, has been undertaken to develop a novel assembly procedure aiming at reducing the issues associated with shrink-fitted joints. The oscillation was conducted with generating power ranging from 500 to 1500 W and processing time from 10 to 70 seconds. The ultrasonic oscillated shrink-fitting procedure exhibits significant advantages, reduces surface damage while concurrently enhancing the axial holding load limit of the joint. This approach opens the door to the integration of new assembly techniques in small mechanisms, where straightforward joints are of paramount importance.