Application of Ultrasonic Friction Reduction Technology during the Bolt Tightening Process

Fasteners play a crucial role in the stability of mechanical systems. However, during the tightening process, the high friction characteristics of contact areas between the bearing surface and a threaded pair not only significantly hinder the effective conversion of torque into axial force, but also damage the microscopic state of contact surfaces, affecting tightening stability. This study directed adoption ultrasonic friction reduction technology, aiming to mitigate adverse effects caused by friction during the tightening process. The research results show that ultrasonic vibration exerts a significant optimization effect on the tightening process: it can effectively reduce frictional losses during tightening as well as microscopically alleviate friction-induced damage to contact surfaces, unlike conventional lubrication methods, the ultrasonic friction-reduction effect is generated dynamically during tightening and ceases when the ultrasonic excitation is removed. This enables improved torque conversion without introducing an additional lubricating medium into the contact interface. This enables better torque conversion and enhances the stability of bolt tightening.