| WANG Ben,LI Zhanye,ZHAO Zhe,SONG Chang,JI Caihang,LI Xinyang.Friction Reduction Characteristics of Ultrasound-assisted Dismantling of Threaded Pairs[J],53(23):169-179 |
| Friction Reduction Characteristics of Ultrasound-assisted Dismantling of Threaded Pairs |
| Received:December 14, 2023 Revised:April 01, 2024 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2024.23.015 |
| KeyWord:ultrasonic vibration modal coupling longitudinal torsional composite threaded pair friction reduction rate |
| Author | Institution |
| WANG Ben |
School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang , China |
| LI Zhanye |
School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang , China |
| ZHAO Zhe |
AECC Shenyang Engine Research Institute, Shenyang , China |
| SONG Chang |
School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang , China |
| JI Caihang |
School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang , China |
| LI Xinyang |
School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang , China |
|
| Hits: |
| Download times: |
| Abstract: |
| In the exploration of disassembling threaded pairs, researchers are actively developing tools with a focus on minimizing removal torque, often overlooking the subsequent damage to the threaded surface post-disassembly. This oversight can significantly diminish the utility in contexts demanding high precision for secondary assembly. The incorporation of ultrasound, known for its friction-reducing and material-softening capabilities, is being examined for its role in threaded pair disassembly. The work aims to elucidate the impact of varying ultrasonic parameters and initial tightening torque on both the dismantling torque and the threaded surface morphology. Since the disassembly torque magnitude was intricately linked to the friction encountered on the contact surface of the threaded pair, a comprehensive theoretical analysis was carried out to explore the friction reduction trends of ultrasonically disassembled threaded pairs under various ultrasonic directions, amplitudes, and frequencies. To facilitate this exploration, an experimental apparatus, grounded in the principles of ultrasonic coupling, was employed for conducting the threaded pair dismantlement experiments and the disassembly torque output from the torque transducer under different ultrasonic parameters was recorded, which was compared with that of the normal disassembly torque to derive the friction reduction rate. Finally, the disassembled nut was dissected from the middle, and the surface morphology of the threads after normal disassembly and ultrasonic disassembly was observed by a super depth-of-field microscope. Current findings reveal that the friction reduction rates achieved through torsion, longitudinal, and longitudinal-torsion composite ultrasonic directions stand at 4.5%, 10.2%, and 11.9%, respectively. Microscopic analysis of post-disassembly exposes that nuts exhibit large flaking chips on their threaded surfaces. The application of ultrasound, however, morphs these chips into smaller flakes, effectively mitigating surface damage. Additionally, the study notes friction reduction rates associated with ultrasonic amplitudes of 0.1 μm, 0.3 μm, and 0.5 μm at 2.9%, 7.9%, and 11.9%, respectively. Notably, at a minimal amplitude of 0.1 μm, large flaking particles and minor scratches emerge on the surface. Conversely, elevating the amplitude to 0.5 μm marks a decrease in threaded surface damage. Moreover, ultrasonic frequencies of 20 kHz, 28 kHz, and 40 kHz correspond to friction reduction rates of 11.2%, 11.5%, and 11.9%, respectively. Observations indicate negligible ablation of threaded surfaces at 20 kHz, whereas at elevated frequencies, such as 28 kHz and 40 kHz, the incidence of black ablation from high-temperature friction becomes increasingly evident, directly leading to increased contact surface damage. The confluence of theoretical and experimental insights leads to several pivotal conclusions, namely that the longitudinal-torsional composite ultrasound emerges as the superior approach in reducing friction with minimal threaded surface damage. Augmenting the ultrasonic amplitude bolsters the friction reduction effect and curtails threaded surface damage. While ultrasonic frequency exhibits a marginal impact on friction reduction, higher frequencies precipitate enhanced surface ablation. Consequently, opting for low-frequency ultrasound remains preferable when the ultrasonic direction and amplitude are held constant. These empirical insights are poised to significantly inform the development and design of ultrasonic threaded pair dismantling devices. |
| Close |
|
|
|