# Dynamic Induction Heating Temperature Field Analysis of Spiral Bevel Gears
## 5 Conclusions  
According to the characteristics of tooth surface area division, dynamic induction heating of gears was carried out, and the research results show that the research objectives of a uniform temperature field and high heating efficiency could be achieved. By comparing the simulation analysis results of the transverse and longitudinal coils through the dynamic induction heating of spiral bevel gears, the longitudinal coil had a more uniform temperature field distribution on the tooth surface after heating than the transverse coil, and the longitudinal coil was determined as the heating coil. Furthermore, the accuracy of the simulation results was verified by designing a longitudinal coil heating experiment. The conclusions are as follows. 1. The heating efficiency of transverse and longitudinal coils and temperature field distribution of the spiral bevel gear tooth surface at different current frequencies and intensities were investigated. The results show that the surface temperature of the spiral bevel gears heated by the longitudinal coil was more uniformly distributed in the axial and circumferential directions. The temperature fluctuations and temperature differences on the gear surface were smaller, and the temperature differences between the root and the top of the tooth in the shot peening area were also smaller. Therefore, a longitudinal coil was used as the heating coil for the spiral bevel gear. 2. A spiral bevel gear induction heating test bench was built to conduct the dynamic induction heating experiments. The temperature variation of the spiral bevel gear tooth surface was recorded using a thermal imaging instrument. The experimental results were compared and analyzed using the simulated temperature data. The results show that the average temperature changes of tooth root and tooth top in the experimental measurement were 5.4 \({}^{\circ}\)C/s and 6.1 \({}^{\circ}\)C/s, respectively. The corresponding temperature changes in the numerical simulation were 5.23 \({}^{\circ}\)C/s and 4.97 \({}^{\circ}\)C/s. The tooth surface temperature in the experiment and the temperature fluctuation were larger than those in the numerical simulation. This is because the airflow rate and air temperature influenced the tooth surface temperature in the experiment. Overall, the tooth surface temperature distribution in the experiment was consistent with the simulation results. Therefore, according to the research results, the use of longitudinal coils for dynamic heating in the shot peening process can ensure uniform distribution of the tooth surface temperature field, and promote the strengthening effect of the shot peening on the gear. Figure 20: Temperature difference between points A and B. **Author Contributions:** Y.Z. : Conceptualization; formal analysis; methodology; investigation; writing. H.Z. : data curation; investigation; resources; formal analysis; writing. Y.Y. : funding acquisition; investigation; methodology; validation. P.Z. : data curation; investigation. All authors have read and agreed to the published version of the manuscript. **Funding:** This research is supported by National Natural Science Foundation of China (Grant No. 52075552). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The author declared that our data and material are available. **Conflicts of Interest:** The authors declare that they have no conflict of interest in this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted. **Nomenclature**