Study on the Influence of Coil Cone Angle on the Temperature Uniformity of Spiral Bevel Gear Induction Heating

Abstract Due to the small size and complex structure of medium and small modulus spiral bevel gears, the current quenching technology struggles to control the temperature uniformity of their tooth shape, which impacts the surface hardening quality of the gear. In this article, a three-dimensional finite element model of induction heating is established by using the finite element method of multiphysical field coupling. It is found that when equidistant coil induction heating is applied to the gear, the temperature at the large end of the gear is significantly higher than that at the small end. Therefore, this article proposes a gap distribution method with unequal spacing between the coil and the workpiece by adjusting the coil cone angle. With the increase of the coil cone angle, the region with the highest magnetic field intensity shifts toward the small end, and the temperature uniformity is improved. When the coil cone angle reaches 70 deg, the overall temperature qualification rate increases by 23.16%, the average temperature in the tooth width direction stabilizes between 900 °C and 1000 °C, the maximum temperature difference decreases by 20.57%, and the temperature dispersion coefficient decreases by 0.0296. At this point, the uniformity of the tooth surface temperature is optimal.