Dual‐frequency induction heating for gear hardening: converter, resonant circuit, and FEM modelling

Abstract

In order to achieve required mechanical properties of hardened elements, such as gear wheels, dual-frequency induction heating may be used. Dual-frequency allows heating only the outline of the gear, due to mixed penetration depth of the subject frequencies. This method of hardening requires the process to be very short as heat may spread by means of conduction. This study presents a 3 kW prototype inverter and its control scheme is used to generate dual-frequency output current. The overall efficiency of the inverter is 96%. An analysis of the output resonant circuit is made to find the resonant frequencies. Finally, circuit and finite element method (FEM) simulations are coupled to analyse the effect of dual-frequency current on the magnetic field, current density, and energy density on the surface of a gear wheel.

Single Three-Phase Inverter for Dual-Frequency Induction Heating

“…Patents resulting from the work reported in this manuscript [25,26]. Author Contributions: Conceptualization, K.F.…”

“…Two inverter topologies are proposed. The following designations of 2T1C [25] and 3T [26] are adopted in this paper. The 2T1C topology shown in Figure 3 contains two transistor branches (2T) and one common capacitor branch (1C), which can be used to eliminate the DC component.…”

“…These 2T1C and 3T topologies combine the advantageous features of two-and one-inverter solutions, i.e., the ability to control individual components of the inductor current and independently adjust the load impedance minima (independent matching transformers), as well as simplicity. Both proposed topologies are protected by Polish patent claims [25,26]. A comparison of the basic properties of these and similar systems for dual-frequency IH covered by the patent claims is shown in Table 1.…”

Mobile Induction Heat Treatment of Large‐Sized Spur Gear—The Effect of Scanning Speed and Air Gap on the Uniformity of Hardened Depth and Mechanical Properties

“…[ 3 ] Tong et al improved the numerical model by introducing an additional plastic strain model for application in spur gear's asynchronous‐dual frequency induction hardening. [ 15 ] The insights of numerical simulation preparation in dual‐frequency induction heating along gear tooth profile were presented by Kierepka et al [ 16 ] More simulation works in dual‐frequency in achieving the uniformity of temperature distribution in bevel gear were can be studied in the recent works of Zhao et al [ 17 ] Wang et al showed exciting works in the scanning induction hardening simulation and the effect of scanning speed by incorporating commercial software. [ 18 ] Zhong et al showed an improved model by considering martensite transformation plasticity.…”

The Design of a System for the Induction Hardening of Steels Using Simulation Parameters

“…A higher efficiency for induction hardening could be achieved using a particular test setup, with an approach relying on efficiency maximization, leading to an efficiency of up to 91% [35]. An efficiency above 95% is reserved for low-temperature applications, where even 97% efficiency is achievable [36]. However, in induction hardening, only special systems like dual-frequency induction heating (efficiency of the inverter up to 96%) [37] can reach the goal.…”