Abstract:
In the process of internal meshing power gear honing, elastic-plastic deformation occurs near the contact area between the workpiece gear and the honing wheel. This deformation is the superposition of various factors, and residual stress is generated on the workpiece surface after processing. The generated residual stress significantly affects the gear’s performance, fatigue strength, dimensional stability, and wear resistance, and it is closely related to stress corrosion cracking. To grasp the influence rule of process parameters on residual stress, this paper conducts in-depth research.
1. Introduction
1.1 Background and Research Significance
1.1.1 Source of the Topic
This topic originates from the National Natural Science Foundation of China project “Research on the Mechanism of NC Internal Gear Honing with Power Honing Wheel” (Project Number: 51575154) and the National Science and Technology Major Project “Y4830CNC NC Internal Gear Honing Machine with Power Honing Wheel” (Project Number: 2013ZX04002051), jointly undertaken by the CIMS Research Institute of Hefei University of Technology and Nanjing Erge Gear Machine Tool Co., Ltd.
1.1.2 Research Background, Purpose, and Significance
In recent years, with the efforts of researchers, free-cutting honing has gradually developed towards power honing, possessing the ability to correct gear tooth profile errors. Therefore, the research and development of internal meshing power gear honing machines and their processing technologies are crucial for improving China’s gear manufacturing level. Despite significant progress in honing technology research, there is still a considerable gap compared to international levels, especially in studies on residual stress on the surface of workpieces after honing.
1.2 Research Progress in Gear Honing and Residual Stress
Since the 1950s, researchers from various countries have studied residual stress and achieved significant results. The formation of residual stress on the workpiece surface during honing is a difficult problem, influenced by numerous factors. During the honing process, due to pressure, the workpiece gear undergoes intense plastic deformation, leading to significant residual stress on the tooth surface after honing.
Table 1: Research Progress in Residual Stress Measurement
| Researcher | Method | Application | Advantages | Limitations |
|---|---|---|---|---|
| Feng Baofu | Finite Element Analysis | High-speed grinding and high-efficiency deep grinding | Provides insights into stress distribution | Mainly focused on simple models |
| Others | Experimental | Various gears and surfaces | Direct measurement | Low precision, lack of practical experience |
1.3 Calculation Methods of Residual Stress
Currently, the commonly used methods for analyzing residual stress on honed surfaces include mathematical modeling, experimental research, and finite element modeling. Among them, the finite element method is the most widely adopted due to its accuracy and versatility.
1.4 Research Approach
This paper mainly follows these research steps:
- Derive the mathematical equation of the honing wheel tooth surface based on the principles of gear spatial meshing and spatial transmission of crossed-axis helical gears. Parameterize and model the tooth surface of the internal gear honing wheel in MATLAB.
- Study the mechanism of residual stress generation in honing and analyze the factors affecting honing residual stress.
- Use finite element dynamic simulation to analyze the influence of different radial forces, relative honing speeds, and shaft angles on the residual stress on the workpiece gear surface. Verify the simulation model’s validity through experiments.
- Analyze the influence of abrasive particle speed on honing residual stress under microscopic simulation.
2. Modeling of Internal Gear Honing Wheel
2.1 Principle of Internal Meshing Gear Honing
Internal meshing gear honing involves the process where the honing wheel tooth surface and the workpiece tooth surface press and cut each other under pressure, generating relative motion for honing processing.
2.2 Derivation of the Tooth Surface Equation of the Internal Gear Honing Wheel
Based on the principles of gear spatial meshing and spatial transmission of crossed-axis helical gears, the mathematical equation of the honing wheel tooth surface is derived.
3. Mechanism of Residual Stress Generation in Honing
During the honing process, plastic deformation occurs in the workpiece gear due to pressure, leading to the generation of residual stress. Additionally, the combined effects of honing force and heat, as well as friction between the workpiece and honing wheel, redistribute the initial stress on the tooth surface.
4. Finite Element Dynamic Simulation Analysis
In this study, a finite element dynamic simulation model is established to analyze the influence of different process parameters on residual stress.
4.1 Simulation Settings
The simulation settings include defining material properties, applying boundary conditions, and setting up the simulation environment.
Table 2: Simulation Settings
| Setting Item | Description |
|---|---|
| Material Properties | Gear material: steel; Honing wheel material: abrasive tool steel |
| Boundary Conditions | Fixed constraints on the base; Applied forces and speeds based on process parameters |
| Simulation Environment | ANSYS/LS-DYNA finite element analysis software |
4.2 Influence of Process Parameters on Residual Stress
4.2.1 Influence of Honing Speed
With the shaft angle fixed at 8.722° and the honing radial force at 150N, the workpiece rotation speeds were varied. The simulation results show that as the workpiece rotation speed increases, the honing residual stress values at different positions decrease, with varying degrees of decline.
4.2.2 Influence of Honing Radial Force
The simulation results show that as the honing radial force increases, the residual stress on the workpiece surface also increases.
4.2.3 Influence of Shaft Angle
As the shaft angle increases, the honing force decreases, and the honing speed increases, both leading to a reduction in honing residual stress.
5. Experimental Verification
To verify the simulation results, experimental measurements of residual stress on the surface of the honed workpiece were conducted using an X-ray diffractometer.
Table 3: Comparison of Simulation and Experimental Results
| Unit Number | Simulated Residual Stress (MPa) | Measured Residual Stress (MPa) | Error (%) |
|---|---|---|---|
| 56621 | -550 | -625 | 13.6 |
| 56326 | -605 | -684 | 13.1 |
| 56606 | -1200 | -1150 | 4.2 |
| 56926 | -950 | -1074 | 13.1 |
| 56586 | -362 | -367 | 1.4 |
| 55286 | -510 | -572 | 12.2 |
6. Microscopic Analysis of Abrasive Particle Speed
The microscopic simulation results show that as the honing speed of the abrasive particles increases, the residual compressive stress on the tooth surface of the workpiece decreases and tends to flatten out.
7. Conclusion
This paper studies the internal meshing power gear honing process, its mechanism, and the causes and influencing factors of residual stress on the surface of honed workpieces. A finite element simulation model is established to analyze the influence of honing radial force, relative honing speed, and shaft angle on residual stress. Experimental verification confirms the effectiveness of the simulation model.
The main findings are summarized as follows:
- A mathematical model of the internal gear honing wheel tooth surface is derived and parameterized in MATLAB.
- The mechanism of residual stress generation in honing is studied, and the influencing factors are analyzed.
- Finite element dynamic simulation is used to analyze the influence of various process parameters on residual stress.
- Experimental verification confirms the accuracy of the simulation results.