Abstract
The internal gearing power honing process model for high-speed gears and its surface integrity characterization and evaluation. By analyzing the kinematics and material removal mechanism of the internal gearing power honing process, a numerical model is established to simulate the honing process. Experiments are conducted to verify the accuracy of the model and evaluate the surface integrity of the high-speed gears. The results show that the internal gearing power honing process can significantly improve the surface roughness, hardness, and hardness uniformity of the high-speed gears.
1. Introduction
High-speed gears, with meshing line speeds exceeding 25 m/s or rotational speeds greater than 3600 r/min, serve as crucial components in high-speed transmission systems. Their performance directly impacts the reliability and stability of these systems. Surface integrity, which encompasses geometric and physicochemical properties such as surface texture, roughness, hardness, residual stress, and metallurgical structure, is a comprehensive indicator of a component’s service performance, lifespan, and reliability.
Table 1. Classification of High-speed Gear Tooth Profiles
| Classification | Description |
|---|---|
| Involute tooth profile | The most common tooth profile in gears, characterized by a smooth and continuous curve. |
| Arc tooth profile | Offers better contact and lubrication properties, reducing noise and wear. |
2. Literature Review
Research on gear honing and surface integrity has been ongoing for decades. Early studies by Field and Kahles introduced the concept of surface integrity, emphasizing its importance in evaluating machined and ground high-strength steels. Subsequent research has focused on optimizing honing processes and characterizing surface integrity parameters.
3. Mechanism of Internal Gearing Power Honing Process
3.1 Kinematics Analysis
The internal gearing power honing process can be equated to the meshing motion of a pair of internal intersecting-axis gear pairs. By analyzing the contact motion relationship between the honing wheel and the workpiece gear, the meshing equation is established to explain the envelope generation process of the honing wheel tooth surface and the workpiece tooth surface.
3.2 Material Removal Mechanism
The material removal characteristics of the internal gearing power honing process are studied by analyzing the abrasive particle characteristics on the honing wheel surface and the force state of the workpiece gear. The results reveal the material removal mechanism of the process.
4. Numerical Modeling of Internal Gearing Power Honing Process
4.1 Numerical Modeling of Surface Texture
The surface texture of high-speed gears is numerically modeled by considering the abrasive cutting marks left by the honing wheel. The tooth profile of the workpiece blank is discretized, and the abrasive cutting marks on the tooth surface are calculated to digitize the surface texture.
Table 2. Parameters for Numerical Modeling
| Parameter | Description | Value |
|---|---|---|
| γ | Angle between the honing wheel and the workpiece axis | Varies |
| Z_h | Number of teeth on the honing wheel | 11 |
| n_h | Rotational speed of the honing wheel spindle | 3860 rpm |
4.2 Numerical Modeling of Surface Roughness
The maximum groove depth oriented perpendicular to the tooth surface texture is calculated to numerically model the surface roughness of the high-speed gears processed by internal gearing power honing. This model enables the prediction of surface roughness based on process parameters.
5. Experimental Verification and Surface Integrity Characterization
5.1 Experimental Design
Experiments are conducted to verify the accuracy of the numerical model and evaluate the surface integrity of high-speed gears. A high-speed gear from a new energy vehicle transmission box is selected as the test object.
Table 3. Parameters of Gear Blank for Experiments
| Sequential Number | Parameter Name | Value |
|---|---|---|
| 1 | Material of gear blank | Steel |
| 2 | Module | 3 |
| 3 | Number of teeth | 21 |
| 4 | Helix angle | 20° |
| 5 | Pressure angle | 20° |
5.2 Measurement and Analysis of Surface Texture and Roughness
The surface texture and roughness of the high-speed gears are measured using a super depth of field 3D microscopic system and a confocal laser scanning microscope. The measurement results are compared with the numerical simulation results to verify the accuracy of the model.
Table 4. Surface Roughness Measurement and Model Calculation Results
| Measurement Area No. | Measured R_a (μm) | Calculated R_a (μm) – Spherical Abrasive | Calculated R_a (μm) – Conical Abrasive | Relative Error (%) – Spherical Abrasive | Relative Error (%) – Conical Abrasive |
|---|---|---|---|---|---|
| 1-1 | 0.334 | 0.325 | 0.323 | -2.69 | -3.29 |
| 1-2 | 0.363 | 0.357 | 0.440 | -1.65 | 21.21 |
| 1-3 | 0.426 | 0.408 | 0.489 | -4.23 | 14.79 |
| 1-4 | 0.419 | 0.414 | 0.495 | -1.19 | 18.14 |
| 1-5 | 0.411 | 0.420 | 0.501 | 2.19 | 21.90 |
| 1-6 | 0.462 | 0.449 | 0.528 | -2.81 | – |
5.3 Analysis of Surface Hardness
The hardness of the high-speed gears before and after internal gearing power honing is measured using a hardness tester. The results show that the internal gearing power honing process can produce a higher surface hardness and a smaller hardness gradient compared to the grinding process.
6. Conclusion and Future Work
This thesis presents a comprehensive study on the internal gearing power honing process model for high-speed gears and its surface integrity characterization and evaluation. By establishing a numerical model and conducting experiments, the accuracy of the model is verified, and the influence of process parameters on surface texture, roughness, and hardness is analyzed. The results demonstrate the effectiveness of the internal gearing power honing process in improving the surface integrity of high-speed gears.
However, there are still areas for improvement in future work. The abrasive particle morphology on the honing wheel surface can be parameterized to further enhance the accuracy of the model. Additionally, intelligent optimization methods can be proposed to optimize the honing process parameters. Finally, research on the honing force during the internal gearing power honing process and its impact on surface quality can be conducted to reveal the underlying mechanisms.