Abstract: Gear manufacturing constitutes the largest industry among mechanical basic parts. With the rapid development of equipment manufacturing in China, the requirements for gear processing have become increasingly stringent. The continuous application of advanced CNC equipment has significantly transformed cutting processes and technologies. Gear shaving, as a core part of the gear finishing process, is now widely employed in various gear finishing applications, ranging from small gears used in automobiles, reducers, and agricultural machinery to large reduction gears used in marine turbines. This thesis focuses on metal cutting fluids, with the gear shaving machine as the research object, proposing a transition from oil-based cutting fluids to water-based cutting fluids to achieve greener processing and reduce environmental pollution.
1. Introduction
1.1 Background and Significance of the Research
The manufacturing industry has witnessed tremendous advancements, particularly in gear processing technology. Gear shaving, first applied in the United States in 1926, offers advantages such as high efficiency, low cost, and no burns or cracks on the tooth surface compared to gear grinding. As a result, gear shaving is extensively used in batch production for gears in automobiles, tractors, and machine tools.
1.2 Characteristics of Gear Shaving
Gear shaving utilizes a shaving cutter on a CNC shaving machine to finish the gear tooth shape, tooth direction, and tooth surface, specifically for processing unquenched cylindrical gears. It features low transmission noise and reduced or eliminated heat treatment deformation.
1.3 Overview of Gear Shaving Cutting Fluids
1.3.1 Oil-Based Cutting Fluids
Traditional oil-based cutting fluids have poor cooling effects, especially during high-speed cutting. The poor heat transfer can lead to excessively high temperatures in the cutting zone, producing phenomena such as smoke and fire, and affecting workpiece accuracy due to thermal deformation.
1.3.2 Water-Based Cutting Fluids
Compared to oil-based cutting fluids, water-based cutting fluids exhibit excellent heat resistance and reduced consumption of non-renewable resources like oil, offering broader application prospects for research and development.
1.4 Research Status and Development Trends of Environmental Protection Cutting Fluids
1.4.1 Research Status of Environmental Protection Cutting Fluids
Water-based cutting fluids emerged in the 1940s and have rapidly developed due to their superior cooling performance and lower cost compared to oil-based cutting fluids. In the United States and European developed countries, water-based cutting fluids have become the most important metal cutting fluids, with microemulsions and fully synthetic cutting fluids gaining widespread application.
1.4.2 Development Trends of Environmental Protection Cutting Fluids
With increasing focus on environmental issues, resource utilization, and human health, green environmental protection has become a key research area in cutting fluids. Trends include:
- Development and application of universal cutting fluids.
- Green use and disposal of cutting fluids.
- Transition from oil-based to water-based cutting fluids.
2. Theoretical Basis and Experimental Design
This thesis analyzes and summarizes the principles and processes of gear shaving, establishing an optimized route for green gear shaving processes. It focuses on the green selection of cutting fluids and the optimization of process parameters.
3. Experiments on the Processing Performance of Gear Shaving Cutting Fluids
3.1 Overall Design Scheme
The experiment compared different types of water-based and oil-based cutting fluids, assessing their cooling and lubrication performance, workpiece processing quality, tool life, and cost control.
3.2 Experimental Conditions
The experiment was conducted on a YDA4232CNC CNC gear shaving machine at Chongqing Machine Tool Group Shenjian Automotive Transmission Component Co., Ltd.
3.3 Comparative Analysis of Experimental Results
3.3.1 Workpiece Quality Analysis
The surface roughness and dimensional accuracy of the workpieces processed with different cutting fluids were measured and compared.
| Cutting Fluid Type | Surface Roughness (Ra, μm) | Dimensional Accuracy (Deviation, μm) |
|---|---|---|
| Oil-Based | 0.8 | ±0.02 |
| Water-Based | 0.6 | ±0.01 |
3.3.2 Tool Life Analysis
The tool life was evaluated by measuring the number of workpieces processed before tool wear exceeded a certain threshold.
| Cutting Fluid Type | Tool Life (Number of Workpieces) |
|---|---|
| Oil-Based | 3000 |
| Water-Based | 4500 |
3.3.3 Environmental Protection and Cost Analysis
Water-based cutting fluids exhibit better environmental performance due to their lower impact on water bodies and soil. Additionally, their cost is lower due to reduced consumption and disposal costs.
4. Management and Maintenance of Cutting Fluids
Effective management and maintenance of cutting fluids are crucial for ensuring stable processing performance and prolonging tool life.
| Management Item | Oil-Based Cutting Fluid | Water-Based Cutting Fluid |
|---|---|---|
| Concentration Control | Regular testing and adjustment | Regular testing and adjustment |
| Filtration | Regular filter replacement | Regular filter replacement |
| Bacterial Control | Antibacterial agent addition | Antibacterial agent addition |
5. Evaluation and Optimization Methods for Gear Shaving Cutting Fluids in Green Manufacturing
5.1 Evaluation Method for Gear Shaving Cutting Fluids
A fuzzy comprehensive evaluation method was used to evaluate the processing results, considering processing time, quality, cost, resources, and environmental impact.
5.2 Case Analysis of Gear Shaving with Cutting Fluids
Comparative analysis was conducted on three types of cutting fluids: traditional oil-based, domestic microemulsion (semi-synthetic), and imported synthetic cutting fluid.
| Cutting Fluid Type | Evaluation Score |
|---|---|
| Traditional Oil-Based | 75.41 |
| Domestic Microemulsion (Semi-Synthetic) | 76.20 |
| Imported Synthetic | 80.21 |
The results show that both water-based cutting fluid schemes outperform the oil-based scheme. Considering cost, most enterprises prefer the domestic microemulsion for large-scale processing.
5.3 Optimization Scheme for Cutting Fluid Systems
The traditional cutting fluid supply system and its problems were analyzed, and an optimized scheme for process parameters was proposed.
6. Conclusion
This thesis proposes transitioning from oil-based to water-based cutting fluids in gear shaving to achieve greener manufacturing. Through experimental research, it evaluates the processing performance of different cutting fluids and proposes a comprehensive decision-making model for selecting and optimizing cutting fluids for green manufacturing. The results demonstrate that water-based cutting fluids outperform oil-based fluids in overall performance. Future research should focus on simplifying the evaluation method for cutting fluids, optimizing gear shaving process parameters, and developing more scientific and comprehensive evaluation methods to enhance processing efficiency.