Types of machine tool lubricants and how to choose the right one. Choosing the right machine tool lubricant is essential for ensuring smooth operation, extending equipment life, and maintaining machining accuracy. Different machine components and working conditions require different types of lubricants. Here’s a complete guide to the main types of machine tool lubricants and their applications.
1. Bearing Lubrication
Bearing lubrication is critical for minimizing friction, wear, and overheating.
- Sliding Bearings: Require low-viscosity lubricants with excellent anti-oxidation, anti-wear, and anti-rust properties. For example, spindle bearings on precision grinders often use bearing oil with a viscosity of 2.0 mm²/s.
- Rolling Bearings: Bearings with inner diameters below 25 mm and speeds under 30,000 rpm can use high-speed grease. For ultra-high-speed bearings, forced lubrication or oil mist lubrication is recommended to ensure reliability.
2. Gear Lubrication
Machine gears require lubrication to reduce wear and noise:
- Standard Gears: Ordinary gear oils are suitable for general machine tool gears.
- High-Impact Gears: For presses, shearing machines, or gears under heavy shock loads, gear oils with anti-wear additives are preferred. They should also provide oxidation resistance, corrosion protection, rust prevention, and foam suppression.
3. Guideway Lubrication
Guideways are crucial for precise machine movement:
- Commonly used guideway oils include ISO VG32, 68, 100, or 150.
- Oils containing anti-creep additives can reduce guideway “stick-slip” or crawling, improving machining accuracy. Brands like Sinopec guideway oils are widely used in the industry.
4. Hydraulic System Lubrication
Hydraulic systems require oils that protect components under high pressure:
- Anti-wear hydraulic oils (e.g., L-HM series) are standard.
- CNC machine tools demand high cleanliness levels. Recommended specifications include: flash point ≥120°C, pour point ≤-20°C, viscosity index ≥220, and cleanliness class 8.
5. Cutting and Machining Lubrication
Cutting fluids reduce tool wear and improve surface finish:
- Cutting oils with extreme pressure (EP) additives are ideal for turning, milling, and other machining operations.
- These oils enhance tool life, maintain precision, and produce smoother surfaces.
Key Considerations When Choosing Machine Tool Lubricants
- Different machine components require oils with specific viscosity and performance characteristics.
- Select lubricants based on working conditions such as speed, load, and temperature.
- Regularly monitor oil level and quality to ensure the lubrication system functions correctly.
Choosing the right machine tool oil improves efficiency, reduces maintenance costs, and ensures stable, high-quality machining results.