Lubricant categories
Based on the different uses of lubricants we distinguish the following broad categories:
More specifically:
ENGINE LUBRICANTS
They are mineral, synthetic or semisynthetic depending on the nature of the base lubricant (mineral, synthetic, or a mixture)
Their formal composition is:
- Bases / 70-95%
- Improvers additives / 5-20%
- Viscosity modifier /0-20%
- Various additives / 0-2%
Basic factors of quality control:
- Cold start simulator,
- Viscosity index,
- Total base number (ΤΒΝ),
- Approvals of manufacturers
TRANSMISSION LUBRICANTS
- Gear and differential boxes
- Off road (UTTO, CAT)
- Automatic transmission fluids
Basic quality factors:
- Internal cooling of the tools from the heat transfer to the gearbox or separate oil containers
- Antifoam protection and protection from corrosion, wear and deposits
- Stability in acidity
- Elastomer compatibility
- Friction characteristics compatible with synchronizer materials to ensure optimal gear ratio
- High protection from pressures
- Rheological characteristics at low temperatures (especially for automatic transmission fluids)
- High viscosity index (especially for automatic transmission fluids)
Outstanding anti-foaming behaviour and air release speed to ensure correct operation of the hydraulic unit.
HYDRAULIC LUBRICANTS
In hydraulic lubricants the amount of additives is only 0.5 – 2.0%. A good quality hydraulic lubricant is a special additive mixture with high quality base lubricants.
Basic quality factors:
- Appropriate viscosity
- Thermal stability at high operating temperatures, which acts suspensively towards the acidity of the lubricant
- Anti-foaming properties for protection from foaming and air entrapment, which are responsible for various issues such as irregular operation of the hydraulic system and loss of control or vibrations, acidity of the lubricant, etc.
- Protection from rust and corrosion
- Compatibility with seals
- Permeability filter that determines the “degree” of the lubricant’s purity where this property is required.
- Weaning possibility (separation and pumping from water), as the water in the hydraulic system can cause corrosion, cavitation of pumps, problems in filters, and other undesirable issues.
- Oxidative stability
- Resistance to wear
- Acidity (ΤΑΝ)
- Approvals of machinery manufacturers
OTHER LUBRICANTS OF INDUSTRIAL USES
Industry uses specialized lubricants depending on its use and production. We distinguish lubricants for:
- Textile
- Reducers
- Transformers
- Metal cutting
- Slides
- Air Compressors and turbochargers
- Cooling machines
- Heat transfer
- Food and beverage industry
- Chains and wire ropes
- Circulatory systems
- Machine tools
- Special uses
The greatest mission of lubrication is to effectively reduce the friction between two friction surfaces, reducing in this way the wear and maximizing their lifespan, but also economy over time. The maintenance engineer in an industry makes every effort to achieve maximum availability of machines by minimizing their damage. In this endeavor lubrication constitutes a very important sector, because even the best preventive maintenance plan will fail without properly organized lubrication. The right lubricant, in the right place, the right time and the right amount constitutes the quintessence of the properly organized lubrication of every machine.