Industrial Lubricant reduces friction between moving surfaces. The property of reducing friction is known as lubricity. A good lubricant exhibits various characteristics like
- High boiling point
- Low freezing point
- High viscosity index
- Thermal stability
- Corrosion prevention
- High resistance to oxidation
The main use of lubricants is in the form of motor oil. It is used to shield the internal combustion engines in motor vehicles and powered equipment.
In general, lubricants are a combination of 90% base oil and less than 10% additives. Vegetable oils or synthetic liquids such as hydrogenated polyolefin, esters, silicones, fluorocarbons and many others are sometimes used as base oils. Additives are the substances that deliver reduced friction and wear, resistance to corrosion and oxidation, aging or contamination etc.
There are different types of industrial lubricants starting from hydraulic oils, circulating oils, gear oils to non-liquid lubricants like grease, powders etc. Equipment that might use hydraulic fluids are excavators and backhoes, hydraulic brakes, power steering systems, transmissions, garbage trucks, aircraft flight control systems, lifts, and industrial machinery. Common hydraulic fluids are manufactured from mineral oil or water.
Brake oil comes under the genre of hydraulic oils. They display high boiling point. Under the heat of braking, both free water and water vapor in a braking system can boil into a compressible vapor, resulting in brake failure. Glycol-ether based fluids are hygroscopic, and absorbed moisture will reduce the boiling point over time. Non-liquid lubricants consist of grease, powders (dry graphite, PTFE, Molybdenum disulfide, tungsten disulfide, etc.), PTFE tape used in plumbing, air cushion and others. Dry lubricants such as graphite, molybdenum disulfide and tungsten disulfide provide lubrication at temperatures higher than liquid and oil-based lubricants.
Functions of industrial lubricants are:
- Keep moving parts apart: The lubricant reduces friction and surface fatigue, together with reduced heat generation, operating noise and vibrations.
- Transfer heat: Circulating oil is constantly moving from a cooler part of the system to the remaining parts. Lubricants may be used to warm as well as to cool the system as per the requirement.
- Carry away contaminants and debris: They can carry away internally generated debris and external contaminants that enter into the system to a filter where they can be removed.
- Transmit power: Lubricants like hydraulic fluid are used as the working fluid in hydrostatic power transmission.
- Protect against wear: They keep the moving devices apart preventing wear.
- Prevent corrosion and rust
- Seal for gases: They fill the space between moving parts through the capillary force, thus sealing the clearance.
- Stop the risk of smoke and fire of objects: This function provides safety.
