types of lubrication system in ic engines pdf

Modern automotive lubricants contain as many as ten additives, comprising up to 20% of the lubricant, the main families of additives are: Limited interest has been shown in low friction properties of compacted oxide glaze layers formed at several hundred degrees Celsius in metallic sliding systems, however, practical use is still many years away due to their physically unstable nature.Ī large number of additives are used to impart performance characteristics to the lubricants. Dry lubricants such as graphite, molybdenum disulphide and tungsten disulphide also offer lubrication at temperatures (up to 350 ☌) higher than liquid and oil-based lubricants are able to operate. Non-liquid lubricants include powders (dry graphite, PTFE, molybdenum disulphide, tungsten disulphide, etc.), PTFE tape used in plumbing, air cushion and others. Additives deliver reduced friction and wear, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc. Vegetable oils or synthetic liquids such as hydrogenated polyolefins, esters, silicones, fluorocarbons and many others are sometimes used as base oils. Typically lubricants contain 90% base oil (most often petroleum fractions, called mineral oils) and less than 10% additives. A high boiling point and low freezing point (in order to stay liquid within a wide range of temperature).Properties Ī good lubricant generally possesses the following characteristics: This technology allowed the purification of very nonvolatile substances, which are common in many lubricants. A breakthrough came with the development of vacuum distillation of petroleum, as described by the Vacuum Oil Company. Relying initially on natural oils, needs for such machinery shifted toward petroleum-based materials early in the 1900s. The growth of lubrication accelerated in the Industrial Revolution with the accompanying use of metal-based machinery. In the Roman era, lubricants were based on olive oil and rapeseed oil, as well as animal fats. Building stones were slid on oil-impregrated lumber in the time of the pyramids. Calcium soaps have been identified on the axles of chariots dated to 1400 BC. Lubricants have been in some use for thousands of years.

6 'Glaze' formation (high-temperature wear).

Types of lubrication system in ic engines pdf