From Plant Engineer's Reference Book, Second Edition

40.8 Engine Lubricants

The type of power or fuel supply available will influence the decision on prime mover to be used. This is often electric power, but many items of plant such as compressors, generators or works locomotives, will be powered by diesel engines, as will most of the heavy goods vehicles used in and outside the works.

The oils for these engines have several functions to perform while in use. They must provide a lubricant film between moving parts to reduce friction and wear, hold products of combustion in suspension, prevent the formation of sludges and assist in cooling the engine. Unless the lubricant chosen fulfils these conditions successfully, deposits and sludge will form with a consequent undesirable increase in wear rate and decrease in engine life.

40.8.1 Frictional Wear

If the effects of friction are to be minimized, a lubricant film must be maintained continuously between the moving surfaces. Two types of motion are encountered in engines, rotary and linear. A full fluid-film between moving parts is the ideal form of lubrication, but in practice, even with rotary motion, this is not always achievable. At low engine speeds, for instance, bearing lubrication can be under boundary conditions.

The linear sliding motion between pistons, piston rings and cylinder walls creates lubrication problems which are some of the most difficult to overcome in an engine. The ring is exerting a force against the cylinder wall while at the same time the ring and piston are moving in the cylinder with...

Copyright Reed Educational and Professional Publishing Ltd 2002 under license agreement with Books24x7

Products & Services
Oil Additives and Fluid Additives
Oil additives and fluid additives are chemical substances that are added to oils and industrial fluids to impart or improve certain properties. They are used with lubricants, coolants, thermal oils, greases, metal working fluids, and other application-specific fluids.
Hydrostatic and Hydrodynamic Bearings
Hydrostatic bearings and hydrodynamic bearings are fluid film bearings that rely on a film of oil or air to create a clearance between the moving and stationary elements.
Combustion Engines
Industrial engines are heavy-duty, internal combustion engines that are used to power and propel vehicles, machinery, and equipment. They burn a liquid or gaseous fuel such as gasoline, diesel, biodiesel, propane, or natural gas.
Mechanical Vacuum Pumps and Systems
Mechanical vacuum pumps and systems contain devices such as pistons, claws, scrolling spirals, and diaphragms to isolate and compress air.
Piston Rings
Piston rings are used for sealing cylinders.  They can work at higher temperatures than elastomeric, fabric, or polymer seals.

Topics of Interest

40.9 Gear Lubricants There are few engineering applications in which gears do not play an essential part. They can be used to reduce or increase speed, transmit power and change the direction or...

24.1 Introduction Lubricants minimise friction and wear in rubbing contacts by reducing metal-metal contact, removing wear debris, and carrying away frictional heat. They may also prevent rusting and...

All material surfaces, hard or soft, have many irregularities in the form of asperities known as peaks and valleys. When two solid surfaces pass over each other, the asperities of both surfaces come...

Lubrication plays a vital role in the performance and life of rolling element bearings. The most important task of the lubricant is to separate parts moving relative to one another (balls or rollers...

Marine engine manufacturers are faced with the constant and difficult challenge of designing and building engines to operate under the most severe environments, engines that must be long lasting,...