Engine lubrication

Also found in: Dictionary, Thesaurus.

Engine lubrication

In an internal combustion engine, the system for providing a continuous supply of oil between moving surfaces during engine operation. This viscous film, known as the lubricant, lubricates and cools the power transmission components while removing impurities, neutralizing chemically active products of combustion, transmitting forces, and damping vibrations. See Internal combustion engine, Lubricant

Automotive engines are generally lubricated with petroleum-base oils that contain chemical additives to improve their natural properties. Synthetic oils are used in gas turbines and may be used in other engines. Probably the most important property of oil is the absolute viscosity, which is a measure of the force required to move one layer of the oil film over the other. If the viscosity is too low, a protecting oil film is not formed between the parts. With high viscosity too much power is required to shear the oil film, and the flow of oil through the engine is retarded. Viscosity tends to decrease as temperature increases. Viscosity index (VI) is a number that indicates the resistance of an oil to changes in viscosity with temperature. The smaller the change in viscosity with temperature, the higher the viscosity index of the oil.

Small two-stroke cycle engines may require a premix of the lubricating oil with the fuel going into the engine, or the oil may be injected into the ingoing air-fuel mixture. This is known as a total-loss lubricating system because the oil is consumed during engine operation.

Most automotive engines have a pressurized or force-feed lubricating system in combination with splash and oil mist lubrication. The lubricating system supplies clean oil cooled to the proper viscosity to the critical points in the engine, where the motion of the parts produces hydrodynamic oil films to separate and support the various rubbing surfaces. The oil is pumped under pressure to the bearing points, while sliding parts are lubricated by splash and oil mist. After flowing through the engine, the oil collects in the oil pan or sump, which cools the oil and acts as a reservoir while the foam settles out. Some engines have an oil cooler to remove additional heat from the oil. See Wear

References in periodicals archive ?
Marine power engine lubrication is one of the challenging applications for a lubricant where only the best engineered product can survive.
Heavy Duty Engine Lubrication - this course has been updated to include the latest information on on-highway applications using emission control systems, and an overview of CJ-4 oils
At an event in Jeddah Petromin Corporation, a major Saudi oil marketing company, launched its new Petropower Plus product range for marine power engine lubrication.
The new course addresses gasoline engine lubrication performance issues, provides an overview of commercial gasoline engine lubricants and offers a summary of lubricant performance specifications.
Parker Aerospace, a business segment of Parker Hannifin Corporation, the global leader in motion and control technologies, is developing an integrated engine lubrication system that simplifies system design and operation while reducing weight and package size on next-generation helicopters and small-engine aircraft.
It has a fully separated fuel system, dual hydraulic boost system, dual electrical systems and redundant transmission and engine lubrication and cooling systems.
To advance the cam, a valve is opened to allow high-pressure oil into the drive mechanism from the engine lubrication system.
An innovative two-stage oil pump will make BorgWarner a product leader in the European binary engine lubrication pump market and help BMW respond to the demand for greater engine efficiencies and fuel economy.
The Torque engine lubrication system includes a pair of lubrication galleries which extend through the engine block between the ends of the engine crankshaft and communicate with the crankshaft bearing journals through a plurality of lubrication passages.
Extensive testing of their products by our engine department has convinced us they offer the best in engine lubrication technology, and we look forward to many successful years together.
Also available is "Heavy Duty Engine Lubrication," which explains how a diesel engine operates, the key engine parts and its functions, the role of the lubricant, and how heavy diesel engine lubricants are specified.
Second is the Intelligent Warranty Program, Quaker State's 250,000-mile/10-year engine lubrication warranty, which is now transferrable and is expanded to include pre-owned vehicles.

Full browser ?