1、Piston Engines 2Engine LubricationHomePreviousNextHelpAgenda - Lubrication Review engine air and liquid cooling and associated components Describe functions of lubricants: Describe characteristics of engine lubricants: Describe common standards and specifications for lubricants: Explain advantages a
2、nd disadvantages of different lubricants Explain Precautions when intermixing oil types Describe types of lubrication systems Wet Sump Dry Sump Describe external components of reciprocating engine oil lubrication system Describe methods for internal lubrication of reciprocating engines Describe main
3、tenance practices for reciprocating engine oil lubrication systemsHomePreviousNextHelpReview Engine Cooling Systems Air Cooling: transfers heat of engine from to the air passing through cooling fins on cylinders directed by cowlings, baffles and baffle seals. Liquid cooling: transfers heat from engi
4、ne to liquid medium (oil or engine coolant) and then heat is extracted from cooling medium by passing it through a radiator (liquid to air heat exchanger)HomePreviousNextHelpAir Cooling SystemHomePreviousNextHelpLiquid Cooling SystemHomePreviousNextHelpLiquid Cooling SystemHomePreviousNextHelpFuncti
5、ons of Lubricant Friction caused by metal to metal contact Cooling extracting heat from various engine components Sealing elimination of gaps or spaces between components Cushioning absorbing of impact or pounding force Cleaning removal of contaminants Corrosion build up of oxidants (common term is
6、rust)HomePreviousNextHelpFriction Any two moving engine components contacting each other will generate friction This friction is caused by surface imperfections such as microscopic peaks and valleys By coating the two components with a thin film of engine oil, the peaks and valleys are filled in and
7、 friction is reduce Height of these imperfections and clearance between components will determine how thick or viscose the oil must be.HomePreviousNextHelpFrictionHomePreviousNextHelpCooling Conduction of heat energy from hot engine parts into oil film bathing parts will cool parts. Oil then must be collected or removed from area and cooled Heated oil is transferred to an oil air heat exchanger (oil cooler) to cool oil Fresh cooled oil applied to hot components helps to control component temperature
