ENGINE LUBRICATING OIL SYSTEMS

Lubrication is as important for reliable engine operation as air, fuel, and heat are to combustion. Lubrication is considered to be one of the most important factors in the operating life of an internal-combustion engine. The lubrication requirements of shipboard machinery are met in various ways, depending on the design of the machinery. It is important not only that the proper type of lubricant be used, but also that the lubricant be supplied to the engine parts at the specified flow rate and temperature and that provisions be made for removal of any impurities that enter the system.

After studying the information in this chapter, you should be able to understand the basic theories of lubrication, the fac-tors affecting lubrication, the functions and characteristics of greases and lubricating oils used aboard ship, and the design and func-tion of components in various lubricating oil systems, including tanks, pumps, coolers, and filtering devices that you, as an Engine-man, may be required to operate or main-tain. You should also be able to understand the importance of standards and procedures and how they are established and enforced through the Lube Oil Quality Management Program.

For proper operation of an engine, the contacting surfaces of all moving parts of the engine must be prevented from touching each other so that friction and wear can be reduced to a minimum. Sliding contact between two dry metal surfaces under load will cause excessive friction, heat, and wear. Friction, heat, and wear can greatly be reduced, of course, if metal-to-metal contact is prevented. When a clean film of lubricant is used between the metal surfaces, metal-to-metal contact is automatically reduced. The lubricating film used between load bearing surfaces in machinery is provided by a specified oil or grease.