ML20043F676
| ML20043F676 | |
| Person / Time | |
|---|---|
| Issue date: | 02/12/2020 |
| From: | Office of the Chief Human Capital Officer, Woodard Corp |
| To: | |
| Gary Callaway | |
| Shared Package | |
| ML20043F634 | List:
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| References | |
| Download: ML20043F676 (28) | |
Text
Chapter 5 ENGINE LUBRICATION SYSTEM
Learning Objectives:
As a result of this chapter, you will be able to:
- 1. Define lubrication and the types of friction.
- 2. State the diesel engine lubrication system functions.
- 3. Identify the major components of a typical engine lubrication system and trace the flow path of lube oil through the engine.
- 4. State the purpose and describe operation of lube oil keep warm and pre-lube system(s) commonly used on NPP diesel engines.
Lubrication Fundamentals Lubrication is defined as the application of lubricants to minimize friction between moving contact surfaces.
Friction is the force that acts at the contact surface between two bodies which causes resistance to their relative motion.
Forced movement of adjacent surfaces can wear them away and also create heat, as illustrated in Figure 5-1.
Types of friction are illustrated in Figures 5-2 and 5-3.
Figure 5-1 Frictional Surfaces
Figure 5-2 Types of Friction
Figure 5-3 Rolling Friction Lubrication to achieve fluid friction is accomplished by lubricant wedge formation with laminar flow of the lubricant between the surfaces, as illustrated in Figures 5-4 and 5-5. Application of this principle to the crankshaft is illustrated in Figure 5-6.
Figure 5-4 Laminar Action Figure 5-5 Wedge Formation Figure 5-6 Shaft and Bearing
Lubrication Functions Maintain a film of lubrication between moving parts Create a gas tight seal between the piston rings and cylinder wall Remove and dissipate heat Keep surfaces clean
Lubricants properties must be as specified by the EDG manufacturer including:
Viscosity (varies with temperature)
Viscosity Index (no multi-viscosity oils)
Pour Point Oxidation Resistance - TBN/TAN numbers Naphthenic versus Paraffinic Lubricants Specific Manufacturers Lubricant (in some cases)
A typical lube oil circulating and cooling system is shown in Figure 5-7. Details of some components are shown on Figures 5-8 through 5-12.
Figure 5-7 Lube Oil Circulating and Cooling System Figure 5-8 Lubricating Oil Pump
Figure 5-9 Lubricating Oil Filters
Figure 5-10 Lubricating Oil Cooler Figure 5-11 Pressure Relief Valve
Figure 5-12 Pressure Regulating Valve A typical lube oil system with keepwarm added is shown in Figure 5-13.
The main Pielstick engine lube system is Figure 5-14 (for bearings, conrods, pistons, cylinders, etc.)
A separate Pielstick lube system for its rocker arms is shown in Figure 5-15.
Figure 5-13 Lube Oil System with Keepwarm Added Figure 5-14 Pielstick Engine Lube Oil Flow
Figure 5-15 Pielstick Valve Rocker Flow
Lube Oil System Monitoring Pressures and temperatures in lubrication systems are monitored, and displayed on the engine control panel.
Some other data of relevance to the lube oil system may also be monitored, as follows:
Crankcase pressure (vacuum): Rise in crankcase pressure can indicate serious engine problems, likely lube-related.
A special sensor to monitor that is shown in Figure 5-16.
Main bearings temperatures: Rise in bearing temp may also indicate a serious engine problem, likely lube-related.
A sensor for that purpose is shown in Figure 5-17.
Figure 5-16 Diaphragm-Type Crankcase Pressure Monitoring Switch Figure 5-17 Bearing Temperature Probe Figure 5-18 Crankcase Explosion Relief Device END OF CHAPTER 5