Engine Construction and Principles of Operation Chapter 4

  • Slides: 31
Download presentation
Engine Construction and Principles of Operation Chapter 4

Engine Construction and Principles of Operation Chapter 4

Objectives n Explain simple engine operation. n List the qualities of gasoline that make

Objectives n Explain simple engine operation. n List the qualities of gasoline that make it an efficient fuel for small engines. n Explain why gasoline is atomized in the small engine. n Identify the basic components of a small engine and describe the function of each part.

How does an Engine Work?

How does an Engine Work?

Gasoline n Hydrocarbon fuel (mix of hydrogen and carbon) n Gas should n Ignite

Gasoline n Hydrocarbon fuel (mix of hydrogen and carbon) n Gas should n Ignite readily, burn cleanly, resist detonation n Vaporize easily w/o vapor lock n Free of dirt, water, and abrasives

Octane Number n Ability to resist detonation n Low Compression = Regular n High

Octane Number n Ability to resist detonation n Low Compression = Regular n High Compression = Premium n Video 1 n Video 2

Octane Number n Lead n Oxygenates n Ethanol

Octane Number n Lead n Oxygenates n Ethanol

How does gasoline burn? n Liquid? n Vapor? n Atomizing

How does gasoline burn? n Liquid? n Vapor? n Atomizing

Containing Our Explosion n Minimizing Lost Energy n Combustion Chamber

Containing Our Explosion n Minimizing Lost Energy n Combustion Chamber

Questions on Page 71

Questions on Page 71

Cylinder Block n Keeps all parts aligned n Cast Iron n Aluminum Alloy

Cylinder Block n Keeps all parts aligned n Cast Iron n Aluminum Alloy

Cooling Fins n Function n Design

Cooling Fins n Function n Design

Crankshaft n Major rotating part of the engine n Forged or Cast Steel with

Crankshaft n Major rotating part of the engine n Forged or Cast Steel with precisely machined and ground bearings

Crankshaft n Counterweights n Crankpin or Connecting Rod Journal n Throw n Flywheel n

Crankshaft n Counterweights n Crankpin or Connecting Rod Journal n Throw n Flywheel n PTO

Crankcase n Rigid and Strong n Keep Parts Aligned n Hold Oil and Keep

Crankcase n Rigid and Strong n Keep Parts Aligned n Hold Oil and Keep Out Dirt

Piston n Straight line driving member of the engine n Subject to direct heat

Piston n Straight line driving member of the engine n Subject to direct heat from combustion

Piston n Adequate clearance to allow for expansion n Piston rings n Compression Ring:

Piston n Adequate clearance to allow for expansion n Piston rings n Compression Ring: n Scraper Ring (Compression): n Oil Ring:

Piston n Ring grooves n Characteristics of a Piston n Wrist Pin (Piston Pin):

Piston n Ring grooves n Characteristics of a Piston n Wrist Pin (Piston Pin): n Retainers

Connecting Rod n Connects piston to crankshaft n Bearings n Bearing Cap

Connecting Rod n Connects piston to crankshaft n Bearings n Bearing Cap

Intake and Exhaust Ports n Ports (Two Stroke) n Poppet Valves

Intake and Exhaust Ports n Ports (Two Stroke) n Poppet Valves

Poppet Valves n Intake (Usually Larger): n Exhaust:

Poppet Valves n Intake (Usually Larger): n Exhaust:

Poppet Valves n Valve Face n Valve Seat n Valve Stem

Poppet Valves n Valve Face n Valve Seat n Valve Stem

Poppet Valves n Valve Guide n Valve Spring n Valve Rotator n Retainer (Keeper)

Poppet Valves n Valve Guide n Valve Spring n Valve Rotator n Retainer (Keeper) n Pin n Collar n Keyhole

Valve Lifter or Tappet n Link b/w camshaft lobe and valve stem

Valve Lifter or Tappet n Link b/w camshaft lobe and valve stem

Camshaft n Timing Gear n Lobe n Compression Release n Position?

Camshaft n Timing Gear n Lobe n Compression Release n Position?

Flywheel n Three Functions n Momentum n Cooling n Ignition/Accessories

Flywheel n Three Functions n Momentum n Cooling n Ignition/Accessories

Objectives n Explain simple engine operation. n List the qualities of gasoline that make

Objectives n Explain simple engine operation. n List the qualities of gasoline that make it an efficient fuel for small engines. n Explain why gasoline is atomized in the small engine. n Identify the basic components of a small engine and describe the function of each part.