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Lubrication and Bearings

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Title: Lubrication and Bearings


1
Lubrication and Bearings
P H S A U T O M O T I V E S ALS
2
What is Friction
P H S A U T O M O T I V E S ALS
  • Friction - resistance to movement between two
    objects
  • The amount of friction depends on the following
    1. Material
  • 2. Surface finish
  • 3. Amount of pressure holding the two
    together 4. How fast they move

3
What is Friction
P H S A U T O M O T I V E S ALS
  • friction generates heatRub your hands together
    they get hot
  • dry friction - both parts clean and free of other
    materials
  • wet friction - parts have another material placed
    between them such as oil

4
What is a Bearing
  • A Bearing is a device used to support and guide a
    rotating, Oscillating, or sliding shaft or wheel.
  • A bearing is designed to
  • 1. Reduce friction
  • 2. Support a load
  • 3. Guide moving parts

5
Bearing construction
P H S A U T O M O T I V E S ALS
  • friction - sliding friction - two smooth surfaces
    sliding against each other
  • half speed bearing - turbos
  • anti friction - rolling friction - uses balls or
    rollers or small needles between the moving parts

6
Bearing construction
P H S A U T O M O T I V E S ALS
7
Bearing construction
P H S A U T O M O T I V E S ALS
  • Ball bearing

8
Bearing construction
P H S A U T O M O T I V E S ALS
  • Roller Bearing

9
Bearing construction
P H S A U T O M O T I V E S ALS
  • Tapered Roller Bearing

10
Bearing construction
P H S A U T O M O T I V E S ALS
  • Types of Roller Bearings

11
Bearing construction
P H S A U T O M O T I V E S ALS
  • needle

12
Bearing construction
P H S A U T O M O T I V E S ALS
  • Thrust Needle Ball

13
Bearing Load
  • If the wrong type of bearing is used it may not
    be able to carry the load that is applied to it.
    The load is dependent on both weight and
    direction.
  • There are Three types of loads.

14
Bearing Load (Radial)
  • The load is at right angles to the shaft.

15
Bearing Load (Thrust)
  • The load is Parallel to the shaft

16
Bearing Load (Angular)
  • The load is a combination of Radial and Thrust.

17
Bearing Failure
  • Premature bearing failures are caused by
  • 1. Fatigue (overloaded, under lubed)
  • 2. Poor lubrication (wrong type, under lubed)
  • 3. Contamination (dirt and water)
  • 4. Installation with the wrong tool
    (there is a correct tool for every job)

18
Full- Floating
19
Insert Bearings
  • removable bearing split in two pieces for easy
    installation and removal

20
Insert Bearings
  • steel back with soft lining, coating can be of
    babbitt, copper-lead-tin or aluminum coating
  • locating tabs help keeps insert bearing from
    turning

21
Insert Bearings
  • crush height the .001 to .002 protruding above
    rod cap and rod that when bolted together forms
    the tight fit that prevents the bearing from
    turning.

22
Insert Bearings
  • An undersize bearing is used on a crankshaft that
    has been machined to a smaller size.

23
BEARING PERFORMANCE
  • load strength- must withstand pounding from
    compression and firing stroke
  • anti scuffing - if oil pressure is lost lining
    must be soft enough to prevent crankshaft journal
    from being scratched or scuffed

24
BEARING PERFORMANCE
  • corrosion - must resist corrosion from vapors and
    acids in crankcase
  • conformation - must conform to shape of
    crankshaft journal

25
BEARING PERFORMANCE
  • embedability - must allow small particles to
    embed itself into bearing material so journal
    won't be scratched
  • temperature - must work equally well both hot
    and cold must transfer heat well
  • oil hole or groove for lubrication

26
BEARINGS
  • rod bearings, bearings in the connecting rod
  • main bearings, bearings that go where the main
    bearing cap hold the crankshaft in place.

27
THRUST BEARINGS
  • thrust bearing, has sides on to help prevent end
    play of crankshaft, sometimes use a separate
    piece for the side.

28
THRUST BEARINGS
29
4 Jobs of Oil
P H S A U T O M O T I V E S ALS
  • Cleans - Cools - Seals -Lubricates -

30
Bearing Clearance
P H S A U T O M O T I V E S ALS
  • Oil is pumped to the bearing and separates the
    parts. It allows the parts to turn without
    touching each other. When parts touch they will
    be destroyed.
  • bearing clearance average about .002

31
Bearing Clearance
32
How to lubricate a engine
P H S A U T O M O T I V E S ALS
  • engines lubricated three ways for a 4-stroke
    engine
  • Full pressure
  • Splash
  • Combination - splash and pressure- most common
    in automotive applications

33
Full pressure
P H S A U T O M O T I V E S ALS
  • bearings are oiled by pumping oil to the
    bearings, sometimes the oil is dripped on or is
    squirted on to parts

34
Splash
P H S A U T O M O T I V E S ALS
  • use of dippers on connecting rods to splash oil
    around (one cylinder engines) or dripping oil on
    the engine parts

35
Combination
P H S A U T O M O T I V E S ALS
  • both systems used- splash and pressure -
  • other methodstwo cycles mix gas and oilcould
    be premix or a oil injection system

36
Oil galleries and lines
P H S A U T O M O T I V E S ALS
  • Oil gallery - oil supply line in engine
  • oil is carried through the engine by these lines
  • some rods are drilled full lengths some have
    squirt holes

37
Oil filters
P H S A U T O M O T I V E S ALS
38
Oil filters
P H S A U T O M O T I V E S ALS
  • most common materialspaper and cotton waste
  • canister - old style
  • spin on

39
Filtering Systems
P H S A U T O M O T I V E S ALS
  • two types of filtering systems
  • full flow, all oil is filtered before going to
    bearings, filter has relief valve in case of
    plugged filter
  • bypass filter, part of oil is being filter at all
    times but not before it is going to the bearings

40
Oil pumps
P H S A U T O M O T I V E S ALS
  • gear, rotary, vane and plunger
  • most common automotive engine
  • gear and rotary

41
Gear
P H S A U T O M O T I V E S ALS
  • two gears mesh together forcing oil out

42
Rotary
P H S A U T O M O T I V E S ALS
  • inner rotor and outer rotor 4 points fit inside 5
    points

43
Vane
P H S A U T O M O T I V E S ALS
  • used as pump in some automatic transmissions(this
    one, a vane pump out of a air wrench)

44
Plunger
P H S A U T O M O T I V E S ALS
  • used a lot in one cylinder engines

45
Pick up tube and screen
P H S A U T O M O T I V E S ALS
46
Pressure Relief Valve
P H S A U T O M O T I V E S ALS
  • when oil pump develops too much pressure the
    Pressure Relief valve will open and allows to
    return to sump by changing spring tension
    pressure can be raised or lowered

47
Oil sludge
P H S A U T O M O T I V E S ALS
  • Black thick Goomixture of water oil dirt usually
    formed in engines never reaching operating
    temperature - thermostat taken out or to many
    short tripsformation of a white sludge - caused
    by, cold weather, short trips, too much water

48
Varnish or lacquer
P H S A U T O M O T I V E S ALS
  • usually known as engine varnish is formed from an
    engine running at hot temperature for extended
    periods - the heat causes the oil to break down
    and a varnish is created on valve covers and
    other parts to avoid varnish deposits use good
    clean oil and change regularly

Light brown coating is Varnish
49
Additives in oil
P H S A U T O M O T I V E S ALS
  • detergent - prevent sludge and varnish deposits
  • foam inhibitors - prevent oil from
    foamingoxidation inhibitors - prevent oil
    oxidation at high speed

50
Additives in oil
P H S A U T O M O T I V E S ALS
  • corrosion rust inhibitors - helps prevent these
  • anti wear additives - coat metal surfaces with a
    strong slippery film moly graphite

51
crankcase ventilation
P H S A U T O M O T I V E S ALS
  • draft tube
  • positive crankcase ventilation

52
open - draft tube
P H S A U T O M O T I V E S ALS
  • Older engines use a draft tube to vent the
    crankcase. It is just a vent with a filter in
    it. Uses a Breather cap to allow air in.

53
PCV - positive crankcase
P H S A U T O M O T I V E S ALS
  • open - breather cap
  • closedgoes from air cleaner to valve cover

54
wet and dry sump systems
P H S A U T O M O T I V E S ALS
55
windage tray
P H S A U T O M O T I V E S ALS
  • Bolt to bottom of engine prevent oil from foaming
    due to crankshaft rotation.

56
Oil viscosity
P H S A U T O M O T I V E S ALS
  • thickness or fluidity of the oil, oil's ability
    to resist flow
  • classified as a number such as 10,20,30,40
  • multi grade or multi viscosity 5w-30, 10w-30

57
service ratingsgo through handout
P H S A U T O M O T I V E S ALS
  • Go to this web site and read the classifications
  • http//www.lubrizol.com/ReadyReference/6-OilClasse
    s/Sclass.htm

58
how often should oil be changed,filter?
P H S A U T O M O T I V E S ALS
  • 1,000 - 7,500 average
  • About every 3,000 - 4,000 miles recommended
  • depends on length of operation, temperature of
    air and car. Condition of all filters - air, oil
    gas -, PCV valve, driving conditions, paved
    roads, and dust or dirt in the air.

59
what kind of oil should I buy ???
P H S A U T O M O T I V E S ALS
60
What kind of filter should I buy????
P H S A U T O M O T I V E S ALS
  • Some companies spent a lot of money on
    advertising and very little on filters, some just
    build good filters. You choose, cut some apart
    and look for yourself.

61
The End
P H S A U T O M O T I V E S ALS
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