1 22/02/2005Strategic's Annual Reliability Conference Bearing Damage Analysis Jonathan Brown Manager IOE & Rail Australian Timken Phone: Fax:

2 22/02/2005Strategic's Annual Reliability Conference Bearing Life u Theoretical (rated) Bearing Life u L10 Life Calculations u Load u Revolutions u “Actual” bearing life

3 22/02/2005Strategic's Annual Reliability Conference Bearing Damage u To achieve rated life, bearings must be correctly: u Selected u Installed u Handled u set u lubricated u Maintained

4 22/02/2005Strategic's Annual Reliability Conference Tapered Roller Bearing Cone Cage Rollers Cup

5 22/02/2005Strategic's Annual Reliability Conference Bearing Loads u Axial and thrust loads combine to create seating force u Keeps rollers perfectly aligned u The cage keeps the rollers equally spaced around the cone

6 22/02/2005Strategic's Annual Reliability Conference Bearing Clearance (Setting) Axial Clearance u Adjustable Setting u Adjust clearance between races and rollers u Maximize machine performance and extend bearing life

7 22/02/2005Strategic's Annual Reliability Conference Tapered Bearing Adjustment

8 22/02/2005Strategic's Annual Reliability Conference Life vs Bearing Setting at operating conditions

9 22/02/2005Strategic's Annual Reliability Conference Two Types of Contact Rolling and Sliding Contact Rolling Contact

10 22/02/2005Strategic's Annual Reliability Conference Bearing Damage u As many as 95% of bearing failures occur prior to achieving the design life of the bearing u You need diagnose bearing failures to recommend corrective action

11 22/02/2005Strategic's Annual Reliability Conference Spalling – The end of “design” life

12 22/02/2005Strategic's Annual Reliability Conference Spalling u Cyclic fatigue

13 22/02/2005Strategic's Annual Reliability Conference Spalling u Occur at site of non-metallic inclusion u Dirt particle u Graphite stringer u Alumina stringer

14 22/02/2005Strategic's Annual Reliability Conference Inclusion-origin spall

15 22/02/2005Strategic's Annual Reliability Conference Inclusion-origin spall u Normal life criteria inclusion-origin spall

16 22/02/2005Strategic's Annual Reliability Conference Inclusion-origin spall u Spall propagation

17 22/02/2005Strategic's Annual Reliability Conference Inclusion-origin spall u Spall Propagation

18 22/02/2005Strategic's Annual Reliability Conference Point surface-origin spall u Caused by nicks, scratches, dents

19 22/02/2005Strategic's Annual Reliability Conference Point surface-origin spall u Typical, axial propagation

20 22/02/2005Strategic's Annual Reliability Conference Misalignment

21 22/02/2005Strategic's Annual Reliability Conference Misalignment u Even load distribution

22 22/02/2005Strategic's Annual Reliability Conference Misalignment u Stress on small end

23 22/02/2005Strategic's Annual Reliability Conference Misalignment

24 22/02/2005Strategic's Annual Reliability Conference Misalignment u Misaligned housing bores

25 22/02/2005Strategic's Annual Reliability Conference Misalignment HOUSING BORE SHAFT

26 22/02/2005Strategic's Annual Reliability Conference Misalignment u Uneven wear

27 22/02/2005Strategic's Annual Reliability Conference Misalignment u Uneven wear

28 22/02/2005Strategic's Annual Reliability Conference Misalignment u Geometric stress concentration spall

29 22/02/2005Strategic's Annual Reliability Conference Misalignment u Geometric stress concentration spall

30 22/02/2005Strategic's Annual Reliability Conference Misalignment u Split housings

31 22/02/2005Strategic's Annual Reliability Conference Misalignment

32 22/02/2005Strategic's Annual Reliability Conference Misalignment

33 22/02/2005Strategic's Annual Reliability Conference Foreign Material

34 22/02/2005Strategic's Annual Reliability Conference Foreign Material u Abrasive wear

35 22/02/2005Strategic's Annual Reliability Conference Foreign Material u Bruising

36 22/02/2005Strategic's Annual Reliability Conference Foreign Material u Bruising

37 22/02/2005Strategic's Annual Reliability Conference Foreign Material u Grooving

38 22/02/2005Strategic's Annual Reliability Conference Handling Damage

39 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Deformed cage

40 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Deformed cage

41 22/02/2005Strategic's Annual Reliability Conference Handling Damage u “Spiral Bevel Bearing”

42 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Roller-spaced nicking

43 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Roller nicking

44 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Random nicks

45 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Gouging

46 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Cup edge damage

47 22/02/2005Strategic's Annual Reliability Conference Handling Damage u Cup edge damage

48 22/02/2005Strategic's Annual Reliability Conference Brinelling u True brinnelling: Roller-spaced indents caused by incorrect handling or shock loads

49 22/02/2005Strategic's Annual Reliability Conference Brinelling

50 22/02/2005Strategic's Annual Reliability Conference Brinelling u Grind marks evident in indent

51 22/02/2005Strategic's Annual Reliability Conference Brinelling u False brinnell (fretting)

52 22/02/2005Strategic's Annual Reliability Conference Brinelling u False brinnell (fretting)

53 22/02/2005Strategic's Annual Reliability Conference Brinelling FalseTrue

54 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems

55 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Caused by: u Insufficient lubricant u Absence of lubricant u Wrong kind of lubricant u Areas to check: u Roller ends u Cone large rib

56 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Scored rollers

57 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Heat discolored rollers

58 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Scoring and metal flow

59 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Scored cone rib

60 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Discolored cup

61 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Skewed rollers

62 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems

63 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems u Metal transfer

64 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems

65 22/02/2005Strategic's Annual Reliability Conference Lubrication Problems

66 22/02/2005Strategic's Annual Reliability Conference Excessive Preload or Overload u Usually looks much the same as inadequate lubrication damage u Bearing components are forced tightly together u Lube film is squeezed out creating metal to metal contact

67 22/02/2005Strategic's Annual Reliability Conference Excessive Preload or Overload

68 22/02/2005Strategic's Annual Reliability Conference Excessive Preload or Overload u Peeling

69 22/02/2005Strategic's Annual Reliability Conference u Advanced peeling Excessive Preload or Overload

70 22/02/2005Strategic's Annual Reliability Conference Excessive Preload or Overload u Full race-width spalling

71 22/02/2005Strategic's Annual Reliability Conference Excessive Preload or Overload

72 22/02/2005Strategic's Annual Reliability Conference Excessive Endplay u Components are not seated tightly against one another u Rollers are too loose in and out of the load zone u Rollers contact cage small ends of pockets u Cage wear

73 22/02/2005Strategic's Annual Reliability Conference Excessive Endplay

74 22/02/2005Strategic's Annual Reliability Conference Excessive Endplay

75 22/02/2005Strategic's Annual Reliability Conference Excessive Endplay u Scalloping

76 22/02/2005Strategic's Annual Reliability Conference Water / Etch Damage

77 22/02/2005Strategic's Annual Reliability Conference Water / Etch Damage u Condensation in the bearing housing u Temperature change u Inadequate seals u Improper washing and drying u Three stages

78 22/02/2005Strategic's Annual Reliability Conference Water / Etch Damage u Staining

79 22/02/2005Strategic's Annual Reliability Conference Water / Etch Damage u Etching / Rusting

80 22/02/2005Strategic's Annual Reliability Conference Water / Etch Damage u Etching  Roller-spaced Spalling

81 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage

82 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage u Tiny arcs of electricity jump from rollers to races u Causes small burns u Electric arc pitting u Electric arc fluting

83 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage

84 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage

85 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage u Pitting

86 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage u Pitting

87 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage u Fluting

88 22/02/2005Strategic's Annual Reliability Conference Electrical Arc Damage

89 22/02/2005Strategic's Annual Reliability Conference Long, trouble free bearing performance u Cleaning u Handling u Setting u Lubrication u Sealing

90 22/02/2005Strategic's Annual Reliability Conference Understanding Damage Analysis u Get all the components and information possible u In a two-bearing system, get both bearings u Also get any gears, seals, mounting components u Lube samples are helpful

91 22/02/2005Strategic's Annual Reliability Conference Bearing Damage Analysis