Bearing Engineering Guide

Engineering Guide

 

 

Bearing Identification System

 

  1 2 3 4 5 6 7 8 9 10
SERIES Material Type Style Basic Size Special Feature Closures Ring Feature ABEC Tolerance Radial Play Lubrication
METRIC

M

F

-

105

X

ZZ

EE

A3

MC3

LO1

INCH

S

F

R

156

X

ZZ

EE

A3

MC3

LO1

 

1

Material (M) (S)
Symbol M or Blank denotes SUJ2 (SAE52100) Chrome Steel.
Symbol S denotes SUS440C (AIS1440C) Stainless Steel.

2

Type (F)
Symbol F is used to designate a Flanged bearing is required.

3

Style (R)
Symbol R is used for all miniature and instrument bearings to signify Single Row Radial Retainer Type.

4

Basic Size (105) (156)
Symbol R is used for all miniature and instrument bearings to signify Single Row Radial Retainer Type.

5

Special Features (X)
Symbol X is used to designate a change in the standard bearing size.

6

Closures (ZZ)
The following symbols designate available closures. 
No designation denotes and Open style bearing.
Z-Single Shield, RS-Single Rubber Seal, 
VV-Double Non-Contact Seals
ZZ-Double Shield, 2RS-Double Rubber Seals, 
ZZS-Removable Seals
Z1-Shield on Flange Side, Z2-Shield Opposite Flange Side

7

Ring Feature (EE)
Symbol EE is used when the Extended Inner Rings are required.

8

ABEC Tolerances (A3)
AFBMA Standards: A1-ABEC1, A3-ABEC3, A5-ABEC5, A7-ABEC7
ISO Standards: P0(A1) P6(A3) P5(A5) P4(A7)

9

Radial Play (MC3)
Symbol MC3 followed by numbers indicates the range of radial play.
Example: MC3=0.005-0.013mm (0.0002 to 0.0005 inch)
Example: MC4=0.013-0.020mm (0.0005 to 0.0008 inch)
Symbol C designates larger size metric bearings.

10

Lubrication (LO1) - blank denotes manufacturer option
All bearings supplied with manufacturer's standard lubrication. 
LO followed by number indicates specific oil lube. 
LG followed by number indicates specific grease lube.
LD denotes dry bearings.
For specific lubrication, refer to the Lubrication Guide.

 

 

Cage & Retainer Types

W : ONE-PIECE STEEL CROWN TYPE

J : TWO-PIECE STEEL RIBBON TYPE

RJ : TWO-PIECE STEEL RIVET TYPE

TW : ONE-PIECE NYLON CROWN TYPE

V : FULL COMPLEMENT OF BALLS

The stainless steel pressed cage is inner ring guided. It shows excellent performance in low torque, low speed applications

Consists of two mating steel pressings, the cover side and the finger side. Usually guided by the rolling elements and designed to reduce frictional torque.

The RJ type cage is suitable for larger bearings with a high load carrying capacity. The two pieces are riveted together and are strong enough to withstand higher levels of vibration and acceleration. The cage is guided by the balls and reduces frictional torque.

Molded nylon cage. Reduces the fluctuation in running torque. Suitable for high speeds.
Guided by the rolling elements.

This type of bearing has no cage but maximum possible number of balls. Due to the fact that the inner and outer ring have a filling slot, the axial load carrying capacity of this bearing type is low. This type of bearing is suitable for high radial load, low speed applications.

 

 

Design & Characteristics of Radial Ball Bearings

BEARING STRUCTURE

BEARING DESIGN

Standard

(EE) Extended Inner Ring

(V) Full Complement

(N) With Snap Ring Groove

(NR) With Snap Ring Groove and Snap Ring

(F) With Flanged Outer Ring

 

BEARING CHARACTERISTICS
Load: Single row radial ball bearings with ball separated by a cage can support radial loads, axial loads and tilting movements. All full complement V-type ball bearing can support only radial loads and some low axial loads.
Speed: Maximum permissible speeds for ball bearings are mainly related to the bearing design and size, cage type, bearing internal clearance, the method and type of lubrication, manufacturing accuracy, sealing methods and loads.
Torque & Noise Level: Single row radial ball bearings are precision components and have low torque and noise levels.
Inclination of Inner/Outer Rings: Shaft and housing seats with poor accuracy, fitting errors and shaft bending might cause inclination between the inner and outer rings, although the internal clearance of the bearing will permit this to a certain extent. Generally, the maximum permissible inclination between the inner and out rings is approximately 1 in 300.
Toughness: Bearings under load deform elastically at the contact point between the rolling element and bearing ring. This is influenced by the bearing type, size, form and load.
Installation & Removal The single row radial ball bearing is a non-separable bearing. Therefore, shafts and housings should be so designated to enable bearing inspection and replacement when necessary.
Axial Location: Improved axial location is obtained with NR and F type bearings

 

BEARING DESIGN MATERIAL
Standard material for rings and balls is a vacuum degassed high carbon chromium steel allowing for high efficiency, low torque, low noise level and long bearing life. For bearings requirng anti-corrosion or heat-resistance properties, marensitic stainless steel is used.
CHEMICAL COMPOSITION OF BEARING MATERIAL

Materials

Symbol

Chemical Composition %

Equivalent

C

Si

Mn

P

S

Cr

Mo

High Carbon Chromium Steel SUJ2 0.95~1.10 0.15~0.35 <=0.50 <=0.025 <=0.025 1.30~1.60 <=0.08 SAE52100
Stainless Steel SUS440C 0.95~1.20 <=1.00 <=1.00 <=0.040 <=0.030 16.00~18.00 <=0.75 AISI440c

 

ZZ: Pressed Steel Shield

ZZS Presseed Steel Shield

TTS Teflon Seal w/ Snap Ring

2RS Contact Rubber Seal

Non Contact Rubber Seal

Non-contact shield pressed into outer ring. Non-contact shield retained in outer ring. (Removable) Non-contact shield retained in outer ring. (Removable) Rubber seal fitted into outer ring. Non-contact rubber seal fitted into outer ring

 

 

Industry Engineering Lube

Common Oil Brands and Efficiency

MANUFACTURER

BRAND

OUR CODE

LUBRICATION BASE

FLASH POINT ºC

VISCOSITY

OPERATING TEMP. ºC

MIL STANDARD

SHELL OIL AERO SHELL FLUID 12* AF2 DIESTER 235 14(38ºC) -50 TO +120 MIL-L-6085A
SHELL OIL AERO SHELL FLUID 3 AF3 PETROLEUM 145 10.2(40ºC) -55 TO +115 MIL-L-7870A
ANDERSON OIL WINDSOR LUBE L-245X WL2 DIESTER 215 14(38ºC) -55 TO +175 MIL-L-6085A
TENNECO CHEMICALS ANDERSOLL-401D A4D DIESTER 220 12.7(38ºC) -60 TO +125 MIL-L-6085A
DOW CORNING SH550R D5R METHYLPHENYL 316 125(25ºC) -40 TO +230  -
NIHON OIL CO. ANTIRUST P2100 002 166 13(40ºC)  - VV-L-800



Common Grease Brands and Efficiency

MANUFACTURER

BRAND

OUR CODE

THICKENING AGENT

LUBRICATION BASE

DROP PT. ºC

CONSISTENCY

OPERATING TEMP. ºC

MIL STANDARD

SHELL OIL CO. ALVANIA NO.1 AV2 LITHIUM MINERAL 182 272 -25 TO +120 MIL-18709
ALVANIA NO.3 AV3 LITHIUM MINERAL 183 233 -20 TO +135 -
ALVANIA RA AVS LITHIUM MINERAL 183 252 -40 TO +130 -
AERO SHELL GREASE NO. 7* AG7 MICROGEL DIESTER >260 288 -73 TO +149 MIL-G-23827B
AERO SHELL GREASE NO.15A AG5 FLUOROTELOMER SILICONE >260 280 -73 TO +260 -
ESSO ANDOK B AKB SODIUM MINERAL 260 285 -40 TO +120 MIL-G-18709A
ANDOK C* AKC SODIUM MINERAL >260 205 -20 TO +120 -
ANDOK 260 AK2 SODIUM MINERAL 200 260 -30 TO +150 MIL-G-3545B
BEACON 325* B32 LITHIUM DIESTER 193 280 -60 TO +120 MIL-G-3278A
KYODO YUSHI MALTEMP PS NO.2* PS2 LITHIUM DIESTER, MINERAL 190 275 -55 TO +130 -
MALTEMP SRL* NS7 LITHIUM ESTER 191 245 -40 TO +150 -
KLUBER LUB. STABURAGS NBU12 N12 BARIUM MINERAL 220 270 -34 TO +150 -
BARRIERTA L55/2 L55 FLUOROTELOMER FLUORINATED - 280 -35 TO +220 -
BARRIERTA EL IEL FLUOROTELOMER FLUORINATED - 280 -50 TO +180 -
BARRIERTA IMI/V IMI FLUOROTELOMER FLUORINATED - 280 -50 TO +220 -
ISOFLEX NBU15 NB5 BARIUM DIESTER, MINERAL 200 280 -40 TO +130 -
ISOFLEX TOPAS NB52 NB2 BARIUM SYNTHETIC HYDROCARBON 240 280 -60 TO +170 -
ISOFLEX SUPER LDS18 SL8 LITHIUM DIESTER 190 280 -60 TO +130 MIL-G-7118A
ISOFLEX LDS18 SPECIAL A L8A LITHIUM DIESTER 190 280 -60 TO _130 MIL-G-23827A
DOW CORNING MOLYCOTE 33M M3M LITHIUM SILICONE 210 260 -70 TO +180 -
MOLYCOTE 44M M4M LITHIUM SILICONE 204 260 -40 TO +200 -
MOLYCOTE 55M D5M LITHIUM SILICONE, ESTER - - - MIL-L-4343B
MOLYCOTE BR2 PLUS BR2 LITHIUM MINERAL - 280 -30 TO +150 -
MOLYCOTE FS1292 F19 FLUOROTELOMER FLUOROSILICONE >232 310 -40 TO +200 -
MOLYCOTE FS3451 F35 FLUOROTELOMER FLUOROSILICONE >260 285 -40 TO +230 -
MOBIL OIL CO. MOBIL GREASE NO. 28 MG2 BENTONITE SYNTHETIC HYDROCARBON >260 280 -62 TO +204 MIL-G-81322C
CALTEX CHEVRON SRI-2 SRL UREA MINERAL - - -30 TO +175  
DUPONT, E.I. KRYTOX 240AC K24 FLUOROTELOMER FLUORINATED - 282 -35 TO +288 MIL-G-27617A
NIHON OIL CO. MULTINOCUREA MNU UREA MINERAL >260 290 -20 TO +175 -
SHINETSU SILICONE SILICOLUBE G40M G40 LITHIUM SILICONE 210 260 -30 TO +200 -

* Typical Standard Lubricants - as shipped from factory. Custom lubricants - are typically a factory order.

TEMPERATURE CONVERSION: °F - (1.8 X °C) + 32

 

 

ABEC Tolerances/ISO Ratings

 

Precision ball bearings are manufactured to standards established by the Annular Bearing Engineers Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). These standards have been accepted by the American National Standards Institute (ANSI) and conform essentially to the standards set by the International Standards Organization (ISO).

 

IMPORTANT NOTE - The ABEC and ISO bearing standards are primarily concerned with bearing tolerances. While tolerance is an important factor in the performance of a bearing, there are many other factors that also affect the suitability of a bearing to its application. ABEC and ISO standards do not cover: radial play, raceway curvature, surface finish, material, ball complement, number, size or precision level, retainer type, lubrication, torque, cleanliness at assembly, packaging and other factors that may be essential to the desired bearing performance.

 

ABEC/ISO TOLERANCE CHART

Inner Ring Tolerances - Inches (mm)

 

TYPE

OD SIZE

ABEC1

ABEC 3

ABEC 5

ABEC 7

ISO Normal

ISO P6

ISO P5

ISO P4

Mean Bore Tolerance

ALL

0 to .709

0 to -.0003

0 to -.0002

0 to -.0002

0 to -.0002

(0 to 18)

(0 to -.008)

(0 to -.005)

(0 to -.005)

(O to -.005)

2 PT Out of Roundness

ALL

0 to .709

NS

NS

0.0001

0.0001

(0 to 18)

(0.003)

(0.003)

Bore Taper

ALL

0 to .709

NS

NS

0.0001

0.0001

(0 to 18)

(0.003)

(0.003)

Radial Runout

ALL

0 to .709

0.0003

0.0002

0.00015

0.0001

(0 to 18)

(0.008)

(0.005)

(0.004)

(0.003)

Face Runout With Bore

ALL

0 to .709

NS

NS

0.0003

0.0001

(0 to 18)

(0.008)

(0.003)

Face Runout

ALL

0 to .709

NS

NS

0.0003

0.0001

(0 to 18)

(0.008)

(0.003)

Width Variation

ALL

0 to .709

NS

NS

0.0002

0.0001

(0 to 18)

(0.005)

(0.003)

Ring Width Toerance

ALL

0 to 1.1811

0 to -.005

0 to -.005

0 to -.001

0 to -.001

(0 to 30)

(0 to -.125)

(0 to -.125)

(0 to -.025)

(0 to -.025)

 

ABEC/ISO TOLERANCE CHART

Inner Ring Tolerances - Inches (mm)

  TYPE OD SIZE ABEC 1 ABEC 3 ABEC 5 ABEC 7
ISO Normal ISO P6 ISO P5 ISO P4
MEAN OD TOLERANCE ALL 0 to .709 +0 to -.0003 +0 to -.0003 +0 to -.0002 +0 to -.0002
(0 to 18) (+0 to -.008) (+0 to -.008) (+0 to -.005) (+0 to -.005)
.709 to 1.1811 +0 to -.0004 +0 to -.0003 +0 to -.0002 +0 to -.0002
(18 to 30) (+0 to -.010) (+0 to -.008) (+0 to -.005) (+0 to -.005)
MAX OD TOLERANCE LIMITS OPEN 0 to .709 +.0001 to -.0004 +.0001 to -.0004 +0 to -.0002 +0 to -.0002
  (0 to 18) (+.003 to -.010) (+.003 to -.010) (+0 to -.005) (+0 to -.005)
  .709 to 1.1811 +.0001 to -.0005 +.0001 to -.0004 +0 to -.0002 +0 to -.0002
  (18 to 30) (+.025 to -.010) (+.025 to -.010) (+0 to -.005) (+0 to -.005)
  0 to .709 +.0002 to -.0005 +.0002 to -.0005 +.00004 to .00024 +.00004 to .00024
SHIELDED

(0 to 18)

(+.005 to -.012) (+.005 to -.012) (+.001 to -.006) (+.001 to -.006)
  .709 to 1.1811 +.0002 to -.0006 +.0002 to -.0005 +.00004 to .00024 +.00004 to .00024
  (18 to 30) (+.005 to -.015) (+.005 to -.012) (+.001 to -.006) (+.001 to -.006)
OD 2 PT OUT OF ROUNDNESS OPEN 0 to .709 NS NS 0.0001 0.0001
  (0 to 18) - - (0.0025) (0.0025)
  .709 to 1.1811 - - 0.0001 0.0001
  (18 to 30) NS NS (0.0025) (0.0025)
SHIELDED 0 to 1.1811 - - - -
  (0 to 30) NS NS 0.0002 0.0002
  - - - (0.005) (0.005)
OD TAPER OPEN 0 to 1.1811 NS NS 0.0001 0.0001
  (0 to 30) - - (0.0025) (0.0025)
  0 to 1.1811 NS NS - -
SHIELDED (0 to 30) - - 0.0002 0.0002
  - - - (0.005) (0.005)
RADIAL RUNOUT ALL 0 to 1.1811 0.0006 0.0004 0.0002 0.00015
(0 to 30) (0.015) (0.01) (0.005) (0.004)
OD RUNOUT WITH FACE ALL 0 to .709 NS NS 0.0003 0.00015

(0 to 18)

NS NS (0.008) (0.004)
FACE RUNOUT STRAIGHT 0 to 1.1811 - - 0.0003 0.0002
  (0 to 30) - - (0.008) (0.005)
    NS NS - -
FLANGED 0 to -1.1811 - - 0.0003 0.0003
  (0 to 30) NS NS (0.008) (0.008)
WIDTH VARIATION ALL 0 to 1.1811 - - 0 to -.002 0 to -.0001
(0 to 30) NS NS (0 to -.005) (0 to -.003)
FLANGE WIDTH TOLERANCE   0 to 1.1811 0 to -.002 0 to -.002 0 to -.002 0 to -.002
(0 to 30) (0 to -.050) (0 to -.050) (0 to -.050) (0 to -.050)
FLANGE DIAMETER TOLERANCE   0 to 1.1811 +.005 to .002 +.005 to .002 0 to -.001 0 to -.001
(0 to 30) (+.125 to -.050) (+.125 to -.050) (0 to -.025) (0 to -.025)

 

 

Internal Clearance

Internal clearance is the play between outer ring, inner ring and rolling element. Generally, the amount of up and down movement of the outer ring with respect to the fixed inner ring is called the radial internal clearance and its right and left movement the axial internal clearance.

 

Bearing internal clearance in operation is an important factor that has a significant influence on other factors such as noise, vibration, heat and fatigue life. Radial ball bearings are usually classified by their internal radial clearance.

 

When measuring the internal clearance, the bearing is subjected to a standard load in order to ensure full contact between all bearing components. Under such a load, the measured value is larger than the actual value stated for radial clearance; this is due to elastic deformation. The differance is compensated by the factors given in the tables below.
 

RADIAL INTERNAL CLEARANCE OF SMALL AND MINIATURE BEARINGS
CLEARANCE MARK MC1 MC2 MC3 MC4 MC5 MC6
CLEARANCE max 0 3 5 8 13 20
min 5 8 10 13 20 28
NOTE: 1) STANDARD CLEARANCE IS MC3. 2) FOR MEASURING CLEARANCE, OFFSET BY COMPENSATION FACTOR LISTED BELOW. 3) Unit um
 
CLEARANCE MARK MC1 MC2 MC3 MC4 MC5 MC6
COMPENSATION FACTOR 1 1 1 1 2 2
NOTE: MEASURING LOAD IS AS FOLLOWS: MINIATURE BEARINGS 2.5N (0.25kgf), SMALL BEARINGS 4.4N (0.45kgf), Unit um
 
RADIAL INTERNAL CLEARANCE OF STANDARD RADIAL BALL BEARINGS
NOMINAL BORE
DIAMETER
d(mm)
CLEARANCE
C2 C0 C3 C4 C5
OVER INCL MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX
10   0 7 2 13 8 23 14 29 20 37
10 18 0 9 3 18 11 25 18 33 25 45
18 24 0 10 5 20 13 28 20 36 28 48
 
24 30 1 11 5 20 13 28 23 41 30 53
30 40 1 11 6 20 15 33 28 46 40 64
40 50 1 11 6 23 18 36 30 51 45 73
NOTE: 1. FOR MEASURING CLEARANCE, OFFSET BY COMPENSATION FACTOR LISTED BELOW. , Unit um
 
BORE DIAMETER OF NOMINAL BEARING d(mm) MEASURING LOAD COMPENSATION FACTOR
OVER INCL N(kgf) C2 C0 C3 C4 C5
10(INCLUDED) 18 24.5 (2.6) 3~4 4 4 4 4
18 50 49 (5) 4~5 5 6 6 6
NOTE: Unit um
 
RELATIONSHIP BETWEEN RADIAL INTERNAL AND AXIAL INTERNAL CLEARANCE
The axial internal clearance is established from the ball diameter, outer and inner ring raceway radius and the radial internal clearance. Usually it is about 10 times the value of the internal radial clearance. Selection of a small internal radial clearance or an extra large interference fit in order to reduce the internal axial clearance after mounting is not recommended.
 
SELECTION OF BEARING CLEARANCE
Theoretically, maximum bearing life is with very slight preload. However, even a slight increase in this theoretical preload can have a considerably detrimental effect on the bearing life. Positive clearance should therefore be selected. MC3 is usually used for miniature or small bearings, standard clearance for general bearings and the clearance for thin section bearings should never be greater than "standard".
Operating Condition Clearance
Clearance fit for inner and outer ring. Low axial load. No axial load carrying requirement. Select bearing with reduced radial clearance. Lower vibration and noise. Low speeds.  MC1,MC2,C2
Lower frictional torque. Standard axial load. Average axial load carrying requirements. Slight interference fit for inner ring. Clearance fit for outer ring. Average/low speeds. MC3,MC4,CN(C0)
Extremely low frictional torque. High axial load. High axial load carrying requirements. Heavy interfence fit to support high loads or shock loads. Large temperature gradient from inner ring to outer ring. High degree of shaft deflection. MC5,MC6,C3,C4,C5

 

 

Maximum Permissable Bearing Speed

Each bearing type has its own limiting speed. The theoretical speed that bearings can run at safely, even if heat generation by internal friction occurs, is called the maximum permissible speed. The permissible speed is related to bearing type, type of cage, lubricant type, load and cooling conditions to which the bearing is subjected.

For contact rubber seals (2RS type), the permissible speeds are limited by the peripheral velocity of the seal lip. Normally, this is approximately 50 - 60% of that of non-contact rubber seals. If light contact rubber seals are required, this must be stipulated with the order. If high loads occur, the permissible speed values must be reduced and the following supplementary factors applied, except under standard operating conditions (Cr/P<12, Fa/Fr>0.2)
 

Compensation for maximum permissable speed dependent on load ratio.

Compensation for maximum permissable speed under combined axial and radial load

 

COMPENSATION FOR MAXIMUM PERMISSIBLE SPEED DEPENDENT ON LOAD RATIO
Cr/P

5

6

7

8

9

10

11

12

COMPENSATION FACTOR

0.72

0.79

0.85

0.90

0.93

0.96

0.98

1.00

 

COMPENSATION FOR MAX PERMISSIBLE SPEED UNDER COMBINED AXIAL & RADIAL LOAD
Fa/Fr 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00
COMPENSATION FACTOR 1.00 0.95 0.93 0.91 0.89 0.88 0.87 0.86

If the bearing operates at over 70% of the permissible speed value, a lubricant for high speed should be selected. The values for the permissible speed are for applications with horizontal shafts and with appropriate lubrication. With vertical shafts, only 80% of the maximum speed speed value should be used. This is necessary due to the reduced cage guidance and reduced lubricant retention in this type of application.

 

 

Bearing Usage

NOTES ON SELECTING BEARINGS

  • The efficiency of thin type bearings can be greatly affected by the precision of the shaft and housing seats. The accuracy of the surrounding structure must be such that it will not adversely affect the operation of the bearing. If you have any questions, in particular regarding the 670 and 680 series, please contact us.
  • In applications with steel crown type cages (w type), where high acceleration, heavy loads, shock loads or vertical shafts occur, or where oil is the only lubricant, please contact us.
  • Selection of fitting clearance and grease type requires a careful consideration of rotating speed. load conditions and temperature in order to prevent premature bearing failure.
  • Full complement ball bearings are suitable for low speed and heavy radial load conditions. There is a danger of balls being pushed out of the bearing through the filling slot, even under light axial load. For this reason, full complement bearings are not suitable for supporting axial loads.

 

NOTES ON HANDLING BEARINGS

  • The actual assembly area should be kept free from dust as any contamination has a detrimental effect on the operation and life of roller bearings. If there is any doubt concerning the cleanliness of the bearing, it can be washed with a suitable agent and then relubricated.
  • When fitting bearings, the fitting forces must not be transmitted via the rolling elements. If it is necessary to heat the bearing to facilitate fitting, the temperature should not exceed +120° C.
  • After assembly, the bearing should be rotated to check its correct operation. If the bearing does not appear to be functioning correctly, it should be re-examined to establish the cause of the malfunction.
  • It is not advisable to mix oils and greases as this will affect the efficiency of the bearing.
  • Bearings must be stored in a clean environment with stable temperatures. Bearings should be handled with care to avoid the possibility of corrosion and rusting.
  • Lint-free cloth must be used to wipe shaft and housing seats to avoid the ingress of contaminants into the bearing.

BEARING USAGE

Problem Cause Remedy
Noise High pitched metalic noise
  • Poor lubrication
  • Improve lubrication
  • Clearance too small
  • Correct clearance
  • Poor fitting
  • Investigate mounting method and seating
  • Excesive load
  • Examine shaft and housing tolerances for closing effect
Low pitched metallic noise
  • Brinelled raceway surface
  • Avoid shock loads
Regular Noise
  • Rust and damage
  • Check and replace seals and relubricate
  • Flaking of raceway surface
  • Improve lubrication and check fitting, clearance and fixing method
Iregular noise
  • Ingress of foreign matter
  • Check and replace seals and relubricate
  • Excessive clearance
  • Correct clearance
  • Damage and flaking of rolling element
  • Reduce loads and/or clearance
Variable noise
  • Variable clearence due
    to temperature changes
  • check fits taking housing material and temperature into consideration
  • Damage to raceway
  • Improve lubrication and check fitting, clearance and fixing method
Heavy vibration 

 
  • Flaking of raceway and rolling element
  • Improve lubrication and check fitting, clearance and fixing method
  • Ingress of foreign matter
  • Check and replace seals and relubricate
  • Excessive clearance
  • Correct clearance
  • Poor location
  • Ensure abutment face and fitting diamater are perpendicular
Excessive heat generation
  • Clearance too small
  • Correct clearance
  • Poor location
  • Ensure abutment face and fitting diameter are perpendicular
  • Excessive load
  • Examine shaft and housing tolerances for closing effect
  • Poor lubrication
  • Improve lubrication
  • Creep
  • Maintain recommended shaft and housing fits
Lubrication failure
  • Too much grease
  • Use correct lubricant quantity
  • Ingress of foreign matter
  • Check and replace seals and relubricate

 

 

Damage/Cause/Remedy

Problem Damage Cause Remedy
High pitched metallic noise
  • Poor lubrication
  • Improve lubrication
  • Clearance too small
  • Correct clearance
  • Poor fitting
  • Investigate mounting seating & method
  • Excessive load
  • Examine shaft and housing tolrances for closing effect
Low pitched metallic noise
  • Brinelled raceway surface
  • Avoid shock loads
Regular noise
  • Rust and damage
  • Check and replace seals and relubricate
  • Flaking of raceway surface
  • Improve lubrication and check fitting
Irregular noise
  • Ingress of foriegn matter
  • Check and replace seals and relubricate
  • Excessive clearance
  • Correct clearance
  • Damage and flaking of rolling element
  • Reduce loads and/or clearance
Variable noise
  • Variable clearance due to temperature changes
  • Check fits taking housing material and temperature into consideration
  • Damage to raceways
  • Improve lubrication and check fitting
Heavy Vibration
  • Flaking of raceway and rolling element
  • Improve lubrication and check fitting
  • Ingress of foriegn matters
  • Check and replace seals and relubricate
  • Excessive clearance
  • Correct clearance
  • Poor location
  • Ensure abutment face and fitting diameter are perpendicular
Excessive Heat Generation
  • Clearance too small
  • Correct Clearance
  • Poor Location

Ensure abutment face and fitting diameter are perpendicular

  • Excessive load
  • Examine shaft and housing tolerance for closing effect
  • Poor lubrication
  • Improve lubrication
  • Creep
  • Maintain recommended shaft and housing fits
Lubrication Failure
  • Too much grease
  • Use correct lubricant quantity
  • Ingress of foreign matter
  • Check and replace seals, relubricate
Flaking

 
  • Flaking on one side of entire raceway
  • Excessive axial load by poor fitting
    or linear expansion
  • Use clearance fit on non- locating bearing outer ring
  • Flaking at rolling element pitch
    on raceways
  • Raceways brinelled during fitting 
  • Careful fitting
  • Corrosion during down time
  • Apply corrosion protective
  • Premature flaking of raceway and 
    rolling element surfaces
  • Excessive load
  • Correct clearance
  • Clearance too small
  • Poor lubrication
  • Use correct lubricant quantity
  • Poor fitting
  • Check fitting
  • Corrosion
  • Apply corrosion protective
  • Flaking across the raceway
  • Poor fitting and eccentricity
  • Fitting and centering with care
  • Shaft deflection
  • Use bearing with larger internal clearance
  • Geometric inaccuracy of shaft and housing
  • Shaft and abutments to be square
  • Flaking around araceway
  • Poor housing accuracy
  • Check geometric accuracy of housing bore
Indentations


 
  • Indentations on raceway at 
    rolling element pitch
  • Shocks loads during fitting or poor handling
  • Handling with care
  • Excessive static load
  • Check static load
  • Over-rolling
  • Ingress of foreign matter
  • Ensure cleanliness of components and integrityof seals
Pick-up
  • Discoloration of raceway and
    rolling element surface
  • Excessive load
  • Check fitting
  • Clearance too small
  • Correct clearance
  • Softening of surfaces
  • Poor lubrication
  • Use correct lubricant quantity
  • Poor fitting
  • Check fitting method
Electrical 
erosion
  • Raceway eroded at regular intervals
  • Arching due to bearing conducting electricity
  • Earth or insulate the bearing
Fracture
  • Raceway surface fracture
  • Excessive shock loads
  • Correct loading
  • High interference fit
  • Proper fitting
  • Increase of flaking and softening
  • Ensure correct geometry of shaft and housing
  • welding of inner ring to shaft
  • Ensure correct geometry of shaft and housing
  • Corner fillet radii to large
  • Correct fillet radii
  • Rolling element fracture
  • Excessive shocks loads
  • Correct loading
  • Excessive internal clearance
  • Check fiting and clearance
  • Cage fracture
  • Tilting moments
  • Fit with care
  • High speed impulse and high acceleration
  • Ensure uniform rotation
  • Incorrect lubrication
  • Check lubricant and lubrication method
  • Ingress of foreign matter in bearing
  • Improve sealing
Skidding
  • Scoring of raceway and rolling element surfaces
  • Hard grease
  • Use soft grease
  • High start up acceleration
  • Controlled acceleration
Abrasion
  • Extreme abrasion of raceway, rolling element and cage
  • Ingress of foreign matter
  • Improve Sealing
  • Corrosion
  • Poor lubrication
  • Improve lubrication
  • Creep
  • Loose fit
  • Correct tolerances and fitting
  • Incorrectly fixed
  • Correct fixing
  • Fretting corrosion
  • Small movement between surfaces
  • Increase interference fit
  • False brinelling
  • Vibration in non-rotating bearing
  • Insulate bearing from vibration
  • Small oscillations in applications
  • Use oil as lubricant, Apply preload
Corrosion
  • Rust inside bearing
  • Poor storage
  • Careful storage and handling
  • Condensation
  • Rust on fitting surface
  • Fretting
  • Increase interference fit
  • Fluctuating load
  • Use oil as lubricant
  • Corrosion
  • Ingress of acid, alkali or gas
  • Check sealing
  • Chemical reaction with lubricant
  • Use correct lubricant