Training Course on Bearings
PM Department
Trainer’s
1- Muhammad Kashif – PM Manager2- Rao Shahbaz – Reliability Engineer
Bearings are an essential component of almost all machinery. A bearing supports and guides a rotating or oscillating shaft, pivot or wheel with a minimum of friction.
The purpose of a bearing is to reduce the friction between the moving parts.
The reduction of friction can be accomplished by using material that will easily slide over each other or by the use of a lubricating oil.
Important factors while selecting bearings are:
1.Load.
2.Speed.
3.Axial Displacement.
A- Rolling Contact Bearings :load is transferred through rolling elements such as
balls, straight and tapered cylinders and spherical rollers.
B- Journal (Sleeve) Bearings:load is transferred through a thin film of lubricant
(oil).
4. The rolling elements keep the outer and inner rings separated and transmit the load from one ring to the other. The various rolling element shapes give each bearing a number of unique characteristics.
2. The outer ring is mounted in the housing and in most cases it does not rotate. There is a raceway on the inside surface of the outer ring. The shape of the raceway is determined by the rolling elements.
Bearing Parts:1. Seals are essential for a long and reliable life of the bearing. They protect the bearing from contamination and keep the lubricant inside the bearing. A bearing is pre-greased if sealed or shielded on both sides.
3. The cage is to prevent immediate contact between the rolling elements (minimize friction and heat generation). To guide the rolling elements. To provide space for the lubricant. To retain the rolling elements when bearings of separable design are mounted or dismounted.
5. The inner ring is mounted on the shaft of the machine and is in most cases a rotating part. The bore can be cylindrical or tapered. There is a raceway on the outside surface of the inner ring. The shape of the raceway is determined by the rolling elements.
1. 2. 3. 4. 5. 1.
A- Rolling Contact Bearings
Classifications:
1- Radial.
2- Thrust.
3- Tapered.
A- Rolling Contact Bearings
Support only radial loads.
Classifications:1- Radial
A- Rolling Contact Bearings
Support only axial loads.
A- Rolling Contact BearingsClassifications:2- Thrust
Support combinations of thrust and radial loads.
A- Rolling Contact BearingsClassifications:3- Tapered
a. Deep groove (Conrad) bearing.b. Angular contact bearings (AC).c. Four point ball bearing.d. Self aligning ball bearing.e. Thrust ball bearingf. Filling notch ball bearing or maximum capacity bearing.g. Spindle bearing.
1. Ball Bearings ( Point Load).
A- Rolling Contact BearingsTypes of Rolling Contact Bearings
3. Linear Bearings.4. Miscellaneous Bearings.
a. Cylindrical bearings.b. Needle bearings.c. Tapered bearings.d. Barrel bearings.e. Spherical bearings.
2. Roller Bearings ( Line Load-Higher Capacity Than BB).
A- Rolling Contact BearingsTypes of Rolling Contact Bearings
Thrust ball bearing Thrust angular contact ball bearing
Thrust cylindrical roller bearing
Thrust spherical roller bearing
Ball Bearings
Roller Bearings
Deep groove ball bearing
Angular contact ball bearingSingle row douple row
Four point ball bearing
Self aligning ball bearing
Cylindrical roller bearing
Tapered roller bearing
Barrel roller bearing
Spherical roller bearing
Thrust Bearings
A- Rolling Contact Bearings
Load capacity is limited by the number of balls
Primarily designed to support radial loads
There are further two type available in this type named as:• Single Row Deep Groove Ball Bearing• Double Row Deep Groove Ball Bearing
A- Rolling Contact Bearings1- Ball Bearingsa. Deep Groove (Conrad) Bearing
Radial load: good
Axial load: good
Alignment: dependent on the load, between 2‘ and 16‘
Limiting speed: high to very high
A- Rolling Contact Bearings1- Ball Bearingsa. Deep Groove (Conrad) Bearing
Series: 60, 62, 63, 64,
160, 161, 618, 622, 623
Suffixes:
M Solid Brass Cage
.2RS, .2RSR Two Rubber Seals
.2Z, .2ZR Two Steel Shields
A- Rolling Contact Bearings1- Ball Bearingsa. Deep Groove (Conrad) Bearing
The centerline of contact between the balls and the raceway is at an angle to the plane perpendicular to the axis of rotation.
Used for high radial and thrust load applicationsThere are further two type available in this type named as:
I. Single Row II. Double Row
A- Rolling Contact Bearings1- Ball Bearingsb. Angular Contact Bearings (AC)
Radial load: good
Axial load: high in one direction
Alignment: very small
Limiting speed: high, spindle bearing very high
Angular contact ball bearingA- Rolling Contact Bearings1- Ball Bearingsb. Angular Contact Bearings (AC)
Series: 72B, 73B
Suffixes:
MP solid window brass cage
TVP solid window polyamide cage
UA universal design, pairs have a small axial clearance
UO universal design, pairs have a zero clearance
A- Rolling Contact Bearings1- Ball Bearingsb. Angular Contact Bearings (AC)
Radial load: good
Axial load: high in both direction
Alignment: very small
Limiting speed: high
A- Rolling Contact Bearings1- Ball Bearingsb. Angular Contact Bearings-Double Row
Series: 32, 33 Contact Angle 35°
32B, 33B Contact Angle 25°
33DA Contact Angle 45°
Suffixes:
M Machined Brass Cage
TVP Solid Window Polyamide Cage
.2RSR Two Rubber Seals
.2ZR Two Steel Shields
A- Rolling Contact Bearings1- Ball Bearingsb. Angular Contact Bearings-Double Row
Radial load: small
Axial load: high in both directions
Alignment: very small
Limiting speed: medium to high
A- Rolling Contact Bearings1- Ball Bearingsc. Four Point Ball Bearing
z
Series: QJ2, QJ3
Suffixes:
MPA Machined window-type brass cage, outer ring guided
N2 Two retaining grooves
TVP Solid window-type cage of glass-fibre reinforced polyamide
A- Rolling Contact Bearings1- Ball Bearingsc. Four Point Ball Bearing
Radial load: small
Axial load: small
Alignment: approx. 4°, sealed types up to 1,5°
Limiting speed: high
A- Rolling Contact Bearings1- Ball Bearingsd. Self Aligning Ball Bearing
Series: 10, 12, 13, 22, 23, 112
Suffixes:
K Tapered Bore
M Machined Brass Cage
.2RS Two Rubber Seals
TV Solid Cage of glass-fibre reinforced polyamide
A- Rolling Contact Bearings1- Ball Bearingsd. Self Aligning Ball Bearing
THANK YOUEND OF DAY ONE
Radial load: none
Axial load: high
Alignment: none
Limiting speed: medium
A- Rolling Contact Bearings1- Ball Bearingse. Thrust Ball Bearing
Radial load: none
Axial load: high in both directions
Alignment: none
Limiting speed: medium
A- Rolling Contact Bearings1- Ball Bearingse. Thrust Ball Bearing-double row
Series: 511, 512, 513, 514, 532, 533, 522, 523, 542, 543
Suffixes:
M machined brass cage
MP machined window-type brass cage
FP machined window-type steel cage
A- Rolling Contact Bearings1- Ball Bearingse. Thrust Ball Bearing
Bearings have the same basic radial construction as Conrad type. However, a filling notch (loading groove) permits more balls to be used.
Radial load capacity is 20 – 40% higher than Conrad type
Thrust load capacity drops to 20% (2 directions) of radial load capacity.
Notch
A- Rolling Contact Bearings1- Ball Bearingsf. Filling notch or maximum capacity Ball Bearing
Series: B719, B70, B72
HSS719, HSS70
Suffixes:
C Contact angle 15°
E Contact angle 25°
P4S Tolerance class P4S
T Solid window-type cage of textile laminated phenolic resin
UL Universal design, pairs are lightly preloaded
A- Rolling Contact Bearings1- Ball Bearingsg. Spindle Bearing
Roller bearings have higher
load capacity than ball
bearings, load is transmitted
through line contact instead
of point contact.
A- Rolling Contact Bearings2- Roller Bearingsa. Cylindrical Roller Bearing
Radial load: very high
Axial load: none, small when bearings have lips
Alignment: very small, between 1‘ and 4‘
Limiting speed: high to very high
Remark: seperable, well suited for floating bearings
A- Rolling Contact Bearings2- Roller Bearingsa. Cylindrical Roller Bearing
Series: NU2E, NU3E, NU10, NU19, NU22E, NU23E
Suffixes:
E Maximum capacity design
M, M1 Machined brass cage
TVP2 Solid window-type cage of glass-fibre reinforced polyamide
A- Rolling Contact Bearings2- Roller Bearingsa. Cylindrical Roller Bearing
a
NUP N NJ u. HJ NU u. HJNU NJ
A- Rolling Contact Bearings2- Roller Bearingsa. Cylindrical Roller Bearing
Radial load: very high
Axial load: none, lips can carry small thrust loads
Alignment: very low
Limiting speed: high to very high
A- Rolling Contact Bearings2- Roller Bearingsa1. Cylindrical Roller Bearing-double Row
Series: NN30, NNU49
Suffixes:
S Lubricating groove
K Tapered bore
M Machined brass cage
SP Tolerance class SP, bearing clearance C1NA
A- Rolling Contact Bearings2- Roller Bearingsa1. Cylindrical Roller Bearing-double Row
Radial load: none
Axial load: very high
Alignment: none
Limiting speed: low
A- Rolling Contact Bearings2- Roller Bearingsa2. Cylindrical Thrust Roller Bearing
Series: 811, 812
Suffixes:
LPB Machined window-type cage of light metal, shaft guided
MB Machined brass cage, shaft guided
MPB Machined window-type brass cage, shaft guided
TVPB, Machined window-type of TVPB1glass-fibre reinforced polyamide, shaft guided
A- Rolling Contact Bearings2- Roller Bearingsa2. Cylindrical Thrust Roller Bearing
A- Rolling Contact Bearings2- Roller Bearingsb. Needle Roller Bearing
Needle roller bearings are roller bearings with cylindrical rollers which are thin and long in relation to their diameter. They are referred to as needle rollers. In spite of their low cross section the bearings have a high load carrying capacity and are thus extremely suitable for bearing arrangements where radial space is limited.
Designed to withstand high radial loads, high thrust loads, and combined loads at moderate to high speeds. They can also withstand repeated shock loads.
A- Rolling Contact Bearings2- Roller Bearingsc. Taper Roller Bearing
Radial load: very high
Axial load: high in one direction, matched in both directions
Alignment: small 1‘ to 4‘
Limiting speed: medium to high
Tapered roller bearingA- Rolling Contact Bearings2- Roller Bearingsc. Taper Roller Bearing
Series: 302, 303, 313, 320, 322, 323, 329, 330, 331, 332
Suffixes:
A Changed internal design
A...N11CA Axial clearance in µm, two X arranged bearings with spacers between the cups
B Increased contact angle
X Outer dimensions adapted to international standards
Tapered roller bearingA- Rolling Contact Bearings2- Roller Bearingsc. Taper Roller Bearing
Radial load: very high
Axial load: small
Alignment: very high, up to 4° (self Aliging)
Limiting speed: low to medium
Barrel roller bearingA- Rolling Contact Bearings2- Roller Bearingsd. Barrel Roller Bearing
Barrel roller bearing
Series: 202, 203
Suffixes:
K Tapered bore
MB Machined brass cage, inner ring guided
T Solid window-type cage of glass-fibre reinforced polyamide
A- Rolling Contact Bearings2- Roller Bearingsd. Barrel Roller Bearing
Roller Bearings
Bearing design uses barrel shaped rollers. Spherical roller bearings combine very high radial load capacity with modest thrust load capacity and excellent tolerance to misalignment.
A- Rolling Contact Bearings2- Roller Bearingse. Spherical Roller Bearing
Radial load: very high
Axial load: good
Alignment: good, between 0,5° to 2°
Limiting speed: low to medium
Spherical roller bearingA- Rolling Contact Bearings2- Roller Bearingse. Spherical Roller Bearing
Spherical roller bearing
Series: 213, 222, 223, 230, 231, 232, 233, 239, 240, 241
Suffixes:
A, B Changed internal design
E Maximum capacity design
K Tapered bore
M Machined brass cage
MA Machined brass cage, outer ring guided
MB Machined brass cage, inner ring guided
TVPB Solid window-type cage of glass-fibre reinforced polyamide, inner ring guided
A- Rolling Contact Bearings2- Roller Bearingse. Spherical Roller Bearing
Radial load: medium
Axial load: very high
Alignment: high, 1,5° to 2,5°
Limiting speed: medium to
high, with oil lubrication
Thrust spherical roller bearingA- Rolling Contact Bearings2- Roller Bearingse1. Spherical Thrust Roller Bearing
Thrust spherical roller bearing
Series: 292E, 293E, 294E
Suffixes:
E Maximum capacity design
MB Machined brass cage, shaft guided
A- Rolling Contact Bearings2- Roller Bearingse1. Spherical Thrust Roller Bearing
Linear BearingsA- Rolling Contact Bearings3- Linear Bearings
Load runners (idler-rollers)
Roller bearing cam follower
Flanged V-Grooved
Spherical rod end
A- Rolling Contact Bearings4- Miscellaneous Bearings
Bearings
Airframe control bearings – designed to meet the specific needs of the airframe industry, meets military and national standards.
Designed to carry heavy static load and will also handle oscillation or slow rotation.
Track rollers, withstand heavy rolling loads.
A- Rolling Contact Bearings4- Miscellaneous Bearings
• Ball bearings are the less expensive choice in the smaller sizes and under
lighter loads, while roller bearings are less expensive for larger sizes and
heavier loads.
• Roller bearings are more satisfactory under shock or impact loading than
ball bearings.
• Ball-thrust bearings are for pure thrust loading only.
• At high speeds, a deep-groove or angular-contact ball bearing usually will
be a better choice, even for pure thrust loads.
• Self-aligning ball bearings and cylindrical roller bearings have very low
friction coefficients.
A- Rolling Contact BearingsSummary:
The amount of initial radial clearance required in bearing depends mainly on the fits and temperature gradient inside the bearing. Operational radial clearance is almost always less than initial clearance.(Clearance indication normally uses as suffix.Normally terms for clearance are:C1: radial clearance less than C2C2: radial clearance less than NormalCN: Normal radial clearanceC3: radial clearance greater than NormalC4: radial clearance greater than C3C5: radial clearance greater than C4
A- Rolling Contact BearingsBearing Clearance:
A- Rolling Contact BearingsNomenclature Of Bearing:
A- Rolling Contact BearingsNomenclature Of Bearing:
A- Rolling Contact BearingsNomenclature Of Bearing:
A- Rolling Contact BearingsNomenclature Of Bearing:
in beside box.
A- Rolling Contact BearingsNomenclature Of Bearing:
AR- Ball or roller and cage assembly OR- Outer ring of radial bearing
GS Housing washer of cylindrical roller thrust bearing R Separable bearing without removable inner
or outer ring
IR- Inner ring of radial bearing W Deep groove ball bearing of stainless steel
K Cylindrical roller and cage thrust assembly WFDeep groove ball bearing of stainless steel with external flange on outer ring
K-
Inner ring with roller and cage assembly (cone) or outer ring (cup) of a taper roller bearing belonging to an ABMA standard series and generally having inch dimensions ( being phase out)
WS Shaft washer of a cylindrical roller thrust bearing
L Removable inner or outer ring of a separable bearing
A- Rolling Contact BearingsNomenclature Of Bearing:Bearing Prefixes:
C Deviating or modified internal design with same boundary dimensions. 2RS2 RS1 contact seal on both sides of bearing.
CCTwo bearings arranged back to back or face-to-face will have an axial internal clearance larger than normal clearance(CB) before mounting.
RZSheet steel reinforced low-friction seal of acrylonitrile-butadiene rubber(NBR) on one side of bearing.
CL3 Inch taper roller bearing with tolerance to class 3 according to ANSI/ABMA Standard 19.2:1994 2RZ RZ low-friction seal on both sides of bearing.
EDeviating or modified internal design with same boundary dimensions; usually indicates reinforced rolling element .
K Tapered bore, taper 1:12.
2RS RS contact seal on both sides of bearing. W Without annular groove and lubrication holes in outer ring.
RS1 Sheet steel reinforced contact seal of acrylonitrile-butadiene rubber(NBR) on one side of bearing. W33 Annular grooves and three lubrication holes in outer
ring.
2RS1 RS1 contact seal on both sides of bearing. W33X Annular grooves and six lubrication holes in outer ring.
RS1Z NBR on one side and one shield on the other side of bearing. Z Shield of pressed sheet steel on one side of bearing.
RS2 Sheet steel reinforced contact seal of fluoro rubber (FKM)on one side of bearing. 2Z Z shield on both side of bearing.
A- Rolling Contact BearingsNomenclature Of Bearing:Bearing Suffixes:
Load is transferred through a lubricant in sliding contact.
B- Journal (Sleeve) Bearings
I. BronzeII. White MetalIII. Cast Iron
IV. SinteredV. PlasticVI. Composite
These are the simplest types of bearings. They consist of a plain hole in a part in which a shaft rotates. This bearing is only effective with moderate speeds & loads. Available material types for journal bearings are:
B- Journal (Sleeve) Bearings
• Low starting and operating friction.• Can support combined radial and thrust loads.• Less sensitive to interruptions of lubrication.• No self-excited instabilities.• Good low-temperature starting.• Can seal lubricant within bearing and “lifetime-
lubricate”.• Typically require less space in axial direction.
Roller Bearing Vs. Sliding BearingAdvantages of Roller Bearing
• May eventually fail from fatigue.• Require more space in radial direction.• Poor damping ability.• Higher noise level.• More severe alignment requirements.• Higher cost.• Higher friction (than hydrodynamic sliding).
Roller Bearing Vs. Sliding BearingDisadvantages of Roller Bearing
Bearing housings are an essential
requirement for safe operating and
enhancing the durability of any industrial
bearing. It is used basically to mount
bearings safely. The bearings housing
position the insert bearing and at the same
time support loads that are transferred
from the shaft through the bearing.
Bearing Housing
• Bearings housings are easy to install and remove as they are manufactured with flat mounting surfaces.
• Bearing housing helps in enhancing the overall performance of the bearings.
• Seals are attached on bearings housing which prevent dust and other contaminants from entering the housing, thereby protecting the bearings.
Bearing HousingBenefits of Bearing Housing:
Bearing HousingBenefits of Bearing Housing:• The bearings housing provides a clean
environment for the bearings to rotate freely.• It helps in increasing bearings' performance,
durability and duty cycle. Housings provide for proper lubrication.
• Additional monitoring systems can also be incorporated for hi-fi bearings housing.
• They are ideal for light as well as heavy duty applications
Types Of Bearing Housing
Plummer Block housings ease to constitute bearing units by using with self-aligning ball bearings or spherical roller bearings. Wide range of sizes and configurations allows selection of optimal housing.
Split Type One Piece Type
Types Of Bearing Housing1- Plummer Block Bearings Housing:
Flanged housings of smaller sizes are triangular and the larger sizes have a square shape. They can be used for self-aligning ball bearings and spherical roller bearings. They can be used for tapered bores on an adapter sleeve on smooth shafts.
Types Of Bearing Housing2- Flanged Bearings Housing:
They require felt seals and grease lubrication. They are made of gray cast iron. Different types of flanged ball bearings are used for mild and harsh conditions.
THD take-up housings are specially designed for belt conveyors. They can be used for:spherical roller bearings in the 230, 231, 232 and 222 series.CARB bearings in the C 30, C 31, C 32 and C 22 series.
Types Of Bearing Housing3- Take Up Bearings Housing:
The housings are designed for bearing arrangement type "Bearing on adapter sleeve and smooth shafts" with 50 to 400 mm diameter