Spherical roller bearings are rolling-element bearings that permit rotation with low friction and permits angular misalignment. These bearings support a rotating shaft in the bore of the inner ring that may be misaligned in respect to the outer ring. The misalignment is possible due to the spherical internal shape of the outer ring and spherical rollers. Despite their name, spherical roller bearings are not truly spherical in shape. The rolling elements of spherical roller bearings are mainly cylindrical in shape, but have a profile that makes them appear like cylinders that have been slightly over-inflated. The spherical roller bearing was invented by engineer Arvid Palmgren his design is still in use in modern machines.
All spherical roller bearings have the same working principal. They all have outer rings that with concave (spherical) inner raceways. The inner rings similarly have convex outer raceways (or rolling elements that create a matching convex sliding surface). What separates the various types of spherical bearings is the design of their sliding surface. Some are ring-to-ring (such as spherical plain bearings and rod ends), others use rolling elements such as balls or rollers between the inner and outer rings.
Deep Groove Ball Bearings are the most popular of all bearing types due to their incredible versatility. Some characteristics may include:
Household Items: Bicycles, Skateboards, Sewing Machines, Washing Machines, Tumble Driers, Food Processors, Hair Dryers, DVD Players, Fishing Rods.
Office Equipment: Photocopiers, Fax Machines, Hard-Drives, Fans, Air-Conditioners
Industries: Electric Motors, Pumps / Compressors, Blowers, Elevators, Assembly Lines, Escalators, Medical and Dental Equipment, High-speed Machine Tooling Equipment, Paper Making Machinery, Chain Saws, Power Tools, Toy Manufacturing, Trains, Wind Turbines.
Automotive: Engines, Steering, Driveshaft and Driveline, Alternators, Gear Boxes, Transmissions, Automotive Starters and many many more.
Factors such as speed, load conditions, space availability, and accessibility requirements influence bearing selection. We at JVN Bearings provide a range of ball bearings to our customers which may include:
Miniature Ball Bearings are small bearings with balls as their rolling elements. These small bearings have an outside diameter of less than 9.525 mm. They typically have 3 digits Ex: 625 2RS These bearings are offered in various ABEC classes, in either chrome or stainless steel. Both metric and inch styles are available.
Deep Groove Radial Ball Bearings are the most popular and widely used type of bearing. They are used for heavy radial loads and lower bidirectional thrust loads. Typically employed in high-speed precision applications such as fans or motorbikes. Ex: 6301 ZZ. They can be designed with enhanced metal shields (ZZ) or rubber seals (2RS) . Multiple internal clearances, tolerance grades, and cage designs are offered to suit specific applications’ running precision and speed.
Double Row Deep Groove Ball Bearings are very suitable for bearing arrangements where the load carrying capacity of a single row bearing is inadequate. For the same bore and outside diameter, double row bearings are slightly wider than single row bearings, but have a considerably higher load carrying capacity. Ex: 4210.
Example: What does 6301ZZ C3 Z1V1 mean?
It is a Metric Medium Sized Bearing with a bore diameter of 12mm, which has a loose internal clearance and noise / vibration grade of Z1V1. The above chart gives a brief description about the nomenclature of Deep Groove Ball Bearings. For further details about how to understand bearing nomenclature please read this article.
Bearing numbers can seem very confusing and random to the average person. But there is a system to all the madness!
There are several numbering systems used in the bearing industry today. The boundary dimensions for certain series of bearings are defined in various standards, such as ABMA, JIS and ISO. (Learn more about them here.) In addition, many manufacturers have created their own numbering systems that are a combination of the bearing numbers and a series of codes that define additional specifications.
Type Code | Bearing Name |
1 | Self Aligning Ball Bearings |
2 | Spherical Ball Bearings |
3 | Taper Roller Bearings |
4 | Double Row Ball Bearings |
5 | Thrust Ball Bearings |
6 | Single Row Deep Groove Ball Bearings |
7 | Single Row Angular Contact Bearings |
N | Single Row Cylindrical Roller Bearings |
NA | Needle Roller Bearings |
The first digit of a bearing signifies the type of bearing. For Ex: In a 6208 bearing the first digit being ‘6′ is a Single Row Deep Groove Ball Bearing.
In case of Inch bearings, the bearing’s first digit will be ‘R’. After ‘R’, the size of the bearing will be given in 1/16th of an inch. For Ex: R6-2RS bearing. Here, R6 signifies, it is an inch bearing whose bore size is 6/16th of an inch or 0.375 inches.
Series Code | Toughness Description |
0 | Extra Light |
1 | Extra Light Thrust |
2 | Light |
3 | Medium |
4 | Heavy |
8 | Extra Thin Section |
9 | Very Thin Section |
The second digit of a bearing number indicates the Bearing Series which denotes the toughness / strength of the bearing. Bearing strength is the maximum stress load that the unit can “bear” or hold before the structure fails. It can be measured by Tensile Strength, Tensile Elongation, Compressive Strength, Flexural Strength, Modulus and Hardness.
Last Digits | Bore Size (04 and Up: Multiply Last Two Numbers by 5 to get bore in MM) |
00 | 10 |
01 | 12 |
02 | 15 |
03 | 17 |
04 | (x5) = 20 |
05 | (x5) = 25 |
06 | (x5) = 30 and so on. |
The third and fourth digit of a bearing number as indicated above refers to the bore size of the bearing. It is the inner diameter of the bearing and is measured in millimeters. From ’00’ to ’03’ the measurements are noted above. From ’04’ onward the bore size is equal to five times the third and forth digit of bearing’s last two numbers.
In case there is no fourth digit, then the 3rd digit indicates the bore size in mm. For Ex: In case of bearing 625 2RS, the bore size of the bearing will be 5mm.
Thus, we can identify now that in case of bearing 6207ZZ, the third and fourth digit ‘07’ means the bearing’s bore size is 35 mm.
Shield / Seal Code | Description |
Z | Single Side Metal Shield |
ZZ | Both Sides Metal Shield |
RS | Single Rubber Seal |
2RS | Both Sides Rubber Seal |
V | Single Non-Contact Seal |
VV | Double Non-Contact Seal |
DDU | Double Contact Seal |
NR | Snap Ring and Groove |
M | Brass Cage |
The letters after the bearing number indicates the presence / absence / type of shielding or sealing and any other specialties in the bearing. We can identify now that in case of bearing 6208RS, the last letters ‘RS’ means the bearing is shielded on a single side.
Internal Clearance | |
C2 | : Tight |
C0 | : Normal |
C3 | : Loose |
C4 | : Extra Loose |
Bearing internal clearance means the total distance through which one bearing ring can be moved in relation to the other in the radial direction (radial internal clearance) or in the axial direction (axial internal clearance).
In almost all applications, the initial clearance in a bearing is greater than its running clearance. The difference is mainly caused by:
Noise / Vibration Level | |
Z1V1 | : Good |
Z2V2 | : Better than Z1V1 |
Z3V3 | : Better than Z2V2 |
Z4V4 | : Best |
Bearing acoustical noise is a function of both (Internal Factors) the bearing itself and (External factors) the way in which it is used. Bearing noise is not generally influenced by ABEC precision, they are independent of precision grades. For Ex. A P6 / ABEC 3 bearing can have a rating of Z2V2 or above. Bearing Noise is affected by the manufacturers’ Internal quality standards with regard to the
External factors affecting bearing noise include:
The vibration and noise of bearings are classified as four classed as Z1,Z2,Z3 and Z4.It is measured by the instrument of S0910-1.For special requirement, it is measured by BVT-1 and classified as V1, V2, V3 and V4. The classes help consumers select bearings. For Ex: A Z3V3 bearing has an average range of 25-35 dB which is suitable for applications such as in ceiling fans. dB is a measure of volume (loudness of a sound).
Decibels | Example Source |
0 | Silence |
20 | Whispering |
50 | Relaxed Conversation |
80 | Food Processor, Lawn Mower |
110 | Rock Concert, Chainsaw |
What is a standard?
A standard is a document that specifies requirements for products, services and/or processes, laying down their required characteristics. This helps ensure the free movement of goods and encourages exports. It serves to safeguard people and goods and to improve quality in all areas of life.
How is it developed?
Standards are developed by those who have a need and an interest in using them. The broad participation of all stakeholders, a transparent development process and the consensus principle ensure the wide acceptance of a standard.
Who develops standards for bearings?
There are several bodies that are recognized throughout the world in terms of bearing standards and nomenclature. They are:
Tolerance classes for ball bearings were defined by a committee within the ABMA known as the “Annular Bearings Engineers Committee” (ABEC). These tolerances are commonly referred to as ABEC rating or grade. Tolerance classes for roller bearings are covered by the RBEC classifications contained within the same standard.
The ABEC (and RBEC) tolerance classifications specify both tolerances of size and form for the individual inner and outer rings. The critical features of the rings include the bore (or inner diameter of the inner ring), the outer diameter of the outer ring, the ring widths, and the raceways of each ring. Tolerances of the form include roundness, taper, runout, and parallelism.
There are five classes from largest to smallest tolerances: ABEC 1, ABEC 3, ABEC 5, ABEC 7, and ABEC 9. The higher ABEC classes provide better precision, efficiency, and the possibility of greater speed capabilities, but do not necessarily allow the components to spin faster. The ABEC rating does not specify many critical factors, such as load handling capabilities, ball precision, materials, material Rockwell hardness, degree of ball and raceway polishing, noise, vibration, and lubricant. Due to these factors, an ABEC 3 classified bearing could perform better than an ABEC 7 bearing. Bearings not conforming to at least ABEC 1 cannot be classified as precision bearings as their tolerances are too loose.
The scale also works as a guide for consumers to make informed decisions about the type of bearing they desire, despite not knowing factors related to materials, manufacturing, and performance.
High rated bearings are intended for precision applications like aircraft instruments or surgical equipment. Lower graded bearings are intended for the vast majority of applications such as vehicles, mechanical hobbies, skates, skateboards, fishing reels, and industrial machinery. High ABEC rated bearings allow optimal performance of critical applications requiring very high RPM and smooth operation.
Comparison of Tolerance Classifications of National Standards
Standard | Applicable Standard | Tolerance Class | Bearing Types | ||||
---|---|---|---|---|---|---|---|
American National Standards Institute (ANSI) | ANSI/ABMA Std.20 | ABEC-1 / RBEC-1 | ABEC-3 / RBEC-3 | ABEC-5 / RBEC-5 | ABEC-7 | ABEC-9 | Radial bearings (Except tapered roller bearings) |
American Bearing Manufacturer's Association (ABMA) | ANSI/ABMA Std.19.1 | Class K | Class N | Class C | Class B | Class A | Tapered roller bearings (Metric series) |
ANSI/ABMA Std.19 | Class 4 | Class 2 | Class 3 | Class 0 | Class 00 | Tapered roller bearings (Inch series) | |
Deutsches Institut fur Normung (DIN) | DIN 620 | P0 | P6 | P5 | P4 | P2 | All type |
Japanese Industrial Standard (JIS) | JIS B 1514 | Class 0,6X | Class 6 | Class 5 | Class 4 | Class 2 | All type |
ISO 492 | Normal class | Class 6 | Class 5 | Class 4 | Class 2 | Radial bearings | |
Class 6X | |||||||
International Organization for Standardization (ISO) | ISO 199 | Normal Class | Class 6 | Class 5 | Class 4 | ー | Thrust ball bearings |
ISO 578 | Class 4 | ー | Class 3 | Class 0 | Class 00 | Tapered roller bearings (Inch series) | |
ISO 1224 | ー | ー | Class 5A | Class 4A | ー | Precision instrument bearings |
Table Terminology:
Bearing Tolerances: It refers to three aspects of accuracy:
Allowable error limitations for the three areas of bearing accuracy have been internationally standardized for many years as tolerance classes. Each tolerance class specifies a group of limits for all the measures of accuracy (varying in proportion to the bearing size). The most recognized standards are compared in the table above (note that each column represents a set of equivalent classes). For the ISO, JIS, and DiN standards, bearings with standard accuracy are classified as class 0. This is then followed by class 6. From there on, decreasing class numbers denote progressively improving accuracy.
Radial Runout: Radial run-out is the variation of wall thickness in a bearing race. In technical terms, run-out is the measurement of the raceway in which the rolling element rides and how it relates to the outer ring’s outer diameter and the inner ring’s inner diameter as you rotate the bearing 360 degrees. Incorrect run-out can cause a wide variety of issues, depending on the application. For example, if you have a machine designed to create specially aligned holes in a part, incorrect run-out could affect the proper placement of the holes, meaning those holes might not match up with the mating part. In a motor application, you could face issues with vibration or noise.
Table IA
Tolerance Class ABEC-1, RBEC-1
(ISO Class Normal)
Inner Ring
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | (Tolerance values in 0.0001 inch) | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -3 | 4 | 0 | -16 | - |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -3 | 4 | 0 | -47 | -98 |
10 | 18 | 0.3937 | 0.7087 | 0 | -3 | 4 | 0 | -47 | -98 |
18 | 30 | 0.7087 | 1.1811 | 0 | -4 | 5 | 0 | -47 | -98 |
30 | 50 | 1.1811 | 1.9685 | 0 | -4.5 | 6 | 0 | -47 | -98 |
50 | 80 | 1.9685 | 3.1496 | 0 | -6 | 8 | 0 | -59 | -150 |
80 | 120 | 3.1496 | 4.7244 | 0 | -8 | 10 | 0 | -79 | -150 |
120 | 180 | 4.7244 | 7.0866 | 0 | -10 | 12 | 0 | -98 | -197 |
180 | 250 | 7.0866 | 9.8425 | 0 | -12 | 16 | 0 | -118 | -197 |
250 | 315 | 9.8425 | 12.4016 | 0 | -14 | 20 | 0 | -138 | -197 |
315 | 400 | 12.4016 | 15.7480 | 0 | -16 | 24 | 0 | -157 | -248 |
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -8 | 10 | 0 | -40 | - |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -8 | 10 | 0 | -120 | -250 |
10 | 18 | 0.3937 | 0.7087 | 0 | -8 | 10 | 0 | -120 | -250 |
18 | 30 | 0.7087 | 1.1811 | 0 | -10 | 13 | 0 | -120 | -250 |
30 | 50 | 1.1811 | 1.9685 | 0 | -12 | 15 | 0 | -120 | -250 |
50 | 80 | 1.9685 | 3.1496 | 0 | -15 | 20 | 0 | -150 | -380 |
80 | 120 | 3.1496 | 4.7244 | 0 | -20 | 25 | 0 | -200 | -380 |
120 | 180 | 4.7244 | 7.0866 | 0 | -25 | 30 | 0 | -250 | -500 |
180 | 250 | 7.0866 | 9.8425 | 0 | -30 | 40 | 0 | -300 | -500 |
250 | 315 | 9.8425 | 12.4016 | 0 | -35 | 50 | 0 | -350 | -500 |
315 | 400 | 12.4016 | 15.7480 | 0 | -40 | 60 | 0 | -400 | -630 |
Table IB
Tolerance Class ABEC-1, RBEC-1
(ISO Class Normal)
Outer Ring
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -3 | 6 | |||
6 | 18 | 0.2362 | 0.7087 | 0 | -3 | 6 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -3.5 | 6 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -4.5 | 8 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -5 | 10 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -6 | 14 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -7 | 16 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
150 | 180 | 5.9055 | 7.0866 | 0 | -10 | 18 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -12 | 20 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -14 | 24 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -16 | 28 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -18 | 31 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -20 | 39 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -30 | 47 | |||
800 | 1000 | 31.4961 | 39.3701 | 0 | -39 | 55 |
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | Tolerance values in micrometers | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -8 | 15 | |||
6 | 18 | 0.2362 | 0.7087 | 0 | -8 | 15 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -9 | 15 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -11 | 20 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -13 | 25 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -15 | 35 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
120 | 150 | 4.7244 | 5.9055 | 0 | -18 | 40 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -25 | 45 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -30 | 50 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -35 | 60 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -40 | 70 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -45 | 80 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -50 | 100 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -75 | 120 | |||
800 | 1000 | 31.4961 | 39.3701 | 0 | -100 | 140 |
Table II A
Tolerance Class ABEC-3, RBEC-3
(ISO Class 6)
Inner Ring
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -3 | 2 | 0 | -16 | - |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -3 | 2.5 | 0 | -47 | -98 |
10 | 18 | 0.3937 | 0.7087 | 0 | -3 | 3 | 0 | -47 | -98 |
18 | 30 | 0.7087 | 1.1811 | 0 | -3 | 3 | 0 | -47 | -98 |
30 | 50 | 1.1811 | 1.9685 | 0 | -4 | 4 | 0 | -47 | -98 |
50 | 80 | 1.9685 | 3.1496 | 0 | -4.5 | 4 | 0 | -59 | -150 |
80 | 120 | 3.1496 | 4.7244 | 0 | -6 | 5 | 0 | -79 | -150 |
120 | 180 | 4.7244 | 7.0866 | 0 | -7 | 7 | 0 | -98 | -197 |
180 | 250 | 7.0866 | 9.8425 | 0 | -8.5 | 8 | 0 | -118 | -197 |
250 | 315 | 9.8425 | 12.4016 | 0 | -10 | 10 | 0 | -138 | -197 |
315 | 400 | 12.4016 | 15.7480 | 0 | -16 | 24 | 0 | -157 | -248 |
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -7 | 5 | 0 | -40 | - |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -7 | 6 | 0 | -120 | -250 |
10 | 18 | 0.3937 | 0.7087 | 0 | -7 | 7 | 0 | -120 | -250 |
18 | 30 | 0.7087 | 1.1811 | 0 | -8 | 8 | 0 | -120 | -250 |
30 | 50 | 1.1811 | 1.9685 | 0 | -10 | 10 | 0 | -120 | -250 |
50 | 80 | 1.9685 | 3.1496 | 0 | -12 | 10 | 0 | -150 | -380 |
80 | 120 | 3.1496 | 4.7244 | 0 | -15 | 13 | 0 | -200 | -380 |
120 | 180 | 4.7244 | 7.0866 | 0 | -18 | 18 | 0 | -250 | -500 |
180 | 250 | 7.0866 | 9.8425 | 0 | -22 | 20 | 0 | -300 | -500 |
250 | 315 | 9.8425 | 12.4016 | 0 | -25 | 25 | 0 | -350 | -500 |
315 | 400 | 12.4016 | 15.7480 | 0 | -30 | 30 | 0 | -400 | -630 |
Table II B
Tolerance Class ABEC-3, RBEC-3
(ISO Class 6)
Outer Ring
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -3 | 3 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
6 | 18 | 0.2362 | 0.7087 | 0 | -3 | 3 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -3 | 3.5 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -3.5 | 4 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -4.5 | 5 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -5 | 7 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -6 | 8 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -7 | 9 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -8 | 10 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -10 | 12 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -11 | 14 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -13 | 16 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -20 | 39 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -18 | 24 | |||
800 | 1000 | 31.4961 | 39.3701 | 0 | -24 | 30 |
Outer Diameter (D) | (Metric) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | Tolerance values in micrometers | ||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | single bearing | paired bearings | ||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -7 | 8 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
6 | 18 | 0.2362 | 0.7087 | 0 | -7 | 8 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -8 | 9 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -9 | 10 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -11 | 13 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -13 | 18 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -15 | 20 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -18 | 23 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -20 | 25 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -25 | 30 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -28 | 35 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -33 | 40 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -38 | 50 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -45 | 60 | |||
800 | 1000 | 31.4961 | 39.3701 | 0 | -60 | 75 |
Table III A
Tolerance Class ABEC-5, RBEC-5
(ISO Class 5)
Inner Ring
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -2 | 1.5 | 0 | -16 | -98 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -2 | 1.5 | 0 | -16 | -98 |
10 | 18 | 0.3937 | 0.7087 | 0 | -2 | 1.5 | 0 | -31 | -98 |
18 | 30 | 0.7087 | 1.1811 | 0 | -2.5 | 1.5 | 0 | -47 | -98 |
30 | 50 | 1.1811 | 1.9685 | 0 | -3 | 2 | 0 | -47 | -98 |
50 | 80 | 1.9685 | 3.1496 | 0 | -3.5 | 2 | 0 | -59 | -98 |
80 | 120 | 3.1496 | 4.7244 | 0 | -4 | 2.55 | 0 | -79 | -150 |
120 | 180 | 4.7244 | 7.0866 | 0 | -5 | 3 | 0 | -98 | -150 |
180 | 250 | 7.0866 | 9.8425 | 0 | -6 | 4 | 0 | -118 | -197 |
250 | 315 | 9.8425 | 12.4016 | 0 | -7 | 5 | 0 | -138 | -197 |
315 | 400 | 12.4016 | 15.7480 | 0 | -9 | 6 | 0 | -157 | -248 |
Bore Diameter (d) | Metric | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | Tolerance values in micrometers | ||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -5 | 4 | 0 | -40 | -250 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -5 | 4 | 0 | -40 | -250 |
10 | 18 | 0.3937 | 0.7087 | 0 | -5 | 4 | 0 | -80 | -250 |
18 | 30 | 0.7087 | 1.1811 | 0 | -6 | 4 | 0 | -120 | -250 |
30 | 50 | 1.1811 | 1.9685 | 0 | -8 | 5 | 0 | -120 | -250 |
50 | 80 | 1.9685 | 3.1496 | 0 | -9 | 5 | 0 | -150 | -250 |
80 | 120 | 3.1496 | 4.7244 | 0 | -10 | 6 | 0 | -200 | -380 |
120 | 180 | 4.7244 | 7.0866 | 0 | -13 | 8 | 0 | -250 | -380 |
180 | 250 | 7.0866 | 9.8425 | 0 | -15 | 10 | 0 | -300 | -500 |
250 | 315 | 9.8425 | 12.4016 | 0 | -18 | 13 | 0 | -350 | -500 |
315 | 400 | 12.4016 | 15.7480 | 0 | -23 | 15 | 0 | -400 | -630 |
Table III B
Tolerance Class ABEC-5, RBEC-5
(ISO Class 5)
Outer Ring
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -2 | 2 | |||
6 | 18 | 0.2362 | 0.7087 | 0 | -2 | 2 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -2.5 | 2.5 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -3 | 3 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -3.5 | 3 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -4 | 4 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
120 | 150 | 4.7244 | 5.9055 | 0 | -4.5 | 4.5 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -5 | 5 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -6 | 6 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -7 | 7 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -8 | 8 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -9 | 9 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -11 | 10 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -14 | 12 |
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -5 | 5 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
6 | 18 | 0.2362 | 0.7087 | 0 | -5 | 5 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -6 | 6 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -6 | 6 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -9 | 8 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -10 | 10 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -11 | 11 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -13 | 13 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -15 | 15 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -18 | 18 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -20 | 20 | |||
400 | 500 | 15.7480 | 19.6850 | 0 | -23 | 23 | |||
500 | 630 | 19.6850 | 24.8031 | 0 | -28 | 25 | |||
630 | 800 | 24.8031 | 31.4961 | 0 | -35 | 30 |
Table IV A
Tolerance Class ABEC-7, RBEC-7
(ISO Class 4)
Inner Ring
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -1.5 | 1 | 0 | -16 | -98 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -1.5 | 1 | 0 | -16 | -98 |
10 | 18 | 0.3937 | 0.7087 | 0 | -1.5 | 1 | 0 | -31 | -98 |
18 | 30 | 0.7087 | 1.1811 | 0 | -2 | 1 | 0 | -47 | -98 |
30 | 50 | 1.1811 | 1.9685 | 0 | -2.5 | 1.5 | 0 | -47 | -98 |
50 | 80 | 1.9685 | 3.1496 | 0 | -3 | 1.5 | 0 | -59 | -98 |
80 | 120 | 3.1496 | 4.7244 | 0 | -3 | 2 | 0 | -79 | -150 |
120 | 180 | 4.7244 | 7.0866 | 0 | -4 | 2.5 | 0 | -98 | -150 |
180 | 250 | 7.0866 | 9.8425 | 0 | -4.5 | 3 | 0 | -118 | -197 |
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | Tolerance values in 0.0001 inch | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -4 | 2.5 | 0 | -40 | -250 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -4 | 2.5 | 0 | -40 | -250 |
10 | 18 | 0.3937 | 0.7087 | 0 | -4 | 2.5 | 0 | -80 | -250 |
18 | 30 | 0.7087 | 1.1811 | 0 | -5 | 3 | 0 | -120 | -250 |
30 | 50 | 1.1811 | 1.9685 | 0 | -6 | 4 | 0 | -120 | -250 |
50 | 80 | 1.9685 | 3.1496 | 0 | -7 | 4 | 0 | -150 | -250 |
80 | 120 | 3.1496 | 4.7244 | 0 | -8 | 5 | 0 | -200 | -380 |
120 | 180 | 4.7244 | 7.0866 | 0 | -10 | 6 | 0 | -250 | -380 |
180 | 250 | 7.0866 | 9.8425 | 0 | -12 | 8 | 0 | -300 | -500 |
Table IV B
Tolerance Class ABEC-7, RBEC-7
(ISO Class 4)
Outer Ring
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | Tolerance values in 0.0001 inch | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -1.5 | 1 | |||
6 | 18 | 0.2362 | 0.7087 | 0 | -1.5 | 1 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -2 | 1.5 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -2.5 | 2 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -3 | 2 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -3 | 2.5 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
120 | 150 | 4.7244 | 5.9055 | 0 | -3.5 | 3 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -4 | 3 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -4.5 | 4 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -5 | 4.5 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -6 | 5 |
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -4 | 3 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
6 | 18 | 0.2362 | 0.7087 | 0 | -4 | 3 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -5 | 4 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -6 | 5 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -7 | 5 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -8 | 6 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -9 | 7 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -10 | 8 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -11 | 10 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -13 | 11 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -15 | 13 |
Table V A
Tolerance Class ABEC-9, RBEC-9
(ISO Class 2)
Inner Ring
Bore Diameter (d) | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | Tolerance values in 0.0001 inch | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -1 | 0.5 | 0 | -16 | -98 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -1 | 0.5 | 0 | -16 | -98 |
10 | 18 | 0.3937 | 0.7087 | 0 | -1 | 0.5 | 0 | -31 | -98 |
18 | 30 | 0.7087 | 1.1811 | 0 | -1 | 1 | 0 | -47 | -98 |
30 | 50 | 1.1811 | 1.9685 | 0 | -1 | 1 | 0 | -47 | -98 |
50 | 80 | 1.9685 | 3.1496 | 0 | -1.5 | 1 | 0 | -59 | -98 |
80 | 120 | 3.1496 | 4.7244 | 0 | -2 | 1 | 0 | -79 | -150 |
120 | 150 | 4.7244 | 5.9055 | 0 | -3 | 1 | 0 | -98 | -150 |
150 | 180 | 5.9055 | 7.0866 | 0 | -3 | 2 | 0 | -98 | -150 |
180 | 250 | 7.0866 | 9.8425 | 0 | -3 | 2 | 0 | -118 | -197 |
Bore Diameter (d) | Metric | Bore Tolerance (Δdmp) | Radial Runout (Kia) | Width Tolerance (ΔBS) | Tolerance values in micrometers | ||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
0.6 | 2.5 | 0.0236 | 0.0984 | 0 | -2.5 | 1.5 | 0 | -40 | -250 |
2.5 | 10 | 0.0984 | 0.3937 | 0 | -2.5 | 1.5 | 0 | -40 | -250 |
10 | 18 | 0.3937 | 0.7087 | 0 | -2.5 | 1.5 | 0 | -80 | -250 |
18 | 30 | 0.7087 | 1.1811 | 0 | -2.5 | 2.5 | 0 | -120 | -250 |
30 | 50 | 1.1811 | 1.9685 | 0 | -2.5 | 2.5 | 0 | -120 | -250 |
50 | 80 | 1.9685 | 3.1496 | 0 | -4 | 2.5 | 0 | -150 | -250 |
80 | 120 | 3.1496 | 4.7244 | 0 | -5 | 2.5 | 0 | -200 | -380 |
120 | 150 | 4.7244 | 5.9055 | 0 | -7 | 2.5 | 0 | -250 | -380 |
150 | 180 | 5.9055 | 7.0866 | 0 | -7 | 5 | 0 | -250 | -380 |
180 | 250 | 7.0866 | 9.8425 | 0 | -8 | 5 | 0 | -300 | -500 |
Table V B
Tolerance Class ABEC-9, RBEC-9
(ISO Class 2)
Outer Ring
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | ||||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -1 | 0.5 | |||
6 | 18 | 0.2362 | 0.7087 | 0 | -1 | 0.5 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -1 | 0.5 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -1.5 | 1 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -1.5 | 1.5 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
80 | 120 | 3.1496 | 4.7244 | 0 | -2 | 2 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -2 | 2 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -3 | 2 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -3 | 3 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -3 | 3 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -4 | 3 |
Outer Diameter (D) | Outer Dia. Tolerance (Δdmp) | Radial Runout (Kea) | Width Tolerance (ΔBS) | Tolerance values in 0.0001 inch | |||||
---|---|---|---|---|---|---|---|---|---|
mm | inch | all | single bearing | paired bearings | |||||
over | incl. | over | incl. | high | low | max. | high | low | |
2.5 | 6 | 0.0984 | 0.2362 | 0 | -2.5 | 1.5 | Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing | ||
6 | 18 | 0.2362 | 0.7087 | 0 | -2.5 | 1.5 | |||
18 | 30 | 0.7087 | 1.1811 | 0 | -4 | 2.5 | |||
30 | 50 | 1.1811 | 1.9685 | 0 | -4 | 2.5 | |||
50 | 80 | 1.9685 | 3.1496 | 0 | -4 | 4 | |||
80 | 120 | 3.1496 | 4.7244 | 0 | -5 | 5 | |||
120 | 150 | 4.7244 | 5.9055 | 0 | -5 | 5 | |||
150 | 180 | 5.9055 | 7.0866 | 0 | -7 | 5 | |||
180 | 250 | 7.0866 | 9.8425 | 0 | -8 | 7 | |||
250 | 315 | 9.8425 | 12.4016 | 0 | -8 | 7 | |||
315 | 400 | 12.4016 | 15.7480 | 0 | -10 | 8 |
There are various types of bearings, each used for specific purposes and designed to carry specific types of loads, i.e., radial loads, thrust loads, or some combination of the two.
1) Ball Bearings
Ball bearings are extremely common because they can handle both radial and thrust loads, but can only handle a small amount of weight. They are further classified into:
Application of Ball Bearings:
Household Items: Bicycles, Skateboards, Sewing Machines, Washing Machines, Tumble Driers, Food Processors, Hair Dryers, DVD Players, Fishing Rods.
Office Equipment: Photocopiers, Fax Machines, Hard-Drives, Fans, Air-Conditioners
Industries: Elevators, Assembly Lines, Escalators, Medical and Dental Equipment, High-speed Machine Tooling Equipment, Paper Making Machinery, Chain Saws, Power Tools, Pumps / Compressors. Toy Manufacturing, Trains, Wind Turbines.
Automotive: Engines, Steering, Driveshaft and Driveline, Electric Motors, Gear Boxes, Transmissions
2. Tapered Roller Bearings
Tapered angles allow the bearings to efficiently control a combination of radial and thrust loads. The steeper the outer ring angle, the greater ability the bearing has to handle thrust loads. To provide a true rolling motion of the rollers on the raceways, the extensions of the raceways and the tapered surfaces of the rollers come together at a common point, the apex, on the axis of rotation.
Applications: Agriculture, construction and mining equipment, sports robot combat, axle systems, gearbox, engine motors and reducers, propeller shaft, railroad axle-box, differential, wind turbines, etc.
3. Spherical Roller Bearings
A spherical roller bearing is a rolling-element bearing that permits rotation with low friction and permits angular misalignment. Typically, these bearings support a rotating shaft in the bore of the inner ring that may be misaligned with respect to the outer ring. The misalignment is possible due to the spherical internal shape of the outer ring and spherical rollers. Despite what their name may imply, spherical roller bearings are not truly spherical in shape. The rolling elements of spherical roller bearings are mainly cylindrical in shape but have a profile that makes them appear like cylinders that have been slightly over-inflated.
Applications: Gearboxes, wind turbines, continuous casting machines, material handling, pumps, mechanical fans and blowers, mining and construction equipment, pulp and paper processing equipment, marine propulsion and offshore drilling, off-road vehicles.
4. Cylindrical Roller Bearings
Cylindrical Roller Bearings are designed to carry heavy loads—the primary rolling element is a cylinder, which means the load is distributed over a larger area, enabling the bearing to handle larger amounts of weight. This structure, however, means the bearing can handle primarily radial loads, but is not suited to thrust loads. For applications where space is an issue, a needle bearing can be used. Needle bearings work with small diameter cylinders, so they are easier to fit in smaller applications.
Applications: Mining, petroleum production, power generation, power transmission, cement processing, aggregate crushing, and metal recycling, Briquetting machines, rubber mixing equipment, rolling mills, rotary dryers, or pulp and paper machinery, construction equipment, crushers, electric motors, blowers and fans, gears and drives, plastics machinery, machine tools and traction motors and pumps.
5. Needle Roller Bearings
A needle roller bearing is a special type of roller bearing which uses long, thin cylindrical rollers resembling needles. Ordinary roller bearings rollers are only slightly longer than their diameter, but needle bearings typically have rollers that are at least four times longer than their diameter.
Applications: Needle bearings are heavily used in automobile components such as rocker arm pivots, pumps, gearboxes, automotive power transmission systems, two and four stroke engines, planetary gear sets and air compressors.
6. Slewing Bearings
A slewing bearing or slewing ring is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slow-oscillating load, often a horizontal platform such as a conventional crane, a swing yarder, or the wind-facing platform of a horizontal-axis windmill. (To “slew” means to turn without change of place.) Slewing bearings are often made with gear teeth integral with the inner or outer race, used to drive the platform relative to the base.
Applications:
Construction: Cranes for Bulk/Scrap handling, shocks vibration ,Handling container Rubber tyre – gantry crane & Reach Stackers, Concrete Pumps and Mixers,
Medical: Radiotherapy applications, pharmaceutical industry for all production steps, mixing, filling, cleaning, etc.
Water Treatment, Offshore Mining, Forest Industries, Radar Military, Manlifts in Fire trucks, etc.
7. Thrust Ball Bearings
A thrust bearing permit rotation between parts, but they are designed to support a high axial load while doing this (parallel to the shaft). Higher speed applications require oil lubrication. Generally, they are composed of two washers (raceways) which may be grooved the rolling balls elements which are typically caged. As opposed to roller thrust bearings, ball thrust bearings can generally operate at higher speeds but at lower loads.
Roller thrust bearings, much like ball thrust bearings, handle thrust loads. The difference, however, lies in the amount of weight the bearing can handle: roller thrust bearings can support significantly larger amounts of thrust load, and are therefore found in car transmissions, where they are used to support helical gears. Gear support, in general, is a common application for roller thrust bearings.
Applications: Thrust bearings are commonly used in automotive, marine, and aerospace applications. They are also used in the main and tail rotor blade grips of RC (radio controlled) helicopters, forward gears in modern car gearboxes, radio antenna masts to reduce the load on an antenna rotator, in an automobile the clutch “throw out” bearing, sometimes called the clutch release bearing.
8. Plain Bearings
Plain bearings are the simplest type of bearing and are composed of just the bearing surface with no rolling elements. They have a high load-carrying capacity, are generally the least expensive and, depending on the materials, have much longer lives than other types.
Applications: Turbomachines, such as power plant steam turbines, compressors operating in critical pipeline applications, ship propeller shafts, etc.
9. Specialized Bearings
There are, of course, several kinds of bearings that are manufactured for specific applications, such as magnetic bearings and giant roller bearings.
What are Bearings?
A bearing is a machine element that constrains relative motion and is used to reduce friction between moving parts of a machine to obtain the desired motion. For example, A load of a rotating fan is supported by a bearing while reducing noise and vibration and restricting the movement to a radial axis.
The main functions of bearings are:
How do Bearings Work?
Components / Parts of a Standard Bearing
The standard essential components of a bearing are as follows:
The word “bearing” incorporates the meaning of “to bear,” in the sense of “to support,” and “to carry a burden.” This refers to the fact that bearings support and carry the burden of different types of moving elements. Bearings reduce friction and allow a controlled and efficient transmission of power