Types of Bearings

Deep-Groove Ball Bearings

The most common bearing of all — the default choice for general-purpose rotation. Balls run in deep grooves in both rings, giving low, almost point-contact friction.

Construction

Single row of balls in deep raceway grooves, held by a cage.

Loads

Radial and moderate axial load in both directions.

Speed

Very high; low friction, low noise.

Typical Uses

Electric motors, pumps, gearboxes, fans, appliances — almost anywhere.

Variants & Designations

6xxx series; available open, shielded (Z / ZZ) or sealed (RS / 2RS).

Angular-Contact Ball Bearings

Designed to carry a defined axial load in one direction as well as radial load, by setting the ball contact at an angle across the bearing.

Construction

Single row of balls with a contact angle (commonly 15°, 25° or 40°); raceway shoulders are higher on one side.

Loads

Combined radial and one-direction axial; the larger the contact angle, the more axial capacity.

Speed

Very high; widely used in precision spindles.

Typical Uses

Machine-tool spindles, pumps, gearboxes — wherever axial location and high speed are both needed.

Variants & Designations

7xxx (single row), often mounted in pairs (back-to-back, face-to-face or tandem) and preloaded; double-row types also exist.

Self-Aligning Ball Bearings

Built to keep running smoothly even when the shaft is slightly misaligned or deflects under load.

Construction

Two rows of balls sharing a common spherical raceway in the outer ring, so the inner ring and balls can swivel.

Loads

Moderate radial, low axial.

Speed

High.

Typical Uses

Long or multi-bearing shafts prone to misalignment, textile and woodworking machinery, fans.

Variants & Designations

12xx / 13xx (and wider 22xx / 23xx); available on tapered bores with adapter sleeves.

Cylindrical Roller Bearings

Use line contact instead of point contact, so they carry much heavier radial loads than ball bearings of the same size.

Construction

One row of cylindrical rollers; flanges (ribs) on one or both rings determine whether the shaft is guided axially.

Loads

High radial. Most designs allow the shaft to move axially, which suits floating (non-locating) positions and thermal expansion; some designs (NJ, NUP) also locate the shaft.

Speed

High.

Typical Uses

Large electric motors, gearboxes, axleboxes, rolling-mill stands.

Variants & Designations

N, NU, NJ, NUP, NF (the letters describe the flange arrangement); full-complement versions carry very heavy loads at lower speed.

Tapered Roller Bearings

Carry heavy combined loads — radial and one-direction axial together — using tapered rollers whose contact lines meet at a common point on the axis.

Construction

Tapered rollers between tapered raceways; the cup (outer ring) separates from the cone (inner ring with rollers).

Loads

Heavy radial and heavy one-direction axial.

Speed

Moderate.

Typical Uses

Automotive wheel hubs, axles, gearboxes, heavy machinery; four-row versions support rolling-mill roll necks.

Variants & Designations

Mounted in opposing pairs with clearance or preload set at assembly; metric 3xxxx series (e.g. 30205) and inch series.

Spherical Roller Bearings

Combine very high load capacity with self-alignment — the heavy-duty choice for tough, misaligning conditions.

Construction

Two rows of barrel-shaped rollers running on a common spherical raceway in the outer ring, so the bearing self-aligns.

Loads

Very high radial and moderate axial in both directions.

Speed

Moderate.

Typical Uses

Vibrating screens, crushers, continuous casters, paper mills, fans and heavy industrial drives.

Variants & Designations

222xx / 223xx etc.; available on tapered bores with adapter sleeves.

Thrust Bearings

Made specifically to carry axial (thrust) loads rather than radial ones.

Construction

Washers (races) with balls or rollers between them. Thrust ball bearings handle lighter axial loads; cylindrical and spherical roller thrust bearings handle heavier ones. Single- or double-direction.

Loads

High to very high axial; little or no radial capacity.

Speed

Lower than radial bearings.

Typical Uses

Crane hooks, vertical pump and turntable shafts, gearbox thrust take-up, swivels.

Variants & Designations

5xxxx thrust ball; spherical roller thrust for combined heavy axial with some radial.

Fluid-Film (Plain / Journal) Bearings

The oldest bearing principle — no rolling elements at all. A film of lubricant separates the shaft from the bearing surface, giving quiet, vibration-free running and, when the film is maintained, almost unlimited life.

Construction

A bush, sleeve or set of pads around the shaft. The film may be self-generating with speed (hydrodynamic) or supplied under pressure (hydrostatic). Oil-film "Morgoil"-type bearings support rolling-mill back-up rolls.

Loads

Very high; excellent at absorbing shock and damping vibration.

Speed

From very slow heavy shafts to very high-speed turbines.

Typical Uses

Steam and gas turbines, large compressors, engine crankshafts, rolling-mill back-up rolls, and large slow-moving heavy shafts.

Materials

White metal (babbitt), bronze or polymer bearing surfaces.

Taper Roller Bearings:
Taper roller bearings consists of two main units, a cup and a cone. The cup is on the outer race whereas the cone consists of inner race, the separator and compliment of taper rollers. The taper rollers are guided by the high load on the inner race. The taper roller bearings are manufactured with interchangeable cups and cone on the shaft separately. These bearings are capable of carrying both the radial and axial loads and permit fine adjustment for end play. Greater care is required to ensure the proper alignment of bearings and maintenance of proper axial clearance is essential to avoid bearing failure. Due to more development in the design of the taper roller bearings, these are also available with 2 rows and 4 rows.

Needle Roller Bearings:
Needle roller bearings comprise of special form of cylindrical roller bearings in which the rollers are of a very small diameter and comparatively long therefore they have the advantage of a very small difference bet These bearings are detachable and suitable for carrying only radial loads. Various designs of needle roller bearings are available and depending upon the designs of the bearing assembly. Needle roller bearings may be used either without an inner race or outer race or even without any races merely using a set of needle rollers. In all these cases the shaft or the housing should be strictly of the same qualities as of the bearings races( Hardness, Accuracy and finish); Needle roller bearings are found applicable where space is restricted and mostly where the units are oscillating.

Thrust Ball Bearings:
Thrust bearings are available mainly in two types, such as single and double thrust. Single thrust bearings consists of two rings and a set of balls in a retainer. Double thrust bearings consist of one rotating ring in the middle with two ball tracks, two sets of balls in a retainer and two stationary rings. Tracks of balls are ground in such a way that the forces between the balls and tracks are parallel to the axis of the shaft. Single thrust bearings are designed for carrying load in one direction only. Whereas double thrust can take in both directions. But these bearings can never carry any radial loads. On account of the centrifugal forces on the balls , these bearings have a limitation in the speed of outer operation.

Spherical Roller Thrust Bearings:
This type of bearing is characterized by its high axial load carrying capacity. It can also absorb considerable radial loads because the direction of contact is inclined to the axis of the shaft. The track of the housing washer is spherical, and the rolling bodies are barrel shaped. This makes the bearing self-aligning and therefore insensitive to misalignment.

Power Transmission Unit:
This unit consists of bearing with pillow block. The bearing is having self color for the grip which cannot loosen and the spherical outer race provides self- alignment in any direction. The pillow block is having oil hole on the top for re-lubrification and bolt hole at the base to fix standard bolt. Complete Unit can attach with machinery frames on a straight shaft with slip fit. The pre lubricated bearings with the felt seals enable the unit to install even in dusty environment.

Shafer Bearings for Fertilizers and Chemical Unit:
Shafer bearing in a block is a special unit consisting of double row taper bearing with concave rollers. This is designed for heavy thrust as well as radial loads with with shocks. The micro lock washer on an extended inner ring provides fast adjoinment and resists vibration. Due to special "Z" Housing seals dirt stays out and grease stays in even under severest conditions.

Single Row Radial Wide Type Bearings:
Wide type bearings are similar to single row deep groove ball bearings, having standard bore and outside diameter, but thickness is same as double row bearings of corresponding sizes in inch dimensions. Extra thickness in this bearing provides layer support area for shaft and housing contact and also space for pre packed lubricant which has sufficient place for grease expansion under agitation. Due to wide play seal these bearings are suitable for electric motors where it simplifies housing design. Bearings are also available in mechanic seals.

Plastic Bearings
Plastic Bearings are Lightweight, Low Friction, Lube Free, and Can be Run In Liquids. Bearing Rings Can Be Molded To Integrate With Customer Applications. Specials Made In Low/High Quantities. Services Include Prototyping, Pilot Runs & Custom Designs. Many different types of plastics have properties which make them suitable for bearing applications, the most commonly used are phenolics, acetals, UHMWPE, and nylon. The major limitations involved in the use of plastics have to do with high temperatures and possible cold flow under heavy loads.