What is BALL BEARING ?
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
Ball bearings use balls to separate two “races,” or bearing rings, to reduce surface contact and friction across moving planes. The rotation of the balls causes a reduced coefficient of friction when compared with flat surfaces rubbing against each other. Because there is little surface contact between the balls and races, ball bearings typically have a lower load capacity for their size than other rolling-element bearings.
STRUCTURE Of BALL BEARING
Rolling bearings (bearings hereinafter) normally comprise bearing rings, rolling elements, and a cage.
Rolling elements are arranged between inner and outer rings with a cage, which retains the rolling elements in correct relative position, so they do not touch one another.
With this structure, a smooth rolling motion is realized during operation.
Bearings are classified as follows, by the number of rows of rolling elements: single- row, double-row, or multi-row (triple- or four- row) bearings.
TYPE Of BALL BEARING WE DEAL IN
(1) DEEP GROOVE BALL BEARINGS
Deep groove ball bearings are the most widely used bearing type and are particularly versatile. They have low friction and are optimized for low noise and low vibration which enables high rotational speeds. They accommodate radial and axial loads in both directions, are easy to mount and require less maintenance than other bearing types.
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DESIGNS AND VARIANTS
1) Single Row Deep Groove Ball Bearing
2) S.S. Single Row Deep Groove Ball Bearing
3) Single Row Deep Groove Ball Bearing With Filing Slots
4) Double Row Deep Groove Ball Bearing
(2)ANGULAR CONTACT BALL BEARINGS
Angular contact ball bearings have inner and outer ring raceways that are displaced relative to each other in the direction of the bearing axis. This means that these bearings are designed to accommodate combined loads, i.e. simultaneously acting radial and axial loads.
The axial load carrying capacity of angular contact ball bearings increases as the contact angle increases. The contact angle is defined as the angle between the line joining the points of contact of the ball and the raceways in the radial plane, along which the combined load is transmitted from one raceway to another, and a line perpendicular to the bearing axis.
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DESIGNS AND VARIANTS
1) Single row angular contact ball bearings
2) Double row angular contact ball bearings
3) Four-point contact ball bearings
(3) SELF-ALIGNING BALL BEARING
Self-aligning ball bearings have two rows of balls, a commonly sphered raceway in the outer ring and two deep uninterrupted raceway grooves in the inner ring. They are available open or sealed. The bearings are insensitive to angular misalignment of the shaft relative to the housing, which can be caused, for example, by shaft deflection.
(4) THRUST BALL BEARING
Thrust ball bearings are manufactured as single direction or double direction thrust ball bearings. They are designed to accommodate axial loads only and must not be subjected to any radial load.
In addition to the bearings presented in this section, supplies thrust ball bearings for special application requirements. This assortment includes bearings with Solid Oil and NoWear coated bearings.
BALL BEARING UNIT
Because of their versatility and cost-effectiveness, ball bearing units are used in many industrial applications.
Ball bearing units consist of an insert bearing mounted in a housing. An insert bearing is a deep groove ball bearing with a sphered (convex) outside surface and an extended inner ring that includes a mechanism to lock the unit onto the shaft. The housings have a correspondingly sphered but concave bore.
TYPE OF BALL BEARING UNIT
(1) PILLOW BLOCK BALL BEARING (UCP)
Because of their versatility and cost-effectiveness, ball bearing units are used in many industrial applications.
Ball bearing units consist of an insert bearing mounted in a housing. An insert bearing is a deep groove ball bearing with a sphered (convex) outside surface and an extended inner ring that includes a mechanism to lock the unit onto the shaft. The housings have a correspondingly sphered but concave bore.
(2) Flanged type (UCF, UCFL, UCFC)
Pillow block bearings consist of a sealed single-row ball bearing with a spherical outer ring which is mounted in a housing. Because of the spherical outer surface of the bearing, shaft misalignment can be compensated for. The bearings are manufactured with a plus tolerance. This results in transition or press-fit when using shafts with h-tolerances. The shaft is secured by grub screws on the inner ring.
In normal applications, pillow block bearings are maintenance-free due to the lifetime lubrication. In difficult environmental conditions re-lubrication can be carried out over the grease nipple.
All housing dimensions are nominal dimensions for which the usual casting tolerances must be taken into consideration.
(3) Take-up type (UCT)
Take-up bearings are a type of mounted bearing primarily used for adjusting and maintaining conveyor belt tension. Take-up is the process of adjusting the length of the belt and chain to compensate for stretch, shrinkage, or wear, and to maintain proper tension. This is done with the assembly of the necessary structural and mechanical parts, including take-up bearings. The take-up bearing assembly consists of a housing that is mounted to a frame. The bearing is guided along with the frame by a slot in the bearing housing or other means. The take-up assembly contains a screw or other mechanism for adjusting its location along with the frame. A shaft connects two take-up bearings, one mounted on each side of the assembly. When a conveyor belt or chain needs to be replaced or tightened, the take-up bearing is adjusted via the screw or other mechanism to provide the appropriate amount of tension on the system.
