Differences between ball, roller and tapered roller bearings

A bearing's main function is to reduce friction between different contact surfaces when there is a rotary movement. The bearing is incorporated as the intermediate element between the fixed parts or elements and those that are rotating. These devices have a high precision and low friction which allows high rotations, but with reduced noise, heat and power consumption.

Regardless of the type of object in which the bearing is located, its general structure is always the same. There is a set of balls or cylinders within a ring, which allows a force (load) to be applied to the ball or cylinder.

Ball bearings typically contain multiple balls that can support radial and axial loads. With a roller bearing, the principle is the same, but with cylindrical or tapered rollers instead of balls. The idea behind both types of bearing is to reduce friction and allow smooth movement.

Ball bearings

In ball bearings, a radial load means that the bearing will rotate or roll under tension, while the movement of an axial load depends on the force and angle.

Characteristics / Advantages of ball bearings:

• Reducedcost;
• Has one point of contact;
• More effective when the force applied to the bearing is perpendicular to its axis of rotation;
• Requires less maintenance relative to roller bearings.

Roller bearings

The bearing in roller bearings reduces friction to allow rotation of heavy radial loads and limited axial loads (no thrust load).

Roller bearings are often used for heavier loads than ball bearings and as a result, roller bearings can be found in many heavy industrial equipment such as pumps, turbines and fans. Ball bearings are more common than roller bearings, especially when it comes to objects that can be found at home.

Features / Advantages of Cylindrical Roller Bearings:

• Can withstand highloads;
• Contains a contact;
• Designed for long service life;
• Can withstand higher speeds when enclosed;
• High robustness.

Tappered roller bearings

Tapered roller bearings support radial and axial loads, which makes them much more versatile. This type of bearing can support very high loads and angular misalignment between the inner and outer rings. They are suitable for vehicle transmissions and machine spindles.

In a tapered roller bearing, the rings and rollers have a tapered shape to support axial and radial loads simultaneously. The ratio of the loads depends on the angle of the shafts between the roller and the bearing. The greater the angle, the greater the axial load that can be supported. The contact angle for most tapered roller bearings ranges between 10 and 16 degrees. For greater thrust load capacity, a contact angle of 30 degrees is used.

Tapered roller bearings are mounted in pairs as they handle radial loads better than a single row of roller bearings for heavy duty applications, two or four rows of tapered rollers are combined into a single unit in large bearings.

Main features:

• Can withstand high loads;
• High rigidity;
• Low friction;
• Design for long service life;
• High degree of reliability.