A spherical roller thrust bearing is a

rolling-element bearing In mechanical engineering, a rolling-element bearing, also known as a rolling bearing,ISO 15 is a bearing (mechanical), bearing which carries a load by placing rolling elements (such as balls, cylinders, or cones) between two concentric, Groove ...

of thrust type that permits rotation with low

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...

, and permits angular misalignment. The bearing is designed to take radial loads, and heavy axial loads in one direction. Typically these bearings support a rotating shaft in the bore of the shaft washer that may be misaligned in respect to the housing washer. The misalignment is possible due to the spherical internal shape of the house washer.

Construction

Spherical roller thrust bearings consist of a shaft washer (for radial bearings often called "inner ring"), a housing washer (for radial bearings often called "outer ring"), asymmetrical rollers and a cage. There are also bearing units available that can take axial loads in two directions.

History

The spherical roller thrust bearing was introduced by

SKF AB SKF (, 'Swedish Ball Bearing Factory') is a Swedish bearing (mechanical), bearing and seal (mechanical), seal manufacturing company founded in Gothenburg, Sweden, in 1907. The company manufactures and supplies bearings, seals, lubrication an ...

in 1939. The design of the early bearings is similar to the design that is still in use in modern machines.

Designs

The internal design of the bearing is not standardised by ISO, so it varies between different manufacturers and different series. Some of the design parameters are: * Roller shape and dimensions * Flange design * Non-rotational notches in house washer The spherical roller thrust bearings have the highest load rating density of all thrust bearings.

Dimensions

External dimensions of spherical roller bearings are standardised by

ISO The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. Me ...

in the standard ISO 104:2015. Some common series of spherical roller bearings are: * 292 * 293 * 294

Materials

Bearing rings and rolling elements can be made of a number of different materials, but the most common is "chrome steel", a material with approximately 1.5% chrome content. Such "chrome steel" has been standardized by a number of authorities, and there are therefore a number of similar materials, such as: AISI 52100 (USA), 100CR6 (Germany), SUJ2 (Japan) and GCR15 (China). Some common materials for bearing cages:{{cite web, title=Cage materials, url=http://www.skf.com/group/products/bearings-units-housings/roller-bearings/principles/bearing-data-general/materials-for-rolling-bearings/cage-materials/index.html, publisher=SKF, accessdate=5 December 2013 *

Sheet steel Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate, ...

(stamped or laser-cut) *

Brass Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. I ...

(stamped or machined) *

Steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

(machined) The choice of material is mainly done by the manufacturing volume and method. For large-volume bearings, cages are often of stamped sheet-metal, whereas low volume series often have cages of machined brass or machined steel.

Manufacturers

Some manufacturers of ''spherical roller bearings'' are

Schaeffler Schaeffler Technologies AG & Co. KG, also known as the Schaeffler Group (''Schaeffler-Gruppe'' in German), is a German manufacturer of rolling element bearings for automotive, aerospace and industrial uses, including the FAG brand. It was fou ...

Timken Company The Timken Company is a global manufacturer of bearings and power transmission products. Timken operates from 42 countries. Company history In 1898, Henry Timken obtained a patent for an improved tapered roller bearing, and in 1899 incorpo ...

and NSK Ltd.

Applications

Spherical roller thrust bearings are used in industrial applications, where there are heavy axial loads, moderate speeds and possibly misalignment. Some common application areas are: *

Gearboxes A transmission (also called a gearbox) is a mechanical device invented by Louis Renault (who founded Renault) which uses a gear set—two or more gears working together—to change the speed, direction of rotation, or torque multiplication/r ...

Pulp and paper The pulp and paper industry comprises companies that use wood, specifically pulpwood, as raw material and produce pulp, paper, paperboard, and other cellulose-based products. Manufacturing process In the manufacturing process, pulp is introd ...

processing equipment (notably refiners) *

Marine propulsion Marine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electri ...

and

offshore drilling Offshore drilling is a mechanical process where a wellbore is drilled below the seabed. It is typically carried out in order to explore for and subsequently extract petroleum that lies in rock formations beneath the seabed. Most commonly, the ter ...

* Cranes and

swing bridge A swing bridge (or swing span bridge) is a movable bridge that can be rotated horizontally around a vertical axis. It has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravit ...

s *

Water turbine A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, t ...

s * Extruders for injection molding

References

Bearings (mechanical) Rolling-element bearings Mechanical engineering Swedish inventions