A spherical roller thrust bearing is a

rolling-element bearing In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, grooved rings called races. The relative m ...

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. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion 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: ''Svenska Kullagerfabriken''; 'Swedish Ball Bearing Factory') is a Swedish bearing and seal manufacturing company founded in Gothenburg, Sweden, in 1907. The company manufactures and supplies bearings, seals, lubrication and l ...

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 ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...

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. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Thicknesses can vary significantly; ex ...

(stamped or laser-cut) *

Brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other with ...

(stamped or machined) *

Steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

(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 Schaeffler Group (''Schaeffler-Gruppe'' in German), is a German manufacturer of rolling element bearings for automotive, aerospace and industrial uses. It was founded in 1946 by brothers Dr. ...

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 incorporat ...

and

NSK Ltd. , also known in some markets as NSK Automation, is a large manufacturer of bearings globally and the largest in Japan. The company produces industrial machinery bearings, precision machinery and parts, and automotive bearings and components. ...

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 Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...

* Pulp and paper 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 electr ...

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 te ...

* Cranes and

swing bridge A swing bridge (or swing span bridge) is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the swing span (turning span) can then pi ...

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