Ball Bearing
notes: label: Description
content: This is a set of eight bearing balls of varying sizes. For optimum bearing performance, balls in a bearing must be perfect spheres of exactly uniform size. If not, the bearing’s load will focus on the irregular ball, leading to failure in the bearing. During the middle of the 20th century, balls were manufactured by the “cold heading” process. In cold heading a piece of cylindrical steel wire is cut and compressed by a spherical die. This forms rough balls with protrusions at the top and around the equator. The balls go into a grinder to remove these protrusions in a process called deflashing. Further heating, grinding, lapping, and cleaning leaves uniform balls ready to be added to its matching cage or raceway to make a fully assembled bearing.
label: Description
content: Simple bearings have been used for thousands of years reducing friction on turning parts like the axles of carts. In the late 1800s and early 1900s advances in machining and production expanded bearing use in all types of machines greatly increasing their life and precision. Bearings reduce friction on turning surfaces and keep them running true. Bearings come in a variety of shapes and sizes (including ball, roller, tapered, and simple friction). Modern bearings are often set in an inner and outer ring (called a race) sometimes with cages (separators) spacing the bearings. Changes to the size, shape, alignment, race, and cage allow for bearings to be used in almost any industry—from industrial turbines and automobiles to household mixers and computer hard drives.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Mechanical and Civil Engineering
label: See more items in
content: Industry & Manufacturing
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MC.336100.01
label: catalog number
content: 336100.01
label: accession number
content: 1977.0585
objectType: label: Object Name
content: bearing
label: Object Name
content: bearings
physicalDescription: label: Measurements
content: overall - large bearing: 5 1/4 in x 5 1/4 in x 5 1/4 in; 13.335 cm x 13.335 cm x 13.335 cm
label: Measurements
content: overall - small bearings: 3 in x 3 in x 3 in; 7.62 cm x 7.62 cm x 7.62 cm