In 1839, Isaac Babbitt invented the metal that now bears his name. He made the discovery in Taunton, Massachusetts, USA. The alloy went on to become very popular in certain industrial applications. This was particularly true of the automotive industry. It had a tendency to prefer various products produced from the material, including Babbitt bearings.
Description
Babbitt metal consisted originally of the following percentages of these metals:
- Tin: 89.3%
- Antimony: 7.1%
- Copper: 3.6%
Some companies still use this formula under the name “Genuine Babbitt.” They also market it as ASTM B-23 Grade 2 Babbitt. However, modern versions of this soft, non-ferrous white tin alloy material also exist and are more common for industrial use. They combine the three major metals but in different proportions.
This tin alloy is one of the most common surface coatings or coverings for journal bearings. The sacrificial metal provides the bearings with such properties as:
- Friction reduction – lower friction coefficient than ball bearings
- Smooth, slick surface
- Acts as a lubricant
- Galling resistant
The ability to sacrifice itself and act as a lubricant for the shaft gives the rotary Babbitt bearings a favorable advantage over other types of bearings.
Types
These metal rotary bearings come in different types. Examples include:
- Self-equalizing bearings
- Sleeve bearings:
- Tapered bearings
- Thrust bearings
- Tilting shoe bearings
In its various formats, Babbitt bearings find employment in many diverse applications. Although once popular for automotive parts, they now are components of various high-speed rotating equipment. Applications using Babbitt bearings include:
- Chillers
- Compressors
- Electric motors
- Gear drives
- Locomotives
- Marine applications
- Pumps
- Turbines
Babbitt Bearings
For more than 100 years, manufacturers and foundries have been producing the alloy Babbitt. Over the years, it has become a common coating for various types of bearings. While some past Babbitt-based applications now use ball or roller bearings, many still prefer to employ Babbitt bearings to achieve their purpose