What is the purpose of the bearing retainer and what benefits accompany different retainer materials?
The retainer (also called cage or separator) is used to separate the balls and equally position them around the bearing raceway. Some retainer materials contain lubricant for extended bearing life. Retainers for ball bearings are generally available in two designs. The most universal is a 2-piece closed ball pocket design called a ribbon retainer. A single piece open ball pocket design is called a crown retainer. Crown retainers are available in a variety of metal and nonmetal options. PACAMOR KUBAR BEARINGS offers 440C steel retainers in both crown and ribbon designs and plastic crown retainers in either Phenolic or Torlon (polyamide-imide) materials. Phenolic and Torlon retainers are excellent options for high-speed applications. Torlon offers additional bearing life under steam autoclave conditions but requires regular lubrication at maintenance intervals. Phenolic is very forgiving under lube starved and low maintenance environments.
