Bearing retainers, also known as bearing cages, are used in rotary and linear bearings to separate and maintain a certain distance between rolling elements, such as balls, needle rollers, and rollers. Bearing retainers aid in extending bearing lifespan by reducing wear between parts, reducing heat build-up, and reducing wear between elements.
There are two fundamental types of bearing cage designs in rotary bearings: crown and ribbon. Crown retainers have an open-ball pocket design with a single component. Ribbon retainers are made of two pieces with an open-ball pocket design.
To determine the right type of bearing retainers to utilise for a certain application, consult the bearing manufacturer. It should be noted, however, that bearings with retainers are not always appropriate. A full-complement bearing with no holding mechanism, for example, may be recommended in applications with moderate speeds and large loads. Choosing bearing retainers or bearing cages necessitates an examination of materials and product requirements.
Metals such as heat-treated aluminium, solid bronze, or pressed steel are used to make bearing retainers or bearing cages.
Non-metal materials such as nylon, PTFE, and phenolic resins are used in others. Steel that has been pressed is a popular option.
Brass cages are typically utilised in severe or corrosive situations because they offer acceptable noise characteristics.
For spindle bearings and machine tool applications, phenolic or fiber-resin cages are used.
These bearing cages, also known as bearing retainers, are relatively light and can resist high speeds and large loads.