Retaining ring

A retaining ring is a fastener that holds components or assemblies onto a shaft or in a housing/bore when installed in a groove. Once installed, the exposed portion acts as a shoulder which retains the specific component or assembly. Circlips are a type of retaining ring.

Self-locking retaining rings may be installed in applications where there is no groove.

Retaining rings are typically made from carbon steel, stainless steel or beryllium copper and may feature a variety of finishes for corrosion protection depending on the type of environment in which they are used.

There are three main types of retaining rings available, each of which may then be broken down into sub-types depending on unique application needs:

Tapered section retaining rings decrease symmetrically from the center to the free ends, remaining circular when contracted or expanded within the limits of normal use. This assures contact with the groove along the entire periphery of the ring. These rings may be installed axially (horizontally along the center point of an axis) or radially (externally along the radius of a circle). Depending on the size of the ring in question, it may be manufactured in one of two ways:

Axially assembled retaining rings are installed into machined grooves in housings/bores (internal) or on shafts (external). These rings are manufactured with lug holes—small holes in the lugs of both axial internal and external retaining rings—that are used to install/remove them, using pliers designed for this purpose.

Inverted retaining rings are a variation of axially assembled rings in which the lug holes are inverted to fit in the bottom of the groove. Inverting the lugs allows greater clearance on a shaft or in a housing and forms a higher uniform shoulder good for retaining bearings and other components with large corner radii or chamfers.

Beveled retaining rings feature a 15° beveled or angled edge. This angle allows the ring to wedge itself between the groove and the retained part until it can go no farther, effectively “locking” everything in place. Think of placing a cork in a bottle. The cork is forced into the opening until it is wedged as far into the opening as possible. The same thing happens when a beveled retaining ring is installed into an application. The ring is wedging itself into place between the groove wall and the retained part, resulting in what is referred to as rigid end-play take-up.

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Wikipedia