Types of Retaining Rings:

What are Retaining Rings?

Types of Retaining Rings: Definition, Uses, Advantages & Disadvantages :- Retaining rings, which are widely also regarded as circlips or snap rings are fasteners made out of metal which are installed into a groove which is present on a shaft, or in a bore or housing to retain an assembly. The devices hold the parts in their place using a lightweight, compact design which does not require a huge amount of machining operations compared to the other fastening techniques. ( Types of Fasteners )

Engineers usually differentiate the retaining rings based on their applications:

• Installation and removal requirements

• Expected force load(s) on the ring

• Conditions and operating environment

• Cost

• Rotational speed

The size of retaining rings can vary from 1mm to 1m in diameter. A variety of combinations of shape, style, size and material may even result in designs that perform efficiently in a variety of applications and industries. Taking example of a standard automobile, for example, can have as many as 50 retaining rings in systems which consists of steering, safety equipment, powertrain, etc.

Retaining rings also find their use in several other things, such as wind turbines, fitness equipment, bearing retention, doorknobs, bicycles, gas pumps, in office furniture, and many others.

1. Spiral Retaining Rings

Spiral retaining rings can be of two types: either single-turn or multi-turn, depending upon the needs and situation. Spiral-wound, Multi-turn retaining rings most commonly comprise of two or more curvatures of wire material with rounded edges which is in-house rolled flat. The edge of the material is coiled to give a gapless ring with an angle of retention of as much as 360º. Since there are no assembly lugs which are present in tapered retaining rings, spiral rings offer space savings in a radial direction.

3. Tapered Retaining Rings

A) Axial Assembled

It is generally fitted along the Centre-point of an axis (horizontally). These rings have a “tapered-section.” When you apply pressure to compress the lugs so as to fit the ring in a housing (or expand them in order to install it over a shaft), the height of the ring tends to get on a descending side symmetrically from the top to the ends which are free. This construction is the reason for the rings to impose a circular shape when it is proceeded inside the groove, which then allows the ring to have a stronger grip on the bottom of the groove along the entire edge of the ring. This feature provides the system with much needed high thrust load capacity.

B) Radial Assembled

These rings are installed along the circle (vertically). These retaining rings with external shafts are designed for conditions which are characterized by thrust loadings which are low. They do not have lug holes or lugs, and do not extend as further around the groove’s circumference as their axial counterparts, thus they tend to absorb less force. But for most of its applications they are pretty much cost effective.

C) Self-Locking

It is installed along the Centre-point of an axis (vertically)

1. Come in various sizes including small sizes for applications with thrust loadings which are very low.

2. They do not compulsorily require a groove for their installation.

3. Most of them cannot be easily removed once they are installed.

4. Constant Section Retaining Rings

As the name suggests, Constant section retaining rings consists of a constant, uniform section. This simply means that the material taken in use for the construction of the ring is of the same width throughout any point considered on the ring circumference. They usually cost less than spiral retaining rings and tapered retaining rings and are only known to have three-point contact with the groove.

Advantages of constant section containing rings

5. Custom Retaining Rings

Retaining rings can also be customized as per the requirements of the application. Usually, rings produced from coiling are comparatively easier to customize. Often not much of a complex setup is required (with no tooling) to produce any specific ring. If the application requires a specific configuration or end type, this is easier to produce from a coiled ring rather than with the help of a stamped ring. Custom rings can be manufactured in sizes which range from 0.157 in. (or 4 mm) to 120 in. or 3,000 mm in diameter. A custom stamped ring would ask for an additional die and setup.