The purpose of a retaining ring is to act as a shoulder to stop the sub-component or assemblies coming off the shaft or a housing bore. There are various retainer rings available from various manufacturers but all of them can be grouped under stamped and spiral wound rings. The retainer rings can also be categorised according to how the rings are assembled. ie Axially or Radially.
As the name suggests, Stamped ring sometimes call snap rings gets the name as it’s stamped from a tempered sheet metal and has a non-uniform cross sections.
Types of Retainers
There are various designs available from various manufacturers catering and addressing common short falls of the rings such as tolerance stack-up, clearance diameter, thrust load capacity, flexible and radial installation, assembly automation etc.
Most common types of Retainer rings are;
- External and internal circlips
- Spiral Rings
- External and internal Snap Rings
Other types you might come across are circlips with increased abutment to increase surface area which stops the component and heavy duty circlips to handle large axial load.
Material and finish
Most commonly the circlips are made using carbon spring steel. To cater for high corrosive and food industry stainless steel versions are available from various suppliers to standard DIN 1.4122. Suppliers also have phosphor bronze and berriylium copper retainers in their stock
Advantages of retaining rings
- Cheaper compared to other fastening methods
- Use less raw material for a given size
- Reduce and avoid complex machining such as threads and under cuts
- Compact design
- Can be assembly quicker
- No special training require for assembly
- Light weight
- Easy to install
- unlike threaded alternatives, significantly reduce production cost
- It can only be used once
- Special tool
- There will be a small play in axial direction to cater for tolerance build up
- Less shaft/housing preparation (threading, tapping, drilling, etc.)
- Reduced weight and size of finished design
- LOWER COSTS of raw material and labour