Revolox® ‘Dome and Slot’ Self-Locking Ring: What is it, How Does it Work, and When Should I Use One?

What is a Revolox^® ‘Dome and Slot’ Self-Locking Ring?

Let’s first define what a self-locking ring is.

Spirolox®, a division of Smalley, invented self-locking rings back in 1958. There are two types of self-locking rings, ‘Tab and Slot’ and ‘Dome and Slot’.

So, what is it?

A self-locking ring is a custom retaining ring feature that increases a ring’s rotational capacity. They are typically specified for high RPM applications such as electric motors.

A Revolox^® ‘Dome and Slot’ Self-Locking Ring is one type of self-locking ring.

How Does the Self-Locking Feature On a Revolox^® Self-Locking Ring Work?

The self-locking feature consists of a ‘dome and slot’ design that prevents the ring from expanding due to centrifugal forces.

Fig 1. Revolox^® Self-Locking Ring with dome and slot labeled.

The dome feature is punched into the underside of the ring, resulting in a dome shape on the opposing side of the ring. It’s integral that the dome shape protrudes above the surface of the ring, but with no shearing. The slot portion is created by cutting into the mating turn.

The dome and slot are located such that the dome is trapped within the slot once installed in a groove, thus locking into place.

As the ring rotates, it expands, engaging the dome and the slot and preventing further expansion.

What Are the Advantages of Using a Revolox^® Self-Locking Ring for High Rotational Capacity Applications?

Revolox^® Self-Locking Rings have the same benefits as ‘Tab and Slot’ Self-Locking Rings, with the following additional advantages.

1. Significantly higher RPM capacity over an equivalent non-locking retaining ring

Revolox^® Self-Locking Rings were tested and optimized for high RPM performance. Contact Smalley Engineers to discuss RPM capabilities in your application.

Fig 2. The ‘dome and slot’ design prevents ring expansion.

2. Ease of installation

The sturdy ‘dome and slot’ design is not easily damaged during installation.

3. Lightweight

With a part weight approximately half the weight of a typical retaining ring, the lower part weight reduces rotating mass and therefore increases efficiency in the application.

4. Automated installation capabilities

Automated installation capabilities make Revolox^® Self-Locking Rings an ideal solution for high production volumes.

5. Inherently better-balanced than Tapered Section Retaining Rings (Circlips)

Revolox^® Self-Locking Rings have an inherently better-balanced design that helps decrease vibration.

You may want to consider other options if:​

• You’re looking for the highest RPM capacity

‘Tab and Slot’ Self-Locking Rings may offer higher RPM capacity over Revolox^® Self-Locking Rings.

Key Points

• A Self-Locking Retaining ring is a custom retaining ring feature that increases a ring’s rotational capacity
• The Revolox^® ‘Dome and Slot’ Self-Locking Ring consists of a ‘dome and slot’ design that traps the dome within the slot to prevent ring expansion
• Revolox^® ‘Dome and Slot’ Self-Locking Rings offer the same advantages as the ‘Tab and Slot’ style, but with additional benefits such as automated installation capabilities for high production volumes.
• Consult with a Smalley Engineer to determine what Self-Locking Ring style is appropriate for your unique application. 

Download the High RPM Retaining Ring Solutions Technical Guide

Download the E-Book today.

Next Steps?

Here are some additional resources beyond our E-Book that you might find helpful:

• Get started on high RPM design! Submit your Application Requirements. 
• Try out a sample – get free prototypes.
• Looking for more than just a high RPM ring? Explore our 2021 Ring and Spring Catalog and Design Guide.
  We have over 10,000 rings and springs in stock!
• Have a question? Contact a Smalley Engineer.