Preload Disc Springs

We offer a range of preload disc springs that were originally designed for ball bearings even though they have found use in a broader set of applications, their dimensions match the ball bearing designations. More and more often we are called on to apply preload disc springs for much larger applications, such as wind turbines and steel mill rolling lines.

Preload application

Preload disc springs are often referred to as bearing springs, which hints at their original design. Every ball bearing is designed and manufactured with an amount of clearance between the balls/rollers and the raceway. This leads to three issues that need to be addressed:

• Elimination of lateral play, and the
• Reduction of noise at high revolutions, and most importantly,
• Elimination of unwanted vibrations

The use of preload disc springs on bearing applications has the following advantages:

1. Thermal effects from the expansion of metal as it heats are greatly reduced,
2. Tolerance drift is far less of an issue as the disc springs can be used in stacks
3. Bearing assemblies can run with greatly reduced noise levels
4. Lateral movement is reduced and positional integrity of the bearing is maintained
5. Vibrations at high speeds are greatly reduced, from the elimination of harmonic frequencies that might hit resonance

Characteristics of Preload Disc Springs

Preload disc springs have the following Load Characteristics:

• The ratio of the Outer Diameter - (O_d) to material thickness - (t), is high i.e. greater than 40. Note the maximum for a DIN 2093 is 40.
• The ratio of the cone height - (h₀) to material thickness -(t) is greater than 1 and this means the curve is non-linear and progressive in nature.

This translates into the following:

• Working forces are much lower than those expected from the DIN 2093 disc springs - for example, even on the preload disc springs of O_d greater than 200mm, the design load is never greater than 1500 Newtons
• The induced stresses from loading are comparatively lower than the yield point of the underlying base material, so plastic deformation does not occur.
• If used correctly and properly maintained, operational life is measured in the millions of cycles.

Preload Application

In some applications the rate of change needed between load/force and compression/deflection/compression can either be high or low, and for this purpose, disc springs come in two types, plain or non-slotted and slotted.

Despite the original intent of these disc springs for use in bearing assemblies, they are used in a much wider range of applications than most engineers appreciate from sewing machines, to flow valves, vibration insulators, face seals, pressure relief valves etc.