A Belleville washer or disc spring is a conical-shaped spring with an open center. It is shaped much like a washer and is typically smaller than a coiled spring. Because Belleville washers can bear a much larger load relative to its deflection rate than a coiled spring, they are ideal for cushioning heavy loads with short motion.
Belleville disc springs, like all springs, deflect under load. They are known for their ability to handle high loads with relatively low deflections. The load-to-deflection relationship is non-linear, especially as the load increases, making Belleville washers and disc springs ideal for applications involving constant thrust and heavy wear.
Here are the key benefits of Belleville washers and disc springs:
- Space Conservation
- Long Service Life
- Compatibility with Coiled Springs
- Versatility
- Enhanced Machinery Reliability
- Prevention of Bolt Failures
- Positioning Accuracy
- Minimized Thermal Expansion
- Self-Damping
- Even Load Distribution
- Shock Absorption
In certain applications where heavy loads are involved, adding a flat washer can enhance the effectiveness of a Belleville washer or disc spring by distributing the load more evenly. Additionally, flat washers can prevent Belleville washers or disc springs from damaging softer metals. This is especially crucial for preserving the integrity of bus bars, which are commonly made from aluminum to handle high current loads.
The spring rate of a Belleville washer or disc spring refers to the force required for a given amount of deflection, typically measured in lb/in or N/mm. Each spring has a unique spring rate determined by its geometry and material properties. To calculate the load at a specific deflection, factors such as Poisson’s ratio, Young’s modulus, outer diameter (De), inner diameter (Di), material thickness (t), and deflection-to-flat (ho) are considered.
Adjusting the load and deflection characteristics of Belleville washers or disc springs can be achieved by stacking multiple units, either in series or in parallel:
- Stacking in Parallel: Aligning washers or springs in the same direction increases the overall load capacity.
- Stacking in Series: Aligning washers or springs in opposite directions increases deflection.
Belleville disc springs can also be stacked using a combination of these configurations to meet specific application requirements. The optimal stacking arrangement depends on the application's needs and constraints. Our engineers are available to help determine the best configuration for your particular application.
Before deploying a Belleville washer or disc spring in an industrial setting, it's crucial to understand its limits. Calculating load and stress helps determine the failure point of the spring, indicating how much force (load) and deformation (stress) it can endure before failure occurs.
Fatigue life refers to the number of cycles a spring can handle before failing in a given application. This is influenced by the spring's dimensions, preload, final load, deflection, and the frequency of loading. Determining fatigue life ensures that your Belleville washer or disc spring can endure the stress it will encounter. If a single Belleville spring can't handle the stress, a well-designed stack of Bellevilles can optimize load and stress performance, extending the fatigue life.
Properly designed springs enhance efficiency and extend the service life of your equipment. Our engineers are available to assist with all aspects of Belleville washer and disc spring design, including load and stress calculations.
