The Basics
A Belleville washer or disc spring is a conical spring with an open center. It is shaped much like a washer and is usually smaller than a coil spring. Because Belleville washers can carry a greater load relative to their deflection rate than coil springs, they are ideal for cushioning heavy loads with short movements.
Like all springs, Belleville disc springs are deflected by the load. Disc washers and disc springs exhibit low deflection with respect to high loads. The relationship between load and deflection is non-linear, especially as the load increases. This quality makes Belleville washers and disc springs ideal for areas that have constant thrust and must withstand heavy wear.
Belleville washers and disc springs offer the following advantages.
▴ Space saving
▴ Provide long service life
▴ Can be used in conjunction with coil springs
▴ Offers excellent versatility when stacked in series or parallel
▴Increases mechanical reliability
▴ Prevents bolt failure
▴ Maintains ball bearing positioning accuracy
▴ Minimizes thermal expansion
▴Whether self damping
▴ distributes the load evenly
▴ Absorb shocks
Our engineers can help you determine the washer or spring needed to meet the requirements of your specific application.
Flat washers
In some cases where heavy loads must be carried, adding a flat washer increases the effectiveness of a disc washer or disc spring by helping to distribute the load. In other applications, flat washers can prevent the disc washer or disc spring from biting into softer metals. This is especially important to maintain the integrity of the sink bar, which is often made of aluminum to withstand high current load conditions.
HEGONG engineers can help you determine if flat washers are required for your specific application.
Spring Stiffness and Stacking
The spring stiffness of a Belleville washer or disc spring is the amount of force associated with a given deflection, measured in lb/in or N/mm. Each spring has its own spring stiffness, depending on its geometry and material. The formula for determining a specific deflection load uses Poisson's ratio, Young's modulus, and the outside diameter (De), inside diameter (Di), material thickness (t), and deflection to plane (ho).
The load/deflection ratio for a particular OD and ID can be changed by using multiple Belleville washers or disc springs stacked in series or parallel. Stacked Belleville washers and disc springs allow for precise customization of load and/or deflection.
▴ Parallel stacking (same direction) will increase the load.
▴Stacking in series (opposite direction) increases deflection.
▴Belleville disc springs can also be stacked as a combination of both alignments.
The exact configuration of Belleville washers or disc springs depends on the requirements and limitations of the application. Our engineers can help determine the configuration that will best meet your needs.
Understanding Load, Pressure and Fatigue Life
It is also important to know the limitations of a given Belleville washer or disc spring before putting it into service in an industrial environment. Calculating loads and stresses is one way to determine the failure point of a spring, including disc washers and disc springs. In short, it is a method of determining how much force (load) and how much tension (stress) a spring can withstand before it fails.
Fatigue life is the number of cycles a spring can withstand before it fails in a given application. Fatigue life depends on the size, preload, final load, deflection, and frequency of the spring or spring set. The purpose of determining fatigue life is to ensure that your disc washer or disc spring solution can withstand the stresses it is subjected to. In situations where a single Belleville cannot withstand the stress levels, a well-designed Belleville stack can alter load and stress performance and extend fatigue life.
Well-engineered springs help improve equipment efficiency and extend service life. Our engineers are available to assist with all aspects of Belleville washer and disc spring design, including load and stress calculations.
