Properties and Uses of the Belleville Washer


Properties and Uses of Belleville Washers

Julian F. Belleville was an inventor in the 1800s who combined a spring and a flat metal washer into one part. The shape is frusto-conical, which means it looks like a cone that has the top portion cut off creating a hole in the middle. Other names for this type of washer are conical spring, cupped spring, and disc spring or a combination of these names. Some of the characteristics of Belleville washers are that they creep less than other types of washers, occupy the space they are placed in more efficiently, and hold up well under stress.

Belleville washers are different from helical or coil springs in that they work in small spaces, supporting high loads with small deflections. Helical springs are the type you would find on a trampoline or in a ball point pen casing. In industrial applications, these washers eliminate or decrease thermal expansion, vibration, and bolt creep issues among others.

Using a stack of Belleville washers imparts more load flexibility by stacking the washers in three different variations. The first variation is multiple washers stacked the same way. The second is stacking the washers opposite from each other with the third variation being a combination of parallel and opposite stacking which will increase both the load bearing and the deflection. Deflection is defined as the motion of the spring arms when a load is applied or the load is removed.

One of these washers has an assigned load for a specific deflection. When you stack two washers in a parallel configuration, the yield will double the load and three parallel, stacked washers will triple the load, and so on. A washer stack in series or a configuration of parallel and opposite washers increases the deflection. Furthermore, you can increase or decrease the load as well as the deflection by simply adding more washers or removing some of the existing washers. Changing the sequence of the parallel and opposite stacked washers will also change the load.

We manufacture Belleville washers that are used on the locking and latching devices of oven doors so that the oven temperatures are maintained and for efficiency maximization. Fishing reels have a drag system that also uses these washers for pressure application. The drag changes as the washer is squeezed, which increases the spring force and more drag. As the washer pressure decreases, the drag is reduced. When the fisherman wants to change the drag on the reel, the washer allows for fine tuning.

Paintball and air guns utilize Belleville stacks in their regulators for pressure settings. The washer stacks provide the pressure and spring rate the guns need and for the fine tuning of the pressure. They make the guns reliable and easy to use. Airplane landing gear has a tendency to oscillate when the wheels hit bumps on the runways. Belleville washers reduce the vibration and the shimmying in the nose gear as well. Formula One race cars, deep sea drilling rigs, the military, electrical utility companies, and heavy equipment clutches and brakes use these washers as well. You can even find Belleville washers in use on the International Space Station.

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