Part washer and part spring, a Belleville washer will fulfill a specific role in your application. This conical-shaped washer may also be referred to as a conical spring or disc spring, but is more commonly known for inventor Julian Belleville. |
Some manufacturers brand lightweight conical disc spring washers with the Belleville name. Others use the names interchangeably, which can lead to confusion in the industry.
Similar to a flat washer, this type of fastener has an outside diameter and a center hole. The metal disc is not flat, but rather formed as a cone with a conical height or depth used as fastener specification.
Belleville washers are available in stainless steel, zinc plated steel and nickel alloy. Certain applications benefit from an oiled washer, and these washers present an economical choice that delivers good value and performance.
You may also come across a deflection force when specifying Belleville washers. This allows you to find the ideal size and thickness for your application, creating just the right amount of deflection. Consider stacking to create unusual or unspecified levels of deflection.
Belleville washers are effective on static applications to produce a spring movement or deflection, thanks to the conical shape and placement. In bearings and other joints, this washer can provide flex.
Your fastener distributor will carry a wide range of Belleville washer sizes, from 3/16" or 4.75mm to 2.5" or 63.50mm in diameter. Conical height tends to range from a slight cone at 3/16-inch to a more pronounced angle of 3/4-inch.
Weapons, such as landmines and rifles, often include Belleville washers. The washer plays a key role in landmines, receiving pressure from the trigger and activating the firing pin to set off the explosion. Stacks of disc spring washers may be used in rifles to replace traditional springs.
Stacking Belleville Washers
This type of washer can be stacked two ways to create greater spring or a stiffer joint. When Belleville washers are stacked in the same direction, the spring effect is lessened and a stiffer joint results with the same levels of deflection. This method of application is often called parallel stacking or parallel stacks.
By stacking in the alternate direction conical spring washers create a more pronounced spring with higher levels of deflection. This application method is commonly termed series stacking or series stack, similar to a series of springs creating an extended effect. Series lose deflection over time as bottoming out occurs.
In some cases these washers can be stacked in a mix-and-match pattern, parallel stacks lined up with series stacks. A general rule of thumb to remember is that no more than four washers can be used in a parallel stack.
Parallel stacks result in additional friction (between the washers), but will also absorb higher levels of vibration. Your fastener distributor can calculate the spring rate of parallel and series stacks, allowing you to spec your application accurately.
For weapons and a wide range of other applications in many different industries, the Belleville washer provides spring, resistance to vibration and significant spacing. Talk to your fastener distributor about how this uniquely designed washer can improve the design of your product or equipment.
Mike Moore is published on more than 300 websites. He writes about industrial fasteners and building, commercial building, and home building projects . He is published on various website including http://www.melfast.com
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