WHITE PAPER How Pre-Assembled Disc Spring Stacks Help Manufacturers Save Time, Money and Ensure Quality by John Valvoda - Disc Spring Application Specialist SPIROL International Corporation One of the most demanding and complicated components to construct in a production environment is the Disc Spring Stack. Disc Springs (sometimes referred to as Belleville springs / conical washers) are used in stacks to achieve very specific height, force and travel requirements within an assembly. Disc Spring Stacks can be constructed in a variety of formations including: in series, in parallel, and in both series and parallel. Methods of Stacking IN PARALLEL Deflection: Same as single Disc Deflection: Single Disc multiplied by the number of Discs Deflection: Single Disc multiplied by the number of Discs in series Force: Same as single Disc Force: Single Disc multiplied by the number of parallel Discs in a set Force: Single Disc multiplied by the number of Discs Figure 1 SPIROL Pre-Assembled Disc Spring Stack with easy-to-peel perforated tab The Disc Spring’s outer diameter within the stack commonly ranges in size from 8 mm up to 200 mm. Some Disc Spring Stacks may contain Thrust Washers for stability (Figure 2). Disc Springs stacked in parallel are often lubricated to reduce friction between the surfaces of the individual Discs to curtail heat buildup that could otherwise be detrimental to the performance of the Disc Stack within the assembly. Given all of the variables that can go into the design of a Disc Spring Stack, there is no one universal rule on how to construct a stack. When a Disc Spring Stack design is finalised and ready for production, the steps of creating the stack for the assembly begins. It is at this stage that important decisions need to be made: • • • • • • • Where to source the Disc Springs / Belleville washers? What size Disc Springs are being used, what configuration do the Disc Springs need to be in, and how will this affect the production time needed to construct each stack? If the Disc Stack requires lubrication – what lubricant will be used and what is the best method to apply the lubricant consistently on each Disc Spring? Who will construct the Disc Stacks? How to train the assembler(s) to place each Disc Spring in its proper orientation every time? Does a jig need to be constructed to assist with the assembling of the Disc Stacks? How is quality checked on each Disc Spring Stack to ensure it is constructed correctly? Figure 2 Disc Spring Stack with

These questions need to be Innovative considered up front since someSolutions. Disc Spring Fastening Stacks require technically skilled employees to construct the stack while Lower others are more straightforward. If oneAssembly Disc Spring in Costs. a stack is missing or is placed in an incorrect orientation, the performance of the Disc Spring Stack, as well as the life cycle of the product in which it is used, will be impacted. The same holds true with lubricants used between each Disc Spring stacked in parallel. Too much or too little lubrication may have a drastic effect on friction. Any...