How and why you should use a wave spring for bearing preload

<p style="text-align: center;"><img src="/ueditor/php/upload/image/20221011/1665475563801165.png" title="1665475563801165.png" alt="1.png"/></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Preloading a Bearing: What is Preloading, How to Preload, Why Should You Preload?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">What do we mean when we say “preload”?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">A <a href="https://www.wswbearings.com/products/catalogue.html" target="_blank" style="color: rgb(0, 112, 192); text-decoration: underline;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px; color: rgb(0, 112, 192);"><strong>bearing</strong></span></a> is designed to move freely and has multiple moving parts that work together as one unit. Tolerance stack up from both manufacturing and assembly can quickly cause issues.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">This is where preloading a bearing comes in.&nbsp;Preloading a bearing&nbsp;involves providing a sustained axial load to the bearing.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">So how do we preload a bearing? Are there different types?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">There are two main methods to preload a bearing. The first is solid preload, which is achieved by holding inner and outer races in place with a locking mechanism.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">The more common, simpler, and less expensive method is&nbsp;spring preload, which is achieved by using a spring to apply a constant axial load on one side. A Smalley single-turn wave spring provides necessary preload force between the inner or outer races while also compensating for any tolerance stack-ups or thermal misalignments. Play is reduced both axially and radially, as depicted in the image below.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">So what’s the big deal, why do we preload bearings?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Controlling play is necessary to maintain bearing functionality and longevity. Preloading a bearing provides constant contact between the bearing type (ball, needle, etc.) and bearing races. The sustained load provided by the spring eliminates axial and radial play, among other benefits. The overall goal of preloading is to prolong bearing life, and therefore, your application.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Advantages of Spring Preload</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Properly preloading a bearing will prolong bearing life. Using a spring for preload is critical for high-precision or high-speed applications, as it essentially eliminates the need for holding tighter tolerances and helps withstand high operating speeds.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Benefits</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Axial and radial play control<br/>Ball complement and bearing races mate reliably and take up dimensional variation.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Less wear on bearing<br/>Greater load sharing between bearings due to wave design.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Vibration and noise reduction<br/>Quieter assemblies, even in high-vibration applications.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Eliminate ball skidding<br/>Constant force is applied for smooth movement.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Precise shaft positioning<br/>Wave spring keeps shaft centered for optimal centrifugal distribution.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Selecting a Spring for Preloading</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">What type of spring should I use to preload a bearing?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Every application is unique, which makes selecting the proper wave spring very important.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">It’s important to consider overall tolerances, as placing too much preload on the bearing can reduce longevity, while too little can cause higher noise output in high vibration systems.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">Smalley’s bearing preload wave spring&nbsp;SSB series&nbsp;is carefully designed with the application in mind. The two types of single-turn wave springs we offer are gap and overlap.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">As the name suggests, the gap type has ends that are split, while the overlap type has overlapped ends. Both end configurations are free to move around the circumference as the spring is compressed, which is an advantage over traditional&nbsp;wave washers. Wave washers can bind, or become rigid, if pushed into the cavity too much, causing the spring load to become unpredictable.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">We have over 300+ standard parts available in carbon steel and stainless steel to match popular bearing sizes. Find your size by checking out the&nbsp;bearing cross-reference table.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 14px;">If you’re looking for higher force applications, a&nbsp;Nested&nbsp;spring is another type of spring we offer that can accommodate higher preload requirements. A&nbsp;three-turn Nested spring is pictured in the bearing application below.</span></p><p><br/></p>