Towed agricultural machinery: bearings developed to withstand harsh environments from NTN-SNR

<p style="text-align: center;"><img src="/ueditor/php/upload/image/20220117/1642394126574947.png" title="1642394126574947.png" alt="3.png"/></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">There’s an old saying: “no crops without fields, no wheat without manure”.<br/>But what is the real nature of this cultivated earth that towed agricultural machines turn, loosen and shape?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">From tillage to harvesting, numerous towed machines are used by farmers to help production. These machines, and even more so the<a href="https://www.sunspeedbearing.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: 16px; color: rgb(0, 112, 192);"><strong>bearings</strong></span></a> they rely on, are in direct contact with an often harsh environment.</span></p><p style="box-sizing: inherit; font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; margin: 0px 0px 0.5rem; padding: 0px; color: rgb(30, 30, 30); text-rendering: optimizelegibility; line-height: 1.4; font-size: 1.065rem; white-space: normal; background-color: rgb(255, 255, 255); text-align: justify;"><br/><span style="font-family: arial, helvetica, sans-serif; font-size: 16px; color: rgb(0, 0, 0);">What do we mean by a harsh environment? There are two types of pollutants:</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Solid pollutants:&nbsp;earth, sand, stones but also plant residues and hay bale twine.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Liquid pollutants:&nbsp;mud, manure, fertilisers but also clean water for washing. These pollutants include numerous materials that are abrasive (waste, twine) but also corrosive (manure, ammonium fertilisers).</span></p><p style="text-align: justify;"><br/><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Let’s focus on earth, but first: what actually is it?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">The earth on cultivated land contains&nbsp;solid constituents&nbsp;(mineral and organic material),&nbsp;liquids&nbsp;and&nbsp;gases. Pore space can make up 50% of the total volume, and this is filled with water or gas. Mineral constituents – or the&nbsp;mineral part&nbsp;– come from physical-chemical degradation of the source rock. Organic constituents – the&nbsp;organic part&nbsp;– come from decomposition of plant, animal and microbial life (fungi, bacteria). This part constitutes the humus, which plants require to grow.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">If we look at the mineral part in detail, it is made up of elements with different grain sizes, including:</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">grit and stones (grain size &gt; 2 mm)</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">sands (20 μm-0.2 mm)</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">limes (2 μm-20 μm)</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">granular clay (&lt; 2 μm)</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">All of these particles pose a threat to bearings.</span></p><p style="text-align: justify;"><br/><span style="font-family: arial, helvetica, sans-serif; font-size: 16px; color: rgb(0, 0, 0);">How does this affect the bearings?</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Grit and stones affect the exterior of <a href="https://www.wswbearings.com/products/bearing-unit/882.html" target="_blank" style="color: rgb(0, 112, 192); text-decoration: underline;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px; color: rgb(0, 112, 192);"><strong>bearing units </strong></span></a>(impact) but also have an&nbsp;abrasive action on external sections of the seals:&nbsp;robust shields are used in front of the seals&nbsp;to protect them.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">The smaller the grain size, the easier it is for the substance to get to the seals. Sand will be stopped with&nbsp;multi-lip seals, and for the finest particles that would not be kept out by&nbsp;the&nbsp;external lips of the seals, static grease barriers&nbsp;will be applied within the sealing systems to capture any tiny particles that make it through.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;"><br/></span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">If that is not enough, we keep going: new lips on seals, then grease barriers.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Due to the variety of pollution, and to keep the machine working effectively, the bearings must be equipped with&nbsp;seals specifically developed for this environment. There are many variants, dependent on the position of the bearing in the machine (from single to reinforced triple-lip seals,&nbsp;up to 8-lip seals). In addition, these parts must be fixed on to ductile cast iron bearings to achieve the necessary robustness against solid pollution.</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">&nbsp;</span></p><p style="text-align: justify;"><span style="font-family: arial, helvetica, sans-serif; font-size: 16px;">Some machines can have&nbsp;up to 100 bearings, so it is easy to see why the technical characteristics of these parts are so important!</span></p><p><br/></p>