Last year I was studying the true costs of lubrication in bearing systems. Since we manufacture oil and maintenance-free plastic bearings, it's not hard to understand my agenda in doing this, but even I was surprised.
Over and over again the main reasons cited as the causes of bearing failures were lubrication-related issues. In fact, one major ball-bearing manufacturer completed a study claiming 54% of all bearings failed due to lubrication issues, while another one said this percentage was closer to 80%.
Yet many companies I visit do not feel the up-front cost savings of DryLin® linear bearings versus other bearings - which can be between 25-50% - justify the re-design.
However, I would challenge you to consider the other costs associated with ball bearings: for example, how much cost is incurred due to machine downtime? How much does it cost a plant to lubricate bearing points? How much do all the grease lines, fittings and lubrication systems actually add to the overall cost of a bearing system?