Every production line demands reliability in order to maximise efficiency and keep lost production time to a minimum. While proper planned maintenance is an effective tool, it can be expensive if equipment requires very frequent intervention. One option is to ensure that the equipment is fitted with components which are fit for purpose. For example, a large paper manufacturer was experiencing loss of production due to seized bearings on a tinting machine with annual costs of nearly EUR50,000 – a problem that has been solved by NSK.
The paper manufacturer was suffering from lost production time amounting to 4 hours per month due to seized bearings on a crucial tinting machine. An initial investigation by NSK engineers discovered that the standard bearings used were being contaminated with ink and that replacement was required prior to each production run using this machine.
While the bearing replacement task only took 4 hours, the costs soon mounted up when assessed over the year, with the actual replacement bearing cost making up a tiny fraction of the overall costs. The NSK engineers recommended the installation of stainless steel Molded-Oil bearings to combat the ingress of the ink. Acting on this advice, the customer has seen continuous operation of the tinting machine for over 12 months without incident or loss of production.
The new bearings have allowed the maintenance engineers to concentrate on other areas of the plant and also saved 4 hours every month in time and materials, amounting to a saving of EUR1400 per year. However, the biggest winner has been the production manager, who has seen his annual costs drop by nearly EUR50,000 thanks to a huge reduction in machine downtime, as well as improving overall efficiency and ensuring more deadlines are met ensuring customer’s orders delivered on time.
Molded-Oil bearings effectively address the problem of lubricant loss in bearings due to liquid ingress by remaining sealed and lubricating themselves internally. They are suited to many areas of manufacturing production where regular wash-down maintenance is required or where a production process involves non-lubricating liquids. The design can transform the performance of bearings, in terms of reliability, maintenance-free intervals and operation – in environments exposed to contamination. It also enables plant operators to make real cost savings by replacing existing, and often costly, methods of lubricating machine parts.
Good lubrication regime
Molded-Oil bearings use a polymer matrix containing lubricating oil. By providing a lubricating oil content of more than 50 per cent by weight it improves on other marketed oil-impregnated plastics, where the oil content is a mere few per cent by weight. The technology comprises lubricating oil in a polyolefin matrix. The characteristics of the material mean that a good lubrication regime is maintained. The mechanism of oil discharge from the matrix is temperature dependent; the higher the heat generation, the higher the oil discharge rate.
NSK offers its Molded-Oil technology on standard deep groove ball bearings, taper roller bearings and spherical roller bearings in outside diameter sizes up to 250mm. Prior to filling the bearings with Molded-Oil the interior surfaces are specially treated, resulting in a bearing torque that is slightly higher than that of standard grease-lubricated bearings.
Free copies of the Bearings for Paper Making Machines brochure are available from NSK. Further information about Molded-Oil bearings can be found at www.nskeurope.com.