Bearings for Industrial Gearboxes - NSK Europe - #9

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Industrial gearboxes 9 Strength of connecting parts Does deformation of the housing need to be taken into consideration? Does misalignment at the bearing position caused by shaft bending affect performance? Such issues can cause distinct additional loads within the bearings and therefore need to be fully understood. Friction One issue is to determine whether specific friction performance is required to maintain accurate motion. Another issue is to determine whether support is to be provided for a special gear that requires a low level of heat generation during operation. Bearing life This issue is quite simple: What are the actual requirements for bearing life? This is driven by the area of application intended for gear operation. If proven and historically reliable calculation methods for determining bearing life are applicable, dimensioning can be based on standard values. If such data is not available, more complex calculations for determining bearing life need to be performed. Safe static capacity It is important to analyse whether certain operating routines require particular focus on safe static bearing operation, e.g. if the bearing is employed in excavators which have to cope with sudden, strong impacts. Significant plastic deformation has to be minimised to prevent premature damage and to guarantee smooth operation. Environmental conditions This is a complex issue. Environmental conditions, i.e. whether the machine has to operate in a roofed building or whether it is exposed to dust, sand, strong insulation, high humidity or rain, all affect lubrication and selection of the bearing type, sealing and fits. Are there any aggressive agents? What is the ambient temperature? Is the bearing exposed to separate heating or cooling? Do other machines cause vibrations when the gear is in standstill operating mode? Lubrication It needs to be determined whether there are certain conditions stipulated for lubrication of the rolling bearings or if oil lubrication is required in individual cases. Is centralised oil lubrication feasible for all bearing locations? Does leakage of lubricant (even in very small quantities) affect operation of the plant or the overall production process? Assembly It is vital to understand whether mass production is planned or whether products are to be individually hand built. As a rule rolling bearings made to bespoke designs need to be assembled with the help of special gauges. Costs for such devices are more likely to be amortised in series production. It is not only essential to determine the complexity of bearing design for initial assembly. If the gears are to be disassembled at regular intervals due to maintenance, easy handling is highly dependent on the assembling and disassembling of the bearing. Economy Is increased complexity of bearing design justifiable in terms of the benefit of increased bearing performance and operational reliability? Above all, it needs to be determined whether increased costs for the bearing are acceptable in view of easier handling during maintenance.