Posted to News on 26th Feb 2010, 11:46
Free guide to selecting gearbox bearings
NSK is publishing a new free guide, Rolling Bearings for Industrial Gearboxes. This will, according to the company, make the process of selecting bearings for all gearbox types more straightforward, structured and transparent.
Bearings are available form NSK for all aspects of gearbox operation, and the new publication reflects this in the breadth of the subject matter, which is designed to help users understand all the key areas that must be considered when selecting particular bearing types for converting and translating motion.
Extending to over 30 pages, Rolling Bearings for Industrial Gearboxes is divided into eight sections. Section one gives an overview of all current gear designs - worm, hypoid bevel, epicyclics, spur and bevel types - and outlines their advantages and disadvantages. Section two then discusses the factors that affect bearing performance in gearboxes - such as load, speed, friction, environment, shaft arrangements, lubrication, assembly space and many more. All of these are considered individually, with guidance provided as to the relevant questions to ask regarding each specific factor.
Section three deals with bearing types and their characteristics; here the reader is helped by simple-to-use graphics. The first graphic shows the bearing types and their capabilities in terms of loads, speeds, misalignment, and lubrication medium. The second graphic extends this information with an easy-to-read table that gives at-a-glance references for the suitability of specific bearing types for a given set of operating parameters.
Technical details
The following sections, four and five, are the most technical of the publication. The former looks at bearing positions inside gearboxes; it considers support by fixed and floating bearings, adjusted bearing support and floating bearing support. Here, again, graphics are used for illustration; this time in the form of a two-page table that shows most types of bearing arrangements, provides comments and gives fields of application.
Next is a section that considers bearing life; this includes details on NSK's latest optimised methods and calculation procedures such as the ABLE-Forecaster (Advanced Bearing Life Equation) software, and STIFF, a program developed by NSK that considers important parameters such as deformation of shafts and housings, misalignment, displacement of the bearing itself (and adjacent bearings), as well as internal operating cycles.
The final three sections are devoted to materials, lubrication, the consequences of a lack of lubricant, and proper dimensioning of bearings. Regarding materials, the guide highlights NSK's development of Super TF steel. This material is claimed to set new benchmarks for reliable operation in contaminated operating conditions, or applications where high stress factors are encountered. The new material can be employed in a wide range of bearing types.
A section on lubrication provides a useful calculation of the quantity of oil required for optimum bearing performance; it considers whether oil or grease is best, and concludes with a graphic table giving details of damage caused by lubrication problems.
Completing what is a comprehensive yet concise publication, the final section deals with dimensioning of bearings. It gives procedures for fit selection and tabulates fits for radial bearings with housings.
Use the form on this page to request a callback or more information.
