Bearings are undergoing a silent revolution, and in the process getting smaller, lighter, more reliable and less costly.
SKF or Svenska Kullager Fabriken stands for Swedish Ball Bearing Factory. Not many know the full-form of the three letters, SKF, and according to industry sources, SKF is so equivalent of bearings that all it takes to start a bearing company is three letters! This may sound exaggerated but the fact is that SKF has come to be a generic name almost when it comes to bearings. SKF, however, does not make only bearings and has used its bearing making experience spanning over 100 years to transform itself into a technology company that is "driving knowledge" into various areas including its core area of competence bearings.
SKFs participation in areas like machine tools, automobiles, aerospace and renewable energy sources like windmills, generators, etc, speaks about the companys drive forward as a technology company from the one that started out as part of a mechanical cultured bearing-making factory. Commanding a 15 per cent market share in Asia, 53 per cent market share in Europe, 20 per cent market share in North America and 5 per cent market share in Latin America, SKFs automotive market share stands at 31 per cent. Much of this comes from bearing related solutions even as mechatronics and lubrication has begun to get interesting. "When it comes to bearing related applications in automobiles", says M J Abraham, GM (sales & business development), SKF India, customers are demanding reliable, maintenance free, long life, low friction solutions that enhance fuel efficiency, performance and do not adversely affect the cost of ownership".
"Factors like the 4-wheeler market in India is shifting away from A-segment and towards B and C-segment, diesel vehicles are inexorably gaining market share and growing market segmentation", says Abraham, "drive the technological changes in the field of bearings". With automotive clients like GM, V W, Peugeot, Ford, Nissan, Daimler Chrysler, ZF, DAF, Volvo, MAN, Arvin Meritor, Temot, etc, SKF has been designing various bearing applications and products to meet the customer demands. Moving away from stand-alone bearing units, engineers at SKF are working closely with their automotive clients to come up with easily renewable, serviceable as well as cost effective solutions like various types of hub bearing units and sealing solutions. "Unlike the stand-alone bearings of yesteryear, these bearing units", says Abraham, "are of a modular design, are designed for the life of the car, greased and sealed for life, have simplified arrangements and enable easy adjustment and assembly".
Consider a typical hub-bearing unit (HBU) of a modern car used for driven front and rear wheels with rotating inner rings. The main components, an outer ring and two inner rings are matched with the ball set to give the correct clearance. This hub unit containing the bearing is greased for life. Yet another example is a HBU unit used with rotating outer ring for non-driven front or rear wheels. The flange of this unit is tough, with threaded holes or studs and a spigot to centre and mount brake and wheel. Alternative designs are available for rotating inner rings on driven wheels. In this case, the outer ring is bolted to the suspension. The HBU of the third type is typically used on driven front wheels and non-driven rear wheels. On this type of a HBU, the outer flange is bolted to the suspension. The rotating inner ring with its tough flange, spigot and threaded holes is designed for mounting of the brake and wheel. Alternative designs are available for non-driven wheels.
"Hub units are preferred to stand-alone units even if they pose greater challenges of design and application", says Abraham, " because thats the way to future". He adds, "We are in discussion with Tata Motors over shifting to HBU by replacing the stand-alone taper roller bearings that are at present robustness to the design, reduce noise, improve serviceability, reduce assembly time and system cost, improve vehicle performance and handling and enable integration of intelligent functions".
SKF engineers are working on transmission solutions. Stand-alone bearings are being replaced by solutions like the bearing carriers, which reduce power loss, enhance power density, enable downsizing and thus realise design flexibility and weight reduction. Solutions like bearing carriers also allow integration of functions, elevate reliability and bring down the costs.
For engines, SKF engineers are exploring second-generation idler gears, auto-belt tensioners, smart auto-belt tensioners and intelligent auto-belt tensioners. These devices may sound similar, but each one of them aims at bettering each other with the aim to increase belt life, compensate for temperature variations, reduce belt vibration and noise, automatically and accurately set the initial belt tension. In one of these concepts, SKF engineers are exploring the idea of including an electronic device to control the belt tension and detect in advance, belt failure.
"Mechatronics is one area where bearing solutions are playing a big role", says Abraham. Talking about auto clients, Abraham adds, "We supply bearing of the McPherson strut for the Maruti Suzuki Swift via Delphi. Our clients include M&M, Proton of Malaysia and Tata Motors."
|Posted : 8/31/2005|