Industrial Bearings Market in India :Issues and problems Ajay K Gupta Managing Director Kamtech Associates Pvt Ltd. www.bearingsindustry.com
Bearings of various types and sizes are used for different sectors The major sectors are as follows: • Automobiles • Railways • Electrical Motors • Electric Fans • Diesel Engines • Pumps • Machine Tools • Textile machinery and • Other heavy industries (Steel Plants , Sugar Plants, Process Plants, Heavy Engineering, Industries , Heavy Earth Moving Equipment , Cement Plants , Power Generation Units
Replacement Market • Replacement Demand is the after demand where as a part of the maintenance of the machines or rotating machine , the bearings are replaced by new bearings after itis failed asnatural life deterioration/ wear ortearor due to premature failures and need replacement The replacement market represents the demand arising on account of replacing the used and worn-out bearings. The size of replacement market is dependent on equipment population and frequency of maintenance. Replacement market accounts for 40% of total demand for bearing industry. The margins in this market are relatively higher placed as compared to OEM market.
Cont… • The replacement market is highly price sensitive and has higher share of unorganized players and cheaper imported bearings. Exhibit4 represent the bearing demand per sector. • From the inception of the industry, bearing manufacturing in the country is dependent on foreign technology. The organised sector of the industry has imported know-how from various internationally leading manufacturers of bearings. The import of technology is generally restricted to small and standard bearings. Technology borrowing specifically for special bearings has not taken place so far.
Imports • 30% of total demand for bearing industry is met by imports. While a part of the imports come through official channels, there is also a huge volume of illegal imports. Legal Imports generally represent the specialized bearings not manufactured in India. There are a large variants of imported bearings, each holding a small market share in India. • Though, the quality of bearings manufactured by large players in India is comparable to world standards, domestic manufacture is not viable due to the small size of the market segment. It becomes uneconomical to manufacture such type of bearings as it includes huge capital expenditure.
Cont… • Illegal imports generally represent the entry of spurious imports of bearings. In the past, the Indian bearings industry was highly protected on account of very high import duties ranging from 150% to 240% ad- valorem. As a result , illegal imports via smuggling and under invoicing of imports was the order of the day, accounting for a high 45-50% of total imports. While duty rates have come down over the last few years, a few countries like China, Russia, Eastern Europe dump their excess production at a very low rate. This leads to a huge price differential between domestic and imported bearings (almost 40-50%), encouraging imports.
Technological Interventions • The heavy dependence on borrowed technology indicates that continuous efforts towards development have not yielded the desired results. Moreover, in spite of collaborations the Indian industry generally has not achieved standards of quality close to international levels. Research and Development appears conspicuous more by its absence, in this industry.
Cont… • The industry undertakes routine development programmes from time to time, in terms of additional bearing sizes or increased production. • The various reasons that have been put forward for selection of a foreign collaborator are as follows : • — The advantages associated with an internationally renowned name. • — Favourable terms and conditions of collaboration. • — Quality of product. • —Assured access to latest developments at the international level.
COMPARISON OF TECHNICAL SPECIFICATIONS • Since the product is standardized internationally, the designs followed by the industry are more or less, the same. Technical specifications are restricted to basic parameters. Quality specifications adopted from the collaborator's specifications, vary usually. • The bearing manufacturers have been adopting the equipment technology suitable for low volume production. This was essentially due to the demand pattern of rolling bearings in the country being made up of a large diversified range of bearings in small quantities. In view of the very high cost of bearing equipment, most of the bearing manufacturers did not venture to change their equipment technology in favour of large batch production or line production.
THRUST AREAS FOR TECHNOLOGY The thrust areas for indigenous technology would include : • Development of indigenous machine tools and equipment for testing, equivalent to international standards of precision. • The suitability of these machines in the Indian working environment would be the critical factor. • Materials are available indigenously. However, the quality of tubes in particular, is not to the satisfaction of the industry. Moreover, consistency in supplies is also not experienced. Cleanliness of material needs to be improved to a great extent to enable the industry to take basic advantage of quality raw material. As regards forged rings, suppliers meeting sufficient quality standards need to be encouraged.
Cont… • Operational expertise of a very high calibre has to be achieved. • Maximum precision in the process, minimum handling damages, and maximum cleanliness should be observed to get the desired quality of bearings.
HANDLING AND STORAGE OF BEARINGS • If possible, determine when a bearing was manufactured and if it was properly stored before being purchased. Ask the bearing distributor about his storage and handling procedures. It might be prudent to have a representative from your company personally visit the bearing distributor to confirm how bearings are being stored. For example, a tapered roller bearing should be stored with the taper down and never stacked, one on top of another. • Store bearings in an attitude “angle” that will reduce or eliminate the possibility of damage to rolling elements and raceway. It may be weeks or months before the bearing is called into service. Reducing the risk of startup damage begins with proper storage. • Bearings are manufactured with extremely tight tolerances and therefore require special care when moving or handling. Consider them fragile at all times and make the effort to treat them as such. • Consider the proximity of the storeroom to areas of the plant that are affected by vibration. Could a railroad main line affect the storeroom? Does the plant have equipment that vibrates nearby buildings? Bearings subjected to even minor daily vibrations can become damaged while in storage. Take the necessary steps to insulate stored bearings from any vibrations. Always store bearings in a clean and sterile environment. Keep them free of moisture, dust, and chemicals.
Bearing installation and handling • Take care when removing old or damaged bearings from their shafts and housings. Be careful to not damage holders or surfaces where the new bearings will be installed. • • Clean all housings, shafts, holders, keyways, etc., before attempting to install a new bearing. Inspect the shafts and equipment for damage. Install new bearings in as clean and dry an environment as possible. If possible, use sterile gloves to prevent contamination. Contamination at this stage will ensure a shorter bearing life cycle. • • Carefully inspect the new bearing for any obvious damage that may have occurred during shipping, storage, or manufacture. Inspect bearings to determine if all parts are present. Bearings have been known to ship from the factory missing roller elements and other parts. Also, check for factory lubricant. Lack of lubricant from the factory can cause rust.
Storage of Bearings • a. Avoid storing bearings in places with high humidity. • b. Store bearings in a cool place. • c. If bearings come packed in a wooden box, take them out of the wooden box immediately, and store them on a shelf. • d. Do not take bearings out of the cardboard boxes or protective wrappings. • e. Do not stack bearings because the protective anti-rust compound may be squeezed out of bottom bearings.
Temperature’s Effects on Mounted Bearings • I can’t lay my hand on the bearing because it's operating too hot!" While this is a commonly heard complaint, most sleeve and rolling element bearings can operate successfully at temperatures well above the pain threshold of a human hand. The stabilized operating temperature of a bearing is the result of many factors. The key influences on operational temperature are bearing style, lubrication type, operational factors, environmental conditions and level of maintenance • The particular bearing style (ball, roller, sleeve, etc.), the shaft mounting style (slip fit, adapter mounted, press fit, etc.) and auxiliary items (housings, seals, shields, flingers, etc.) all contribute to a final operating temperature. For a given set of application conditions, a particular bearing type will generate friction given off as heat. A typical bearing temperature rise range would be 40° to 80°F (4° to 27°C) for most industrial applications. However, a bearing temperature rise over ambient of up to a 120°F (49°C) can be observed at extreme conditions
MOISTURE • Moisture is generally referred to as a chemical contaminant when suspended in lubricating oils. Its destructive effects in bearing applications can reach or exceed that of particle contamination, depending on various conditions. Like particles, vigilant control must be exercised over entry of water to minimize its accumulation in the lubricants and its damage to bearing surfaces • Once water enters the casing of a machine where bearings are used, such as an engine, turbine, or gear box, it may move through several chemical and physical states. These changes are complex, but important to understanding how to control and analyze its movements. To begin with, water will enter an oil in generally one of the five following ways
PRE LOAD • Preload is the force that is applied to a bearing assembly during installation to remove the axial play and to further compress the bearing to provide both axial and radial stiffness. It is an important design parameter, affecting rotational performance and lifetime of a bearing assembly. After preload, the resulting ball contact angle α must be considered
Minimum Loads • Rolling element bearings require minimum loads to function satisfactorily. This is because the balls or rollers must rotate when carrying the load. Skidding will occur if the load is not sufficient to overcome cage friction and the resistance from the lubricant, especially during periods of low temperature operation. • The consequent is damage to both raceways and rolling elements. Usually the load from the shaft assembly is sufficient to prevent this from happening. In cases where the load is not sufficient, the bearings can be pre-loaded by the use of springs. In some instances reduced bearing internal clearance may help but great caution should be taken to avoid a high pre-load condition, which can result in catastrophic failure
Minimizing Bearing Damage Inclusion-A fatigue crack starts just below the raceway surface at a nonmetallic inclusion (micro impurity) and propagates to the surface. Geometric Stress Concentration-Damage occurs in a localized region of high stress at the raceway edges due to high rolling loads and misalignment. Point Surface Origin-Damage originates at a localized, high-stress point on the raceway surface, typically caused by insufficient lubricant film thickness separating the bearing surfaces.
Degrees of Life enhancement Various degrees of power density can be applied to enhance bearing life and durability, Typically an enhanced bearing will provide a minimum of 1.5 times the life of a standard bearing, although in more severe operating conditions, performance gains of 4-5 times are not uncommon. To clearly identify the design and life enhancement potential of power dense bearings, the designer should make a detailed application analysis of the many bearing design variables as well as operating and environmental factors. Bearing manufacturers can apply advanced software to accurately quantify these effects.
Fully-enhanced bearings increase life by minimizing the three primary modes of fatigue damage through the incorporation of cleaner steel, super-finished rolling contact areas (rollers and raceways) and optimized geometry. Super-clean, air melt steel provides an additional 30 percent increase in life to fully enhanced bearings.
Selectively-enhanced bearings offer the flexibility of selecting or applying only those enhancements needed to economically optimize performance in specific applications. Service life can increase within the range shown in Figure and depends both on the specific enhancements chosen as well as the specific operating conditions. Such bearings fill the performance gap between standard and fully enhanced bearings. Selectively enhanced bearings are especially cost-effective in large bearings (8 to 84" OD), where fully-enhanced features may not be readily feasible.
Bearing selection • Procure the correct bearing for the application. Often, the replacement bearing is not compatible with the equipment where it is to be installed. Depending upon the age of the equipment, advances in bearing technologies may exist that make the OEM bearing obsolete. Knowing the limits of the equipment and what bearing best suits the application will save time and money. • • Determine the maximum load for the bearing. This is important both vertically and horizontally. • • Determine the minimum and maximum running speeds for the bearing. This will help determine the correct lubricant and bearing for the application. • • Determine all possible environmental conditions to which the bearing will be exposed. Very hot or cold environments often require varied bearing specifications. This may, in turn, change the type of lubricant and relubrication requirements as well.
Materials -- Improved micro-cleanness, alloys and processing techniques . Design -- Improved internal geometry, such as roller/race profiles, to carry higher loads and handle misalignment within a given envelope Tribology -- Optimized interaction of bearing surface topography with lubricants, lubricant additives and debris . Manufacturing -- Advances in processing techniques for surface finish, plus precision tolerances, improved profiles, material cleanness and heat treatment. Application Analysis -- Advanced performance-prediction tools that consider the effects of bearing design features as well as significant bearing environmental influences such as load zone, misalignment, lubrication, temperature, housing rigidity, load and speed
Bearing repair is not a new concept, nor has it changed a great deal over the years — and that's good news. Repairing damaged bearings is a precise science that has been fine-tuned over time through careful and gradual enhancements to provide superior results. Just as new designs and technologies improve bearings, growing expertise and technology of bearing repair continues to increase the reliability and performance of reconditioned bearings, keeping it an economical alternative to purchasing new bearings Knowing and understanding the value of bearing repair means knowing what repair can do, when to use it, and where to get it done.
Bearing Life Bearing life refers to the amount of time any bearing will perform in a specified operation before failure. Bearing life is commonly defined in terms of L-10 life, which is sometimes referred to as B-10. This is the life which 90% of identical bearings subjected to identical usage applications and environments will attain (or surpass) before bearing material fails from fatigue. The bearing’s calculated L-10 life is primarily a function of the load supported by (and/or applied to) the bearing and its operating speed. Many factors have a profound affect on the actual life of the bearing. Some of these factors are: • Temperature • Lubrication • Improper care in mounting resulting in: • Contamination • Misalignment • Deformation As a result of these factors, an estimated 95% of all failures are classified as premature bearing failures.
The Butterfly Effect • An event as small as a butterfly flapping its wings in Texas could set off a chain reaction of events culminating in a snow storm in Tibet.” • …extraordinary results can stem from attention to the smallest details.