3 Product Innovations You Should
Some bearings are specifically designed to save time and cost in challenging applications.
By The Timken Company
Many plant technicians are familiar with routine bearing maintenance, including installation, removal, and re-greasing of critical machine bearings. These tasks can be time-consumingdepending on the type of equipment, bearing location, andmethods used; in all cases, speeding up the job is a priorityfor MRO personnel responsible for ensuring a smooth, reliable operation.
Bearing makers heard these concerns and have responded with bearings that are easier to adjust, use fewer toolsor require less frequent relubrication. The goal is always thesame—saving hours (even days at a time) to avoid costlydisruptions throughout a facility.
Among today’s popular bearing designs are some less-er-known configurations that can also relieve the burdenfelt by busy maintenance staff. If lost productivity is a recurring problem, consider stronger bearing solutions andinnovative approaches such as these:
1. SHAFT-GUARDING TECHNOLOGY
Conventional housed bearing units (also called mountedbearings) tend to use setscrews or a similar-type locking device that can cause galling or seizing, leading to shaft repairand increased downtime for bearing removal.
Bearings with shaft-guarding technology have two setscrews that do not dig into the shaft in order to maintaingrip, thus avoiding life-shortening damage due to gougingand fretting. As the setscrews are tightened, a hardenedstainless steel band under the screws is compressed, lockingthe bearing to the shaft while eliminating any risk of damage from the screws. Other design features tend to include agroove running beneath the setscrews in the bearing innerring bore that serves to locate the band, while the extendedlength of the inner ring can also provide extra stability toimprove shaft support and reduce bearing misalignment.
Shaft-guarding technology can be a wise investment anywhere shaft replacement is particularly difficult and expensive. Applications tend to include fans and blowers, conveyors, presses, and other general industrial equipment.
To understand the impact such bearings can have, consider the example of a typical plant operating 50 pieces ofsimilar equipment, each using two ball bearing housed unitsper shaft. Based on a 30-year equipment life cycle, two-yearbearing life, and six-year shaft life (equaling 14 bearing replacements and four-shaft replacements over the life of asingle piece of equipment), savings could amount to over
$4,000 annually across the plant—and more than $120,000
2. SPLIT-TO-SHAFT HOUSED UNITS
over the life of all equipment—due to the reduction in the
number of bearing and shaft replacements (based on stan-
dard U.S. labor rates, typical unit costs and the typical num-
ber of hours for repair and replacement of bearings and
shafts). Furthermore, the plant could gain up to 525 addi-
tional hours of uptime over the life of the equipment due to
faster-housed unit replacement on all shafts.
Often, the problems encountered with bearings are notperformance-related; more likely they are related to lossesin time and expense as a result of the teardown and reassembly operations required to access hard-to-reach bearings. When a housed unit is buried deep inside a machine,it can take days to disassemble the equipment, remove theshaft, service the bearing and reinstall the shaft before resuming operations. Even where housed units are easily accessible, shaft removal or lifting of the shaft and ancillaryequipment is often necessary to change bearings.
Split cylindrical roller bearing housed units are the industry’s answer to bearings trapped in high-service-cost locations. These units feature removable housing halves, support caps, and bearing components that make it simple tovisually inspect or replace bearings in a fraction of the timecompared to conventional solid block units.
By eliminating the need to remove the shaft to access thebearing, a split-housing design can reduce installation timesignificantly as opposed to servicing trapped SN/SD/SAFsolid housings. In nearly all cases, a split configuration canmean a lower cost of ownership over the life of the bearing.
Some split-to-shaft units also employ an angled cast ironsupport, or pedestal, to allow mounting in locations withlow clearance between the base and the center of the shaft.This design feature eliminates the need to raise the shaftto allow clearance for the pedestal yet maintains standardbearing and housing construction requirements.
For those looking for an easier way, a split bearing unitcan reduce the total cost of ownership compared to housingswith solid, non-split bearings. These units are favored for awide range of applications, including equipment commonlyfound in cement, chemical, food processing, and pulp andpaper plants, as well as for mining, power generation, andoil and gas operations.
3. SOLID LUBE
Providing proper lubrication to bearings is an essentialpractice in helping to ensure they will reach their targetedservice life. The process can be messy and laborious, however, and in many industrial facilities, there is good reasonto avoid greases wherever possible, particularly in food andbeverage plants where machines operate in close contactwith edible goods.
There is growing interest in target industries for Polymer
Solid Lube (PSL) bearings that are a grease-free alternative
to traditional bearings requiring periodic relubrication. PSL
is a microporous polymer structure impregnated with oil
that entirely fills the free volume in the bearing between the
races, rolling elements, and cage. During bearing rotation,
the polymer solid lubricant releases the appropriate amount
of oil to lubricate the rolling elements and raceways.
By filling the bearing, PSL also creates an extra line of defense against debris ingress (together, the lube and bearingseals help keep contaminants out). Material and maintenance savings as a result of never having to re-grease critical bearings can be significant, and this is compelling moreplant operators to investigate the advantages of PSL bearings that are also finding a place in aerospace, off-highway,and metal processing applications to name a few.
Bearings have moved our world for over a century, andwhile it may seem there is little room left for improvements,the reality is that innovation continues today as bearingmakers are not done finding new ways to save their customers time and money. Talk to your trusted adviser about minimizing bearing maintenance with the latest solutions builtspecifically for industrial needs.
THE TIMKEN COMPANY engineers, manufactures, and markets bearings, gear drives, automated lubrication systems,belts, chain, couplings and related products, and offers a spectrum of powertrain rebuild and repair services. The leading authority on tapered roller bearings, Timken today applies its deepknowledge of metallurgy, tribology and power transmissionacross a variety of bearings and related systems to improve thereliability and efficiency of machinery and equipment all aroundthe world. The company’s growing product and services portfolio features many strong industrial brands including Timken,Fafnir, Philadelphia Gear, Groeneveld, Drives, and Lovejoy.
For more, visit newequipment.com/21125779
Setscrew shaft damage is common—some bearings are designed to prevent theproblem completely. The Timken Company