Bearings are probably the more complex designed component of any rotating equipment; yet, they are the most misunderstood by the maintenance practitioners who handle them on a daily basis.” —Holcombe Baird, Reliability Center, Inc.
If experiencing premature bearing failures, you should not only look at bearing lubrication practices but also at bearing installation practices. When using an induction heater it is important to make sure that the heating is steady and even; fast is not always good, especially if you do not know what is happening with the temperature of the OD of your bearing. Remember that the inner race heats faster than the outer race. Precision bearings are prime candidates.
In the picture above, on the left you see a single temperature probe, placed on the ID of the bearing, and by the time the temperature of the ID reaches 110° C, the temperature of the OD is only 60° C. This could be a huge problem if the clearance between the ball or roller bearings and the raceways of the ID and OD is not enough to handle the temperature difference. In these cases the bearing balls or rollers get squeezed between the OD and ID damaging the bearing before it is even installed.
Read my entire article at Reliable Plant
Many thanks to Rick Trichka with TM Induction Heating and to Robert “Bob” Latino and Holcome Baird at Reliability Center, Inc. for their input.
by Ana Maria Delgado, CRL
It seems that every maintenance department has at least one Hercules that uses more muscle than technique to complete maintenance activities. Brute force and strength are occasionally required to complete a task. Having Hercules around is important when those moments arise.
However, applying care and good technique are usually better. Over 90% of rotating equipment has defects at startup that result in equipment failure. One of the reasons arises from making bearing installation a herculean task and not using proper technique. Excessive force applied during bearing installation can introduce defects that lead to premature equipment failure. Instead of beating the bearing on with a sledge hammer, gently heat it up on an induction heater, automatically demagnetize it, and then slip it on. If Hercules did the job, then the bearing and equipment are doomed to failure from the moment of startup. This results in increased maintenance cost, increased risks, increased equipment downtime.
Installing equipment bearings should not be a herculean task. Instead, proper technique and best practice should be applied to correctly install bearings. Induction bearing heaters like SURETHERM can help eliminate induced bearing defects due to poor fitting and improper mounting techniques. Induction bearing heaters provide increased safety, increased efficiency and reduce the risk of bearing contamination and damage that can result from using brute strength, oil baths, blow torches or other improper methods to heat bearings for proper installation.
by Trent Phillips
During the recent AFPM Reliability & Maintenance Conference and Exhibition in Orlando, FL. Terry O’Hanlon, Publisher of Uptime Magazine and Reliabilityweb.com, gave a speech about proper maintenance practices. One of the subjects was ‘Proper Mounting of Bearings’.
In the late 1960’s, one of the large cotton seed processors in Nicaragua had an urgent need for a replacement bearing made by Timken for their oil extraction units.
Not only did I sell them the not readily available industrial bearing from Timken, I also offered them a FAG Induction Heater for Bearing and/or a DAKE hydraulic press (both products for which we had the representation for Nicaragua) for proper mounting of the expensive bearings. The customer didn’t care for anything else but the bearing. Improper mounting procedure damaged the new cup and cone bearing before it underwent the first revolution on the shaft. The result was a repeat order for another bearing, however this time with a hydraulic press from DAKE.
The revolution in Nicaragua in 1979 brought me to the USA. Again I am selling Bearing Heaters among other maintenance related tools for predictive and corrective procedures. Unfortunately, it is no easier to sell products that keep manufacturing plants running efficiently in an industrialized country like the USA than in a country of the Third World.
Some use Induction Heaters for Bearings with an electronic temperature probe, others use so called Tempsticks which melt at a certain temperature and thus indicate that the bearing is ready to be mounted while others wait until the grease of the bearing starts to evaporate creating a certain smell which for them is a sign that the proper temperature has been reached. Bearings should never be heated beyond 120 degrees Centigrade (250° F) because otherwise it starts to change the metallurgical structure of the bearing.
Not only bearings should be properly heated. Gears, crane wheels and other industrial components are heat-treated in costly processes which easily go to waste due to unprofessional procedures like using a blowtorch resulting in uncontrollable and uneven heating.
As long as maintenance processes are not brought up to modern standards, and as long as Maintenance Departments in every single industry in our country are not given their due status, and as long as Production and Maintenance don’t act in unison, will we not be able to regain dominance in production.
by Dieter Seidenthal