Posts Tagged ‘lubrication’

Overview of the SKF Bearing Company

Friday, September 8th, 2017

SKF, short for Svenska Kullagerfabriken, is one of the world’s leading seal and bearing manufacturing businesses. It was first founded in 1907 in Gothenburg, Sweden.

This company supplies and manufactures power-transmission products, mechatronics products, maintenance products, condition-monitoring systems, lubrication as well as lubrication systems, seals, bearings and related services on a global level in 130 countries.

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How Do Rolling-Element Bearings Work?

Friday, July 1st, 2016

Rolling element bearings are probably the most common machinery component in any industry. They are in everything from gearboxes to electric motors to conveyor systems.

If a shaft should spin, it usually does it while supported by a rolling element bearing system. The specific makeup of the device depends on the application, however.

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Ball Bearing Problems And Avoidance

Friday, April 29th, 2016

The accurate diagnosis of ball bearing failure is important to prevent repeat failures and additional expenses.

Ball bearings are found in a vast majority of machinery applications today. These bearings are quite reliable even under the toughest of conditions. They have quite a substantial service life under normal operating conditions.

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Bearing Questions and Answers

Friday, October 2nd, 2015

In the bearings applications we discuss on this blog, few are clean and sparkly, and make storage, installation, lubrication, and maintenance easy as pie. In other words, we all have questions about how to properly care for the bearings we use, that are beyond the manual. Today, we’re going through some frequently asked questions and offering some bite-sized answers for you.

Q & A

Q: If you have a new bearing that has been used, but is pretty dirty, what can you do to use it again?
A: Hand wash, and try not to spin it. Never wash double shield bearings, only wipe them off then apply lubricant before wrapping and storing.

Q: Besides storing bearings on the shelf, what’s the “correct” way to store them?
A: Keep bearings in a clean, dry location, and watch temperature changes as drastic changes can harm the bearing if any moisture is present. Handle bearings as little as possible, as your fingerprints can promote rusting. Take care not to drop or handle them roughly, they are precision components. Another best practice is to store them by keeping the oldest at the front, and always using the oldest bearing first.

Q: I understand lubrication is essential, but what is its main role?
A: Lubricant is used to establish and maintain a micro-thick separating film between rotating and static parts, so that the bearing can perform well, have long life, and keep from being damaged.

Q: Is getting the correct type of lubricant really important?
A: Yes, improper lubrication is responsible for approximately 43% of bearing failure – that’s a lot! Application specific grease or oil is important, as is lubricating frequency, quantity, and viscosity. Be sure to re-lube at proper intervals, and beware lubricant contamination. And, take note that over-lubrication of bearings used in high heat applications can be just as harmful as insufficient lubrication.

Q: Can seals be used in place of shields on a ball bearing?
A: Not if you want to avoid problems. A shield provides a clearance between the inner and outer race, whereas a seal is attached to the inner race and could cause problems rubbing on the inner race, depending on the speed, heat, and starting torque of the machine.

Q: How can I determine if a bearing is failing?
A: Three main indicators – excessive noise, heat, and/or vibration. If these are present more than expected, you can be pretty certain that a bearings is failing.

Q: Are there any common improper methods of mounting or installation?
A: A couple main ones here. One is contaminating the bearing during installation. The other is applying force on the incorrect ring, as it should only be applied to the press fitted ring.

Q: If my work space is dirty, how can I take care to install a new bearing without messing it up from the git-go? 
A: It’s understandable, after you’ve taken the time and care to properly store your bearings, that you would want to be sure to install them in a clean environment. But, that’s tricky. Clean the work bench area and the tools you will use on the new bearing, and keep away any linty cloths. Keep the bearing on its original wrapper or some clean paper when working on it. Don’t let the bearing sit on a dirty surface, even for a short time, or you’ll risk contamination and early failure. And, remember bearings shouldn’t be washed, except for oil mist or circulating oil system.

Q: Will a stainless steel bearing protect against rust?
A: Not to the extent you might think. Stainless steel is not rust proof. It is corrosion resistant and will rust in corrosive environments over time, but at a much slower rate than chrome alloy steel.

Q: What is a good waterproof seal?
A: Bearing seals are designed to retain the lubrication inside the bearing, and most are considered water-repellent, but they won’t prevent water from entering the bearing if it is submerged. If the bearing must operate while submerged in a liquid, use a ceramic hybrid or full ceramic bearing.

Q: What does “radial play” mean?
A: Radial Play refers to the fit or clearance of the balls within the bearing. The normal range is from C2 to C5, with C2 being the tightest fit (not much room for expansion of the balls or misalignment) and C5 being the loosest (allowance for some expansion as the bearing heats up or misalignment of the application).

Q: Can I flush out a lubricant and use another?
A: You would need a prescribed flushing agent, and a properly environmentally controlled environment in a controlled area. The bearing would have to be thoroughly dried post flush, and lubricated with the correct amount and type of grease. Short answer is yes, with some extra effort.

Remember, if you do the best you can, all these efforts will prolong bearing life and improve machine performance.

3 Main Reasons for Lubrication Failure

Friday, September 11th, 2015

It’s been around for thousands of years. We’ve used it since the dawn of the wheel. So, why does lubrication still seem to be a major issue in industries today?

Well, there’s not exactly a simple answer to that question. The short answer is – it’s complicated.

Really! Technologies have improved and expanded to major levels we never even thought possible 100 years ago.

Nowadays, there are so many different moving parts, new materials we aren’t familiar working with, and so much more to keep track of, including proper lubrication for all those parts.

Today, we’ll go through 3 main areas where lubricant failures occur.

Moisture

This is another common failure mode seen. It is a result of excess moisture entering the lubricant, due to rain, humidity, human error, or other equipment errors.

Equipment errors include improper seals and wash down practices. Human error in this case includes improper storage methods such as lack of ventilation.

The tiniest bit of moisture in oil lubricant can reduce its lifespan by half. The less moisture in your oil lubricant, the better your equipment will perform and the less chance of failures.

Additives, which control oxidation, are also important in extending the lifespan of lubricants. These will deplete over time though, especially if other factors are increasing the moisture in the lubricant. Fix this by maintaining strong additive levels.

To keep moisture failure away, do what you can to reduce moisture levels in new lubricants, as well as eliminating moisture in stored lubricants, equipment, and wash down procedures.

Temperature

This can be caused by limited air movement, lubricant overload (main cause), incorrect cooling levels, an even using a high viscosity lubrication or the wrong viscosity.

Temperature failure happens because higher temperatures result in faster oxidation. This ultimately leads to more component wear.

Although most lubricants have a long lifespan of about 30 years, rises in temperature will majorly decrease their lifespan. Lubricants need to be kept at 70 degrees Fahrenheit. If this temperature is raised by 20 degrees, it will cut the lubricant’s lifespan in half.

Say the operating temperature for the lubricant application you have is 170 degrees, then this lubricant needs to be replaced at least once a year, twice to be on the “safe side”.

You can reduce the risk of temperature failure by using coolant, and changing it more often. Also, consider using synthetics, since they are better able to hold up to high temperatures.

Contaminants

There are several ways contaminants can enter lube. Depending on how it is stored, transported, and filtered, foreign materials are likely to get in with improper handling practices.

It is harmful to machinery if there is a large amount of foreign particles in the lube. There is only a very small amount of room for lube between a bearing or gear. If foreign particles are present, they can grid and scratch the machine’s gears.

The ISO’s (International Organization for Standardization) code for cleanliness gives us a means of knowing how many foreign particles are in the lube we purchase.

The code comes in three numbers, each determining how much contaminants of different sizes (4, 6, and 14 micron particles) are in a one millimeter sample of lube.

Depending on the level of reduction, these life extensions can get up to seven or eight times.

Working to eliminate particles from lubricants by filtering, watching for cleanliness before and during equipment use, and/or using synthetics can more than double the lifespan of a machine.

It may seem tedious or tiring to remember to take extra good care of lubrication, but it’s well worth the effort. As much as 60-80% of bearing failures (catastrophic, functional, & premature) are lubrication-related.

Guide to Timken Greases

Friday, February 13th, 2015

Bearings need lubrication to help reduce friction, transfer heat and protect from corrosion.

The Timken Company, a global leader in bearing and steel technology, also understands the importance of lubrication and friction management. Timken lubricants help bearings and related components operate effectively in demanding industrial operations. They also offer additives for high-temperature, anti-wear and water-resistance, which help to give superior protection in difficult environments. You can turn to Timken for a single source and a variety of lubrication options.

This post will spotlight 7 different Timken grease products, to give you more of an idea about what applications they can help you with.

Timken Premium All Purpose Industrial LC-2 Grease:
Environment – High-wear, moderate loads, moderate speeds, and moderate temperatures.
Application – Agriculture, bushings/ball joints, truck and auto wheel bearings, heavy duty industrial.

Timken Construction and Off-Highway Grease:
Environment – Extreme heat, heavy loads, high sliding wear, dirty environments, slow speeds, shock loading.
Application – Ag/mining, cement plants, construction/off road, rock quarry, earth moving equipment, fleet equipment, heavy industry, pivot pins/splined shafts

Timken Ball Bearing Pillow Block Grease:
Environment – Wet and corrosive conditions, quiet environments, light loads, moderate to high speeds, and moderate temperatures.
Application – Lightly loaded pillow blocks, idler pulleys, oven conveyors, electric motors, fans, and pumps.

Timken Mill Grease:
Environment – Corrosive media, extreme heat, heavy loads, wet conditions, slow to moderate speeds.
Application – Aluminum mills, paper mills, steel mills, offshore rigs, power generation.

Timken Food Safe Grease:
Environment – Incidental food contact, hot/cold temperatures, moderate to high speeds, medium loads.
Application – Food and beverage industries, pharmaceuticals.

Timken Synthetic Industrial LC-1.5 Grease:
Environment – Extreme low/high temperatures, severe loads, corrosive media, slow to moderate speeds.
Application – Wind energy main bearing, pulp and paper machines, general heavy industry, marine applications, centralized grease systems.

Timken Multi-Use Lithium EP1/EP2 Grease:
Environment – Moderate speeds, light to moderate loads, moderate temperatures, moderate water.
Application – General industrial, pins and bushings, track rollers, water pumps, plain and antifriction bearings.

The History of Lubricants

Friday, November 28th, 2014

Imagine what a pat on the back that smart fellow received when he discovered that applying animal fat to the wheels of chariots made them run more easily. I’ll bet he earned a day off for that one!

We’ve come a long ways since those primitive discoveries of using lubricants. Kathryn Carnes, features editor over at The Society of Tribologists and Lubrication Engineers took a look at the most critical moments in tribology’s history (the study of interacting surfaces in relative motion – i.e. friction, lubrication, and wear).

I’d like to share a few with you on the subject of lubrication in this brief history lesson.

As you might think, evidence of lubricants being used begins in ancient Egypt.

Many illustrations were left by the Egyptians showing large objects and stones being pulled across flat ground, or wooden planks. This was possible when people would pour down liquids before the object, so as to lubricate the surface area. For many tasks, olive oil was the lubricant of choice.

It’s been documented that the Egyptians also used pitch, which is a solid form of petroleum, for mummification. There are also biblical accounts of pitch being used by Noah as he built the ark.

By the 1600s, settlers in Pennsylvania were witnessing the native people’s collection of crude oil that had found its way up to the Earth’s surface. It was collected and used as fuel and medicine.

“To this day (and likely for many years to come) the influence and scope of petroleum lubes is unparalleled”, noted Kathryn.

Theories on hydrodynamic lubrication popped up between 1883 and 1905, when research showed that adding a fluid film would separate the surfaces of machinery, preventing wear and reducing friction. The increased pressure forces the surfaces apart, creating what’s called hydrodynamic lift.

Thanks to this discovery, we have slider bearings and journal bearings, both heavily used in machinery and vehicles.

The quest for synthetic alternatives began in 1877, when French chemist Charles Friedel and American James Mason Crafts developed the first synthetic hydrocarbons. It wasn’t until 1929 though, that commercial development of synthetic hydrocarbons occurred, by the Standard Oil of Indiana.

During the 1930s and early 1940s in Germany, synthetic fuels, rubber, lubricants and waxes would emerge on the market.

For those cases where liquid lubrication would not suffice, interest in self-lubricating materials was strong in the 1940s. The most famous of these was the discovery of PTFE (or Teflon) by Dr. Roy J. Plunkett in 1938. He came to this discovery in the midst of testing tetrafluoroethylene as a refrigerant.

That brings us to the discovery and application of elastohydrodynamic lubrication (EHD). In EHD, pressures are high and lubricant viscosity rises, assisting in the formation of an effective film.

Understanding EHD has led to the development of rolling element bearings, an invention which has allowed us to operate machinery and vehicles at a wide variety of speeds and loads, with very low friction or wear.

I hope you’ve enjoyed this look at how things were done in the past, and how they’ve led us to where we are today. I can only imagine where we will be in ten more years, or one hundred.

Original article from The Society of Tribologists and Lubrication Engineers can be found here.