Archive for the ‘Lubricants’ Category

What Are Zerk Fittings Or Grease Fittings?

Friday, May 20th, 2016

Zerk fittings are also known as grease fittings, grease nipples, or Alemite fittings. A Zerk fitting is a small metal fitting used in many mechanical systems for the purpose of feeding lubricants such as grease.

The grease is fed into the bearing or mechanical system under moderate or high-pressure with the use of a grease gun.

Zerk fittings are permanently installed into the bearing by a threaded connection. A nipple connection is left for the purpose of attaching a grease gun to feed lubricants into the bearing when required.

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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.

Lubrication FAQ

Friday, May 29th, 2015

Lubrication helps reduce bearing friction, transfer heat, and protect bearings from corrosion. This allows bearings to have a maximized life span, and perform optimally day-to-day. For such a simple idea, there sure is a lot to know about proper lubrication techniques. Manufacturers continue to create specialized lubricants and lubricators for various different applications. Follow the tracks through this lubrication FAQ for guidance.

What’s elements make a good all-purpose industrial grease?

You’ll want to look for a lubricant that protects against rust, corrosion, and general wear. For industrial bearings which operate at higher temperatures, look for assurance that the product is made for operating temperatures up to 300° F and “extreme pressure”.

An all-purpose lubricant with these characteristics will be well-suited for most industrial applications, such as: wheel bearings, axles, ball joints, U-joints, power takeoffs, off-road applications, and bushings.

What about synthetic lubrication for industrial applications?

Take a look at our previous post about synthetic lubricants here. In some instances, synthetic greases are superior to petroleum-based oils in their ability to resist breakdown from mechanical and thermal conditions.

Synthetic lubricants can provide the same bearing protection as natural greases. They can be formulated to endure high-pressure applications, inhibit corrosion, and prevent wear and oxidation. Designed for a variety of industrial, agriculture, and construction applications, synthetic lubricant can be especially well-suited for press-section bearings and calendar bearings.

Before using synthetic oil grease for your application, contact your sales or service engineer to be sure it is acceptable.

Is there lubrication specific to the food industry?

Food-safe lubrication is manufactured for food processing environments where there is a possibility of incidental food contact. You’ll want to be sure the lubrication you choose was formulated in compliance with CFR Title 21 Section 178.3570 and meets the requirements set by NSF H1.

Look for characteristics such as “food-safe”, “anti-wear” and “inhibits corrosion and oxidation” for long-life and optimal performance. This type of lubrication is best for food and beverage industry applications, as well as pharmaceutical industry applications.

When should I choose a lubricant with EP, or extreme pressure additives?

If your application will cause high axial or thrust loads, EP additives will be beneficial for you. If used in situations where there is not a high axial or thrust load, fatigue life of the bearing life may be reduced.

How do I clean out the lubricant from my bearing?

Wipe off all the lubrication you can reasonably reach. Then, wipe all surfaces with hydrocarbon solvent. This could be mineral spirits or kerosene. End with an isopropyl alcohol wipe. This process will work for both mineral and synthetic oils and greases.

If there is oil separation in my grease can I still use it?

Yes. Grease lubricants are formulated to release oil to be effective. Lighter grade grease will be more prone to oil bleeding. When compared with the amount of grease in the container, the amount of oil separation is normally insignificant, and can be safely stirred back into the rest of the grease prior to use. To prevent oil separation, keep storage temperatures consistent.

Why has the color of my lubricant darkened? Is it still OK to use?

Yes, it’s OK to use. Additives sometimes darken when exposed to sunlight, UV light, air and temperature changes. This is a result of the oxidation of those additives, but since they typically make up a small portion of the overall formula, there would not likely be any functional change.

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.

Lubrication Methods for Roller Bearings

Friday, January 30th, 2015

For rolling bearings to operate properly, they must be effectively lubricated to prevent metal to metal contact of the rolling elements, raceways, and cages. Thus, the primary function of adding lubricant is to separate these surfaces.

The lubricant also will protect the bearing’s surfaces against corrosion. Along with its other functions, a lubricant may also provide sealing against contaminants, or act as a heat transfer medium. It is important to choose a well-suited lubrication for each bearing application.

Operating conditions will determine the correct choice of lubricant, i.e. temperature range, speeds, and surroundings. Note that because the lubricant in a bearing arrangement loses its properties as a result of working, aging, and the build-up of contaminants, it will need to be changed and renewed at regular intervals for proper bearing function. This is called “relubrication”.

Oil is generally used for rolling bearing lubrication when there are rather high speeds, high temperatures, or when heat has to be removed from the bearing position. The most important property of lubricating oil is its viscosity. The lubricant’s viscosity is directly related to the amount of film thickness it can generate, which is the most critical component to achieving separation of the bearing’s rolling and sliding surfaces.

Mineral oils are typically favored for rolling bearing lubrication, with rust and oxidation inhibitors as additives. Synthetic oils can be considered for lubrication in extreme cases such as very low or very high operating temperatures.

Methods of oil lubrication for roller bearings:

Oil bath: Can be used for low to moderate speeds. The oil stays in a pool at the bottom of the bearing, and as the bearing rotates, the oil is distributed and then flows back to the oil bath at the base.

Oil pick-up ring: For bearings operating at higher speeds and temperatures, the pick-up ring circulates oil by hanging loosely to the shaft and rotating with it to transport oil. The oil then flows through the bearing back into the reservoir at the base.

Circulating systems: This method is preferred for high speed operations. With the aid of a pump, oil is circulated to the bearing, drains and returns to the reservoir where it is then filtered and cooled before returning to the bearing.

Oil jet: For very high speed applications, where a jet of oil under high pressure is directed at the side of the bearing. For this, the oil jet’s velocity must be high enough to break through the turbulence surrounding the rotating bearing.

Oil mist: Used today only in unique conditions, oil and air under suitable pressure are supplied to the bearing housing.

Oil spot method: Uses compressed air to transport lubricant directly to the bearing. The oil is sent into the airstream supply lines to the bearing housing at set time intervals.

When to Use Synthetic Lubricant

Friday, January 9th, 2015

It isn’t always clear which lubricant to choose, especially since the introduction of synthetics into the market. There are many questions when it comes to when to use a synthetic lubricant. Although it would be difficult to answer for every possible scenario, the following information should prove useful for you when selecting the right lubricant for the job.

Naturally occurring lubricants, or mineral oils, contain organic compounds of oxygen, sulfur and nitrogen. These compounds are problematic, because they enable oxidation and acid development. Then there is the issue of the formation of sludge, particularly in high-temperature applications.

The varying molecules in mineral oils also have differing shapes, which results – at the molecular level – in irregular lubricant surfaces. Irregularities generate friction within the fluid itself, increasing power requirements and reducing efficiency.

In contrast, the components of synthetic lubricants are high in purity with strong molecular bonds. The end product is a pure compound, less vulnerable to oxidation, more resistant to breakdown, and of a uniform molecular size. Therefore, their protective characteristics are more predictable.

There is a broad selection of synthetic lubricants, ranging in viscosities and consistencies, and even “green” environmentally friendly varieties. And they are generally affordable compared with conventional petroleum-based lubricants.

Synthetic grease costs haven’t risen as rapidly as conventional greases, thus reducing the cost differential between the two categories. This is largely due to stricter environmental and worker safety requirements in the industry.

The difference between conventional and synthetic greases can be found in the lubricating agent. Petroleum-based greases involve mineral oil, for example, whereas synthetics employ silicone or other engineered chemical compounds.

Synthetic lubricants have long been considered the right choice for applications involving extreme temperatures, loads and speeds.

The upper temperature limit for conventional greases is approximately 285 degrees F. In this range, synthetic greases exhibit better mechanical stability. Conversely, synthetic greases also excel at lower temperatures, where conventional greases may become stiff and lose effectiveness which can prevent bearings from properly rotating.

It appears that synthetics are superior for usage in the extreme zone where temperatures, high loads or flammability are concerning variables.

There is still much debate over whether or not it is in the best interest to use synthetic lubricants over conventional ones 100% of the time. It is best to research for the specific application you are needing the lubricant for, before deciding for yourself.