How important can the right lubricant be to your company’s bottom line? More than you might think. Because lubricants typically make up only one percent of a company’s total operating costs, many lubrication programs do not receive the attention they deserve. However, the surprising truth is that the lubricants a company chooses can have a significant impact on high-visibility and high-value line items such as energy, labour and equipment costs.

Price versus cost
Identifying the true cost of your lubricant program is the first step in optimizing your plan to positively impact your bottom line. When analyzing your current lubrication program consider how much lubricant you’re using, how often you relubricate, and how much time that relubrication takes. If you already have a handle on these numbers you’re well ahead of the game. If you don’t, take some time to establish a baseline so that when considering alternative products you can conduct an “apples to apples” comparison. By tracking these variables you will come to realize that the true cost of your program includes much more than the price per kilo or price per liter of your lubricants.

Now that you have a firm grasp on the true cost of your company’s lubrication program, the next step is to evaluate where savings are possible. Let’s take a more in-depth look at the factors involved.

Increased productivity
Facilities are constantly pushed to increase productivity while reducing maintenance and operating expenses. Any time your equipment is idle, you’re losing productivity. While some maintenance, including lubrication, can be completed while your line is in operation, some has to be conducted during downtime. This is not a huge inconvenience if you have regularly scheduled downtime that coincides with your relubrication schedule. However, if you have to bring a machine down once a shift specifically to relubricate, that’s money taken away from the bottom line every shift. What if you were using a lubricant that extended that relubrication interval to once a month?

Reducing maintenance costs
If your plant is like most, there is probably a wish list of maintenance projects just waiting for the manpower and time to get them done. While even the best lubricant can’t create time, an optimized lubrication program can help free-up resources to accomplish those tasks. If your lubrication specialist is able to extend relubrication intervals through the use of synthetic, newer-generation products, you can do more with the same staff and with the same time. In our case study, the facility had the potential of reallocating almost 1,500 man-hours annually.

Used-lubricant disposal is also a variable in calculating the costs of your lubrication program. Extended lubrication intervals impact these figures. If you’re using less lubricant, you’re disposing of less lubricant — another savings to the bottom line. And don’t forget your spare parts inventory. Proper lubrication can help your machinery and its components last longer which means less money spent on repairs or rebuilds. Your equipment is a major investment and should be maintained accordingly.

Another factor to consider is how much energy a company can save by utilizing highly efficient gear oils. The right lubricant can reduce the coefficient of friction resulting in less power loss. In other words, the right lubricant requires less energy, leaving you with a lower energy bill at the end of the month.

Lubricants on your line affect your bottom line
In order to avoid the pitfalls of purchasing lubricants based solely on price, evaluate your current program and then request a comparative cost benefit analysis from a supplier. Simple calculations can reveal significant savings that aren’t always evident in the initial cost of a lubricant.  n

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Kimberly Eldridge is a North American market manager with Klüber Lubrication. For more information, visit www.klueber.com.

Bearings are critical components of machines and with proper performance monitoring, imminent failures can be identified and corrected. However, without a monitoring program in place, and subsequent corrective actions taken, a single bearing failure can result in full machine shutdown and countless hours of lost production.

Bearing monitoring is guided by three main senses: sight, sound and touch. Basic monitoring is conducted through elemental observations. However, many highly sensitive tools are available that amplify these observations so they are more noticeable, recordable, and include basic logic to assist with warning identification.

Visual Monitoring
Monitoring bearings visually through classical methods include observing lubricant condition, corrosion, and deterioration. Mounted bearings that are lubricated properly will purge grease from their seals. The condition of the grease upon purging can indicate improper relubrication intervals and/or contamination. Dark, cakey or milky grease are visual signs that relubrication intervals and procedures may be improved.

Evidence of corrosion is a valuable monitoring tool as well. High levels of corrosion can degrade material strength and performance. Deterioration of the surface, seals, or obvious physical dimensional characteristics should also warrant further investigation. These observations are often signals of wear, heat and other abnormal performance prior to total bearing failure.

Several monitoring tools commonly available to leverage visual observations include site gauges for oil lubricated bearings, and thermal imaging guns. Bearings that are lubricated by oil rather than grease are often fitted with site gauges, which will give an indication of the presence of oil and the quantity of oil available to the bearing. These gauges are practical and inexpensive.

Audible Monitoring
Traditionally, audible monitoring is one of the most common methods of monitoring machinery because odd noises are obvious indicators of improper operation, even to the untrained user. It is conducted quickly through an operator’s daily routines. After all, if a bearing within the machine doesn’t sound well it usually isn’t well.

The main problems with bystander audible observations is that (1) it usually identifies the later stages of bearing failure, when planning downtime for bearing replacement is impractical and (2) when audible feedback of a single bearing is masked by the overall noise of its environment. That’s when instruments such as stethoscopes (with amplification) and decibel level meters are advantageous. Both tools are available with a wide range of features that include quantified readings and recording features so bearing performance can be trended. These tools are also more useful at identifying improper operation at a less threatening stage of failure.

Bearings should run quiet and smooth; anything different will likely reflect a flaw or a problem with the bearing itself. Noises such as grinding or banging should be investigated quickly. These noises may indicate complete bearing failure and continued use may lead to catastrophic failure and/or damage to neighboring equipment. Bearing noises such as light clicking and squealing may indicate looseness, faults or skidding and should be inspected for cause and remedy.

Audible evaluation is not as sensitive as other monitoring techniques. It is primarily a method of identifying a failure more so than identifying poor performance. Additionally, audible monitoring in the early stages of failure is more noticeable at higher operating speeds than lower speeds.

Physical (Touch) Monitoring
Monitoring bearings by touch, and then trending the observations against historical performance is by far the most useful and accurate means for assessing bearing condition and predicting bearing failure. The touch method can be used to monitor temperature, vibration, and lubrication. 

Operating temperature is the most practical and beneficial monitoring method for bearings because expensive tools are not required and is appropriate to all types of applications; slow to high speeds, light to heavy loads. For example, the average threshold of pain for humans is approximately 130°F. If it is difficult to maintain hand-to-bearing contact for several seconds then the temperature is likely above 130°F. Furthermore, water droplets placed on a bearing housing that quickly boil will indicate that the bearing temperature will have easily exceeded 212°F.

There are also many useful tools available to measure and monitor bearing temperatures. The most common include thermocouples and resistance temperature detectors (RTDs), both of which can be permanently mounted to locations on the bearing housing for continuous real-time monitoring. Temperature switches are also available that can be utilized for warning and/or shutdown at dangerous operating temperatures. Many bearing manufacturers offer various permanently mounted sensors pre-installed in bearing housings in areas that will most accurately reflect the true bearing temperature, rather than the housing skin temperature.

Portable thermal imaging tools are also a quick and efficient means to monitor bearing performance. These tools use infrared thermography to visually identify variations in temperature over a broad area.  However, the most common portable temperature measurement tool is the infrared thermometer. Although it does not measure temperatures over a broad area, they are inexpensive and easy to use.

Monitoring and trending bearing temperature is important because as a bearing fails, the temperature will continually increase. Trending temperature over time will help identify a failing bearing in the early stages of failure.

Vibration analysis is the most information-rich method available for bearing analysis, and touch can help identify smooth versus rough operation. As safety permits, feel the housing during operation. Rough operation, jostling, or grinding may indicate a bearing problem.

You may also consider vibration measurement instruments to not only identify stages of bearing failure, but also identify overall machine performance and problems. Sensors mounted to the bearing may include permanently mounted or portable magnetic base accelerometers, displacement probes, or velocity pickups. Sensor selection is dependent upon the bearing speed, sensitivity requirements and the application. Although vibration feedback is highly beneficial, proper training is important due to the complexity in data collection and interpretation. 

Simple tests can also be conducted on purged grease to detect hard particle contaminants. Upon relubrication, rub some of the freshly purged grease between fingertips. Gritty grease may indicate a need to lubricate more often or wear from a failing bearing.

Many traditional and advanced options are available to monitor and evaluate bearing performance. Leveraging instrumentation to support traditional observations is a valuable practice in support of a predictive maintenance program.

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Galen Burdeshaw is Baldor’s customer order engineering manager for DODGE bearings and power transmission components. For more information, visit www.baldor.com.

Rolling bearings are high-precision machine elements whose service life directly determines the performance of machines. However, the actual service life is determined by many factors. Premature bearing failures cause costly equipment downtime, sometimes even with very serious consequences. Bearing experts provide some simple yet practical tips to optimize bearing performance.

Start with the right choice
Right from the very beginning, design engineers could enhance the bearing service life by selecting the right bearings for the application. Many factors — such as loads, rigidity, bearing life expectation, operating environment, etc. — need to be considered. Renowned bearing manufacturers have years of experience in different industrial applications. Developing bearing solutions with their assistance can contribute to optimal bearing and equipment service life.

Bearings from renowned manufacturers are produced with the latest technology and undergo stringent quality assurance procedures. Nevertheless, to guarantee the optimum bearing service life, special attention should be made in the following aspects: proper storage, careful mounting and dismounting, adequate lubrication and re-lubrication, appropriate condition monitoring, timely maintenance, and sound personnel training. 

Appropriate storage
In principal, all bearings should be stored in their original packaging until being mounted. They should be kept in a clean, non-humid environment at a fairly stable room temperature. Rolling bearings should be stored away from dust, water and aggressive chemicals. Vibrations and shocks could permanently damage the bearings mechanically and therefore must be avoided during handling and storage.

Basically all bearings must be stored flat. Particularly larger and thus heavier bearings might be deformed by their own weight if they are left standing vertically for a long period.

Special care should be taken for the storage of pre-greased (sealed or shielded) bearings. Such grease could change in consistence over a long storage period. This could raise the running noise to a certain extent when put in operation for the first time. Therefore the shelf life of such bearings should be controlled by an FIFO-system (First In First Out).
 
Cleanliness
Cleanliness is paramount when dealing with rolling bearings. The running surfaces and rolling elements usually have a surface finish roughness of tenths of microns (1/10 µm or 0.0001 mm). Such smooth surfaces are very sensitive to damages by contaminants. The lubrication layer between the running surfaces has usually a thickness between 0.2 to 1.0 µm. Impurities with particle size larger than the lubricants could get over rolled by the rolling elements and thus build up localized stresses in the bearing steel and eventually cause premature material fatigue. Normal environment dust has a grain size of up to 10 µm, which could already damage the bearings.

Therefore, a clean, dust-free environment is extremely important for bearing storage and mounting.

Thorough preparation for mounting
Bearings should be mounted and dismounted carefully by means of appropriate tools. Industry experts estimate that improper fitting causes 16 percent of all premature bearing failures.

For volume mounting in the production assembly the conditions are usually strictly controlled, and the suitable equipment is available for bearing installation. However, for maintenance or replacement work, the environments could vary. Therefore, thorough preparation for bearing fitting is necessary in order to ensure the optimum bearing service life. First of all, the relevant documentation, such as drawings, maintenance manuals, specifications, etc., should be carefully studied. All components, such as shafts, distance rings, housings, cups, flanges, etc., must be thoroughly cleaned and protected from contaminants. The conditions of such adjacent components should also be checked carefully.

Careful mounting and dismounting
Depending on the application, size and type of the bearing, an appropriate mounting method — mechanical, thermal or hydraulic — and tools should be selected. Here are some basic rules for bearing mounting:

Mounting forces should never be applied through rolling elements. This could easily lead to localized overloading in the contact area between the rolling elements and raceways which in turn causes premature bearing failures.

The bearing surfaces should never be hit directly with any hardened tools such as hammers, cotter pin drives, etc. This could cause a breakage or fragmenting of the bearing rings.

The instructions from the respective mounting equipment supplier should always be followed.

About 90 percent of rolling bearings are never removed from the equipment where they are built in. Usually only the larger bearings would be removed as part of the scheduled preventive maintenance programs. Same as mounting a bearing, dismounting should also be thoroughly prepared. During the dismounting, ensure the adjacent components such as the shaft or housing are not damaged. Appropriate methods and tools should be used for dismounting, depending on the bearing type, size and application.

Appropriate lubrication
The lubricant separates the metallic bearing surfaces such as rolling elements, rings, and cages and thereby reduces friction, preserves the metal parts and guards off contaminants and impurities. A wide range of lubricants — including grease, oil, and solid — is available for different operating conditions. The correct selection of lubricant is crucial to ensure optimal bearing and equipment service life.

Bearing lubricants undergo permanent mechanical stressing caused by the over-rolling of rolling elements. Moreover, lubricants change their chemical properties over time, particularly at high operating temperatures and in humid or polluted environments. All these lead to a gradual loss of lubricating quality.

Therefore bearings have to be re-lubricated at regular intervals to ensure maximum service life. The re-lubrication interval depends on operating conditions such as temperatures, running speeds, loads, environment, etc.

Only in case of pre-greased bearings (shielded or sealed bearings), i.e. “greased-for-life” bearings, the bearing service life is determined by the lubricant service life span.

Lubricants must be stored properly according to manufacturers’ instructions. Particular attention must be paid to keep the lubricant clean from any contamination. Prior to each application, the condition of the lubricant should be checked carefully.

Condition monitoring and maintenance
Generally rolling bearings are extremely reliable although they do not have an indefinite life. Like all other important components in the machinery, they should be inspected and maintained regularly. How often the inspections and maintenance should be carried out depends on the importance of the particular application and operating conditions of the individual equipment.

For bearing arrangements with critical functions, it is advisable to incorporate a condition monitoring feature at the design stage. Important parameters of the machine operation such as vibration and noise can be monitored continuously. Preventive measures could be planned before breakdowns.

Training
Practice makes perfect. But proper training provides the basis for the practice. Reputable bearing manufacturers offer various training programs for commercial, technical and workshop staff. Costly human errors can be avoided if maintenance technicians possess fundamental knowledge in handling bearings. Design and product development engineers can maximize the equipment performance and minimize life-cycle costs by optimal design of bearing locations.

Bearings are often critical components in all machines. Proper storage, careful mounting and dismounting, adequate lubrication and re-lubrication, appropriate condition monitoring, timely maintenance and, last but not least, sound personnel training are essential to improve bearing service life, and therefore enhance equipment performance.

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This is an edited article provided by NKE, which is distributed in Canada through Global Bear Inc. For more information, visit www.globalbear.ca.

Question: “We recently received a shipment of L10-rated bearings. Can you explain the meaning of the L10 designation?”

Rotating-element bearing manufacturers measure reliability using a “load–life” calculation rating known as the L10 rating life. To achieve this rating, the manufacturer assumes the bearing will be run in a clean operating environment that provides an adequate lubricant film (adequate described as a film equal to, or greater than, the composite roughness of the two mating surfaces) of the correct viscosity for the designed maximum bearing speed and operating temperature ratings.

The L10 rating is given to bearings manufactured with cleaner, degassed steels (usually manufactured in an electric arc style furnace) and represents a percentage probability that under ideal conditions 90 percent or more of all L10-rated bearings will achieve the published life expectancy.

As maintainers, we have great influence over whether a bearing will achieve its design life expectancy. The following points illustrate the basic dos and don’ts for ensuring a long and healthy bearing life:

• Store bearings in a clean, dry, temperature-controlled place in their original wrapping until required for use: This will eliminate contamination and ensure it is “factory fresh” when put into service

• Don’t handle bearings with bare hands when unwrapping and preparing for use: Always use clean gloves as debris from dirty hands will contaminate the bearing surfaces, and transferred sweat can cause the bearing to oxidize (rust).

• Check for factory lubrication: According to specification, some bearings come pre-lubricated while others do not. Ensure it is lubricated to approximately 40 percent of its open area, but do not over lubricate!

• Use recommended tools and techniques when installing bearings: Forcing one in place by hitting it with a blunt instrument is a recipe for premature failure.

• Establish a lubrication regimen according to load, speed, duty and environment: Lubricating it with the right lubricant, with the right amount, in the right place, at the right time, with the right contamination-avoidance practices will ensure it outlives its host. Establish a lubrication regimen according.

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Contact Ken Bannister at (519) 469-9173 or by email at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

For professionals dealing with highly specialised mechanical components like rolling bearings, a general technical understanding of the products can help them improve productivity and cut costs. Unfortunately, the “formal education” at technical schools hardly covers the practical skills needed for the industry. To fill this void, many leading bearing manufacturers offer specialised training courses.

Generally, any company dealing with bearings benefits from such training programs — optimised efficiency at workplace and motivated employees are just two of the direct results of appropriate training.

For machinery manufacturers, design and product development engineers can maximise equipment performance and minimize the life-cycle costs by optimal design of bearing locations. In one case, after acquiring adequate knowledge, a product design engineer could save 50 percent costs on one bearing location without sacrificing performance.

Equipment end-users can profit from bearing training too. According to experts, human errors are a major cause of equipment failures. Correct handling of bearings — such as storage, lubrication, and mounting/dismounting — not only ensures less bearing damage and longer bearing service life, but also results in lower maintenance costs, improved safety and more equipment uptime.

Not only engineers and technicians benefit from bearing knowledge. Commercial personnel such as sales and purchasing professionals can improve their job performance through bearing training. For example, a buyer can reduce costs by choosing a technically equivalent product variant for the application, or sourcing bearings from an alternative supplier with equal quality.

How to choose bearing training
First of all, the training needs and goals of a company should be identified. It has to be determined who should be trained in which fields. Next, the training has to be incorporated into the staff-training plan. The following factors should be considered when choosing a bearing training program:

• Reliable training provider: Reputable bearing manufacturers, such as NKE, offer well-organised training seminars to business partners.
• Curriculum design: Ask the training provider for a curriculum outline. You should find out whether the courses are targeted to your employees (commercial, technical or workshop personnel), as well as the breadth, depth and structure of the courses. If the standard modules do not completely suit your needs, ask for customised courses.
• Instruction methods: Usually bearing training is conducted in small classroom groups (maximum 10 to 15 people) for a dedicated learning environment and individual attention. Visual aids and handout notes should be provided. For practical topics such as bearing handling, hands-on exercises should be included.
• Instructors: The instructors should possess a combination of solid theoretical foundation and practical experience in bearing applications. They should be competent in knowledge sharing and training.

Learning does not stop when training is over. What has been taught in the classroom must be practised in the real world. Depending on programs, the trainees should show improved performance within days to months after the training. The post-training evaluation should be taken into consideration when planning for the next programs.

Training is an investment in productivity. It equips technical and commercial professionals with the essential knowledge to enhance their job performance. For the company, it means optimized product development, reduced procurement and maintenance costs, increased facility uptime, enhanced safety, employee loyalty and customer satisfaction. All these contribute to the long-term success of a business.

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This is an edited article provided by NKE. In Canada, NKE products are distributed through Global Bear Inc.

Question: “An analysis of bearing failures pinpointed contaminated lubricants as the primary cause. Could you provide tips for contamination avoidance?”


While not exhaustive, these tips will help keep your lubricants clean:

Storage
1) Always store lubricants in a dry warm place, protected from the elements.

2) If lubricants are stored outside, open to the elements, ensure they are protected from large temperature changes. (This can cause condensation in the container and create water contamination.)

3) If lubricant barrels are stored outside in the rain, store barrels horizontally in a rack system. If no rack is available, ensure the barrel is tilted slightly, with the “bung” positioned on the high side. This will ensure water does not pool on top, creating rust that can contaminate the lubricant once opened.

4) Never store opened containers without their correct lids installed tightly.


Oil Transfer
1) Always use dedicated transfer equipment. If you have five different oils in use, you will require five sets of transfer equipment identified for each lubricant (usually by colour).

2) If oil is to be transferred manually using a dedicated funnel and jug, only transfer the amount needed and use a simple coffee filter in the funnel to catch any contaminants.

3) Clean transfer equipment with a lint-free rag after every use and store it in plastic bags.

4) When using bulk containers, ensure lids are in place and that the container is kept clean (as oil is a magnet for dirt).

5) Ensure oil reservoirs are clearly marked or labelled to eliminate cross contamination.

6) Always reinstall reservoir fill caps and breathers.


Grease Transfer
1) When using manual grease guns, always clean the end of the gun and the receiving grease nipple with a clean lint-free rag before engaging the gun with the nipple.

2) Invest in a clear-reservoir-style gun to see what grease is inside and avoid cross contamination.

Other Tips
Be diligent in leak detection and arrest to ensure lubricants don’t attract dirt. Keeping equipment clean will spot leaks as soon as they start. Change filters every oil change to ensure no contaminants bypass a clogged filter into the lube system and into the bearings.

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Contact Ken Bannister at (519) 469-9173 or by email at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Work output in a potash mine is dependent on machines with high mobility and production efficiency. As the world’s demand increases for potash that is used primarily as an agriculture fertilizer, Saskatchewan’s PotashCorp has stepped up production at the company’s Rocanville, Sask., mining facility with a continuous bore mining machine that extracts some 1,200 tons of potash ore per hour.

Propelling the massive four-rotor mining machine, weighing in at 250 tons, are two Eaton Hydrokraft 250-cc motors that are the heart of the hydraulic system on the X CEL 44 Series miner built by Prairie Machine & Parts Manufacturing Ltd. in Saskatoon.

PotashCorp has relied on Regina’s HyPOWER Systems Inc., an Eaton distributor, to provide hydraulics muscle and hydraulics commonality for its mining machinery. When the need for an additional miner became evident, PotashCorp asked HyPOWER to redesign hydraulic circuitry for the machine and to work with Prairie Machine on fit, functionality and integration requirements.

Delving into the project, HyPOWER technical sales representative Ken Pagan and mechanical engineering technologist Cal Ganshorn called on Eaton’s Lyle Meyer, Hydrokraft product manager, for a two-speed hydraulic motor recommendation.

“We explained to Lyle that the motors would need to increase tram speed over PotashCorp’s current miners that move at a snail’s pace through the mine,” Ganshorn says, “plus fit into a tight envelope on the miner.

“In addition, the motors would need to default to maximum displacement, in the event that hydraulic system pilot pressure was lost.”

Meyer proposed Eaton’s compact Hydrokraft two-speed motor for the application, after confirming with Eaton’s Wehrheim, Germany, manufacturing facility that a customized version would default to maximum displacement, not minimum displacement, as does the standard version, when pilot pressure is lost. Ganshorn specified the custom Hydrokraft motors into his hydraulic system design proposal that also included Eaton DG4S4 valves, V Series vane pumps and a Series 2 piston pump that would operate auxiliary functions.

PotashCorp liked the design proposal and gave HyPOWER its endorsement to design the miner’s hydraulic system around the custom Hydrokraft motor.

Following assembly and testing, the miner was completely disassembled in order to be transported down the mine shaft. Simultaneous with these projects was the task of carving out rock 3,200 feet below the Saskatchewan prairie in order to build a shop in which to reassemble the 38-foot-long by 22-foot-wide miner piece by piece. Overall, the multimillion-dollar investment is already paying off for PotashCorp. The machine has been up and running since November 2009 and is significantly faster than the elder PotashCorp miners.

“Our hydraulic system design with the Eaton Hydrokraft motors has enabled the new X CEL miner to increase tram speed by 40 percent,” Ganshorn notes.

The increased tram speed saves two hours of tram time and more, says PotashCorp’s Cecil Huber, general maintenance foreman underground. “The time savings frees up the operator to help with setup sooner and allows us to move the electrical set that much sooner as well,” he says.

“Eaton’s Hydrokraft motors give us twice the drive torque to the tracks, which results in better control. Tram pressures are lower, resulting in lower operating temperatures in the hydraulic system.”

PotashCorp plans to add five more X CEL miners equipped with Eaton products to its Rocanville machinery lineup.

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This is an edited article provided by Eaton’s Hydraulic Group. For more information, visit www.eaton.com.

The high cost of energy has placed a premium on finding ways to reduce energy consumption in the food production process. Fortunately, there are steps maintenance and plant managers can take to improve operating efficiencies and positively impact the bottom line.

1. Electric Motors
AC motors are the most commonly used motor in Canadian industry, accounting for 80 percent of integral horsepower used in industrial and commercial sectors. These motors account for 10 to 20 percent of the total electricity consumed in Canada. The initial purchase price of a motor represents only two percent of its total lifetime cost while power usage represents almost all of the rest.

Motors that meet specifications established by the NEMA Premium program are available from most manufacturers and will optimize efficiency, reduce power consumption, and improve system reliability. A relatively small upfront investment will pay back quickly and also pay dividends in energy savings for years to come. The savings are so significant, that it can be worthwhile to replace fully serviceable standard efficiency motors.

Additionally, NEMA Premium motors are made to higher manufacturing standards, which typically results in longer life, less maintenance and reduced downtime.

It's important to know if a particular motor is the proper size for its application. A motor that is too large for the job wastes energy and costs extra money to operate. To help in this analysis, suppliers of AC and DC motors publish straightforward sizing procedures.

A well-planned energy management program, coupled with proper motor maintenance, can reduce operating expenses and increase profits. Proper motor maintenance will enhance efficiencies and prolong a motor's life. Items to check during inspection are old or inadequate lubrication; vibration; improper ventilation; dirt or other contaminants; misalignment; variation in load conditions; worn belts, sheaves and couplings; and loose hold-down bolts.

2. Gear Reducer Options
Substantial energy and operating cost savings are gained by combining premium efficient motors with highly efficient gearing. Your choice of gearing can have a significant impact on energy usage. Gearing is a common method of speed reduction and torque multiplication; however, during this process, the gearing consumes a certain percentage of power. Obviously, as power losses are reduced or minimized, efficiency improves.

Worm gearing, for example, is widely used in packaging machinery, material handling, and food processing industries. Worm gears are generally compact and economical, but not your best choice for energy efficiency. There is a lot of friction caused by the worm gear design and at high ratios this can cause the reducer to be only (approximately) 50 percent energy efficient.

Helical gear reducers are commonly found on conveyor lines, in packaging applications, and in a range of food manufacturing operations. When concerned with optimizing efficiencies, helical gearing is a better choice than worm gearing, offering a significantly higher efficiency at 98 percent per reduction.

Hypoid gear technology is another option, delivering efficiencies up to 85 percent across all ratios. Food-grade hypoid gear drives are designed for harsh environments, and they are generally maintenance-free, compact and quiet. These reducers are commonly used on batching equipment, conveyors, feeders, loaders, packaging equipment, pumps and more.

3. Belt Selection
Properly designed belt transmission systems are highly efficient. However, they require periodic maintenance to ensure efficient operation. In addition, certain types of belts are more efficient than others.

V-belts are used in the majority of belt drives. These belts have a trapezoidal cross section that wedges into pulleys to increase friction and power transfer capability. In operation, V-belt efficiency can deteriorate by as much as five percent over time if the belt is not periodically re-tensioned, as under-tensioned belts lead to slippage and reduced power transfer efficiency.

Cogged belts have slots that run perpendicular to the belt length. These slots reduce belt bending resistance and allow the belts to be used with V-belt pulleys. Cogged belts run cooler, last longer and are about two percent more efficient than standard V-belts. Therefore, cogged belts should be considered as replacements for V-belts wherever possible.

Synchronous belts have teeth and require the installation of mating toothed drive sprockets. These belts are about 98 percent efficient and maintain that efficiency over a wide load range. Synchronous belts require less maintenance and retensioning, operate in wet and oily environments, and run slip-free.

However, while synchronous belts are extremely efficient, cogged belts may be a better choice when vibration damping is needed or shock loads cause abrupt torque changes that could shear a synchronous belt's teeth. Synchronous belts also make a whirring noise that might be objectionable in some applications.

Additionally, proper belt alignment and tensioning are critical to ensure efficient operation. Improper tensioning leads to inefficient power transmission, belt failure and associated costs. If a belt is not running at optimum tension, it is wasting energy and money. Manufacturers offer a variety of tools that help ensure the proper installation of belt drives, including alignment tools and tension guides.

Another maintenance concern and efficiency loss is sheave wear. Misalignment and improper belt tensioning can cause excessive wear on sheaves. When sheaves wear, a formerly flat groove sidewall takes on a concave shape and the surface that interacts with the belt is compromised. Eroded sheave sidewalls can cause up to 12 percent loss in V-belt drive efficiency; and rough, worn sidewalls can reduce belt life by up to 50 percent. Belt manufacturers offer sheave gauges to help assess the condition of the sheave wall and make good decisions regarding replacement.

4. Variable-Frequency Drives
Variable-frequency drives (VFDs) have long been known to save energy, specifically in pump and fan applications. In fact, studies have shown the payback period is often less than one year. In most food processing facilities, pumps and fans run at constant speeds, and automatic valves or other mechanical means adjust flow rates. This can be highly inefficient because motors running at constant speed always consume the maximum amount of energy, even during periods when lower speed operation would suffice.

VFDs provide more efficient operation by regulating motor speed — and therefore flow rate — electronically in response to changing operating conditions.

In addition, VFDs can be used to improve process control. If a plant uses constant-speed motors to run conveyors on the line, it either must run without material during the time required to change temperature in a heat zone or produce scrap during this period.

When using a VFD, the time needed to change speed is significantly less than the time it takes to change heat-zone temperature. By adjusting the material flow continuously to match heat zone conditions, a plant can operate continuously. The results are decreased energy usage and less scrap.

5. Sealants
Most food manufacturing and processing operations utilize pneumatic controls and systems. Leakage is the major cause of inefficiency in compressed air systems. Thread sealants seal air lines while allowing for post-assembly adjustments. A quality sealant can withstand temperatures to 400°F and seal at operating pressures up to 10,000 PSI without cracking or shrinking. This is a simple, inexpensive way to save thousands of dollars in energy costs each year.

While food processors can't control rising global energy costs, they can take control over their in-plant operating efficiencies and, consequently, reduce energy consumption by equipment and systems.

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Jennifer Werger is with Applied Industrial Technologies. For more information about energy maintenance programs, visit www.applied.com/motormanagement.