In this deep dive webinar on enterprise analytics, titled, “Operationalizing Analytics and IT,” Gahl Berkooz, chief analytics for General Motors Connected Customer Experience Division, locks into a discussion on the different approaches for managing analytical functions. Crucial foundations are being set as more than “half of manufacturers are using IIoT sensors and related technology for at least a year now,” according to a 2016 Genpact Study.
In this webinar, Berkhooz discusses centralized and decentralized data analytics, how data obliterates business silos and what approach works best. Berkhooz also identified four organizational structures that different companies are using in a HBR recent article.
Four Organizational Data Approaches:
- A stand-alone data and analytics service function
- An integrated operational data and analytics function
- Data and analytics integrated as part of IT
- Data and analytics embedded in operating divisions
Among other factors, motor and gearbox lubrication programs require understanding and a controlled lubrication approach.
By Ken Bannister, MEch Eng (UK)CMRP, MLE, Contributing Editor
When a driven component is required to operate at a speed different than that of the attached motor (driver), a designer can choose from two basic power-takeoff speed-reduction/increaser methods. The first uses pulleys or sprockets of different diameters mounted to the motor and driven shaft, with power transmitted by a connective belt or chain. The second design connects the motor to the driven component through a gearbox, with the motor connected to the gearbox input shaft and the driven device connected to its output shaft.
When viewed in a maintenance-management-system database for lubrication purposes, belt/chain-drive motors and motor/gearbox units are rarely handled with separate PM work orders. Rather, the lubrication requirements are integrated as line items on a much broader machine PM work order. This is fine for sub-fractional and smaller horsepower motors. Larger, more expensive (and re-buildable), motors—usually 20 hp and more (there is no set rule to this)—require treatment as a separate entity from the parent machine, with their own asset numbers and PM/lubrication regimes, so as to compile work-history files. Furthermore, in the case of motor/gearbox combinations there are two specific entities, one electro-mechanical (motor), the other purely mechanical (gearbox), that are best treated individually when assessing and managing lubrication needs.
Assuring motor and gearbox reliability is the result of good alignment practices and, more importantly, effective lubrication practices.
Bannister on Lubrication
Accompanying this article is the first of a new series of monthly lubrication podcasts with Ken Bannister. This month, he provides additional information about factors involved in lubricating motors and gearboxes.
Motors are electro-mechanical devices that turn electrical energy into mechanical energy. Motor magnets and windings are wound on and around a central shaft. This shaft is simply supported by two or more rolling-element bearings at each end of the motor frame and housing. These bearings are the only lubrication points on a motor, and are virtually always grease lubricated. With rare exception, fractional- and small-horsepower motors use sealed bearings and make no provision for external bearing lubrication. If the motor is balanced, aligned, and not overloaded, it should deliver a long life with no additional lubrication. This is not usually the case with larger motors, which are often subjected to heavier and often more variable loads, requiring larger bearings.
Depending on the motor design and manufacturer, external grease fittings usually are installed on motors rated at 5 hp and become much more prevalent on 20-hp units. When motors become more powerful and heavier, they place more load on the bearing points, therefore requiring grease replenishment on a more-frequent basis.
If a motor is to operate at peak efficiency, its bearing cavities (the available space between the balls, raceways, cage, and seals) need only be filled to 30% to 50% capacity, at any time. Because the bearings are hidden behind end plates, they are lubricated “blind” and are often subject to overfilling—especially with manual greasing. When this happens, the grease has nowhere to go except through the bearing cavity into the winding! Grease-filled windings lead to premature failure and a rapid decrease in motor energy efficiency, evident by the rise in motor’s amperage draw.
To alleviate this condition, larger motors are designed with a drain-plug or screw in the end cases that, once opened, will allow excess grease to flow through the bearing and out of the motor end case. If this is kept closed during the greasing process, excess grease will channel directly into the motor windings. If your motor has a grease fitting but no drain plug, use extreme caution not to over-lubricate, as the excess will make its way into the winding.
Over-lubricated bearings will produce excess heat through internal fluid friction that can easily be detected with an infrared camera. This can also be achieved by adding contaminated grease with a dirty grease nozzle or through cross contamination with a non-compatible grease.
Grease-gun inconsistency can be ironed out through use of a single-point auto lube (SPL) setup to deliver a small amount of lube on a continuous basis for as long as a year, depending on the size of bearing and lube reservoir.
SPL manufacturers have setup guidelines based on bearing size and altitude (atmospheric pressure is relational to constant-pressure grease flow) for initial setup, which can then be fine-tuned by monitoring amperage draw and/or bearing temperature. These signatures will be unique to each motor and will differ based on size and load.
Gearboxes are self-contained mechanical devices that allow power to be transmitted from an input shaft to an output shaft at different speeds through the meshing of different-sized gear sets held on each shaft. The gears and shafts are supported on bearings contained within a sealed “box” that also serves as a reservoir for the lubricating oil. Gearbox dimensions can range from palm-sized to room-sized. With few exceptions, all are oil lubricated.
Depending on the style and size, gearboxes employ a number of methods to move the lubricant over the gears and bearings, the most popular being:
• Splash lubrication. This is a common gearbox-lubrication method in which the reservoir is filled part way with lubricating oil to ensure partial coverage of all the lower mating gears. At speed, these gears use surface tension on their teeth to “pick up” lubricant and transfer to other gears and bearings through meshing and by “flinging and splashing” the lubricant in all directions within the sealed reservoir.
• Pressure lubrication. This method is frequently found on mid- to large-sized gearbox assemblies that use a gear-driven pump, typically located inside the gearbox, to work in conjunction with the “splash” method. Pressure-lubrication systems draw lubricant from the reservoir through a pickup-filter screen and pump oil at pressure through an internal piping system to bearings and gears that would be difficult to service with splash lubrication.
• Mist, or atomized, lubrication. This approach, reserved for the largest of gearboxes, uses a vane-style pump that picks up lubricant from the reservoir and “slings” it at a plate, causing it to atomize into a micro-drop mist. The mist saturates all of the mechanical components within the sealed gearbox.
In all three lubrication methods, choosing the correct oil viscosity and additive package is most important. Typical to all gearboxes is the need to ensure:
• No cross-contamination of lubricants occurs during oil top-ups or change-outs. Label your gearbox with the correct oil specification.
• No dirt or water contamination is allowed into the gearbox.
• The drain, fill, and breather caps are always tightly in place.
• The gearbox is regularly wiped clean of dirt and debris that will act as a thermal blanket and unnecessarily heat up the oil.
• The gearbox is not over-filled creating churning (foaming) of the oil that can rapidly deplete the anti-foam additive, causing the oil to oxidize. This requires attaching low- and high-level markers to the gearbox sight gage.
If you have all of the above practices in check, make enquiries regarding the use of synthetic gear oils. These not only last longer but can cut your energy consumption as much as 4%. MT
Ken Bannister is co-author, with Heinz Bloch, of the recently released book Practical Lubrication for Industrial Facilities, 3rd Edition (The Fairmont Press, Lilburn, GA). As managing partner and principal consultant for EngTech Industries Inc. (Innerkip, Ontario), he specializes in the implementation of lubrication-effectiveness reviews to ISO 55001 standards, asset-management systems, and training. Contact him directly at firstname.lastname@example.org, or telephone 519-469-9173.
Optimizing a lubricant-delivery system is not difficult and the benefits are significant.
By Ken Bannister, MEch Eng (UK), CMRP, MLE, Contributing Editor
When a piece of rotating machinery is purchased, it almost always is delivered with a designed lubrication system or approach in place. The type of equipment can be as complex as a high-end, integrated, computer-controlled, automatic lubricant-delivery system that supplies each bearing point with a measured amount of lubricant based on time, cycle, or condition.
Or, if a site’s budget was tight during the initial specification and procurement process, its new machinery could arrive with a more modest form of lubrication technology involving inexpensive grease nipples and/or oiling points at each bearing point and the simplest of instructions in the operations and maintenance manual to “lubricate as necessary with a specified lubricant.”
Those examples represent the extremes in lubrication design and approach. Fortunately, from one extreme to the other and in between, maintenance-department personnel have the ability to tune lubrication-system setups to improve/optimize their particular lube-program deliverables. It’s not as daunting a task as it might seem.
Lubricant-delivery systems are typically designed with one or more areas of adjustability to allow tuning. Take advantage of this capability. Depending on the design mechanics of the system, tuning adjustability can be found in three major places: the metering devices, the pump, and the pump-control system.
Adjustable metering devices, such as those found in single-line, positive-displacement, injector (PDI) systems (oil or grease); dual-line injector systems (oil or grease); or pump-to-point box-cam systems (oil only) allow plant personnel to change the amount of lubricant charge that’s delivered to specified lubrication points. These types of systems are less expensive to design, as they require little or no initial design engineering and put the injector-calibration setup responsibility squarely on the user. The downside to this scenario is that it can easily lead to over- or under-lubrication if the user isn’t familiar with the equipment or doesn’t understand how to calculate a bearing’s lubricant requirements. Maintainers and machine operators can also tinker with settings at will if they feel a bearing requires more or less lubricant—a situation that doesn’t merely change the dynamic from adjustability to “tamperability.” It, too, can lead to over- or under-lubrication and, ultimately, premature bearing failure.
Tuning such systems necessitates calculating the hourly bearing requirement and determining the minimum-to-maximum lubricant output shot per cycle for each injector size/type. The accumulated total amount of lubricant is what must be pumped through the delivery system every hour, and the system must be set up accordingly. From this point on, with all injectors calibrated, any further adjustment is to be carried out at the pump.
Protecting these systems from tampering calls for controlled access. This can be accomplished in numerous ways, the simplest of which is “ganging” multiple injectors together, building a key-access lock-box around them, and allowing access only to designated lubrication or reliability personnel.
NOTE: Popular single-line-resistance and progressive-divider metering devices are non-adjustable. They depend on upfront engineering by the system supplier (incorporated in the cost of the system), before delivery to the machine builder or end user. Their setup adjustability is through pump-output calibration.
Lubrication pumps, controllers
Lubrication pumps, which come in many configurations and sizes, can be powered manually, electrically, or pneumatically. The delivery rate for all of these can be adjusted on the pump itself or through a pump controller.
Manual pumps are mechanically actuated with a lever arm connected to a positive-displacement piston. The output delivery can be adjusted by restricting the length of the piston stroke with an adjustment at the lever cam. Lubricant is manually drawn into a single-acting piston chamber by moving the lever arm in a back-and-forth arc motion. The lubricant is then moved out of the pump through an internal check valve to the distribution lines and on to the metering devices. The pump is returned through opposite action on the lever or by a return spring.
If reciprocating or rotary machine motion is available, the lever arm of the manual pump can be replaced with a power-takeoff pitman-arm linkage attached to the motion device. The photo on the previous page shows a series-progressive distribution system with a mechanical pump attached to a pitman arm that’s connected to a large-diameter rotating-machine shaft. The shaft attachment point is offset from the center to produce a reciprocating (up and down) arm motion that produces a rocking motion at the pump shaft. This emulates the back-and-forth motion of the manual lever arm.
By changing the length relationship of the pitman-arm attachment point and arm, the degree of arc will change and speed up or slow down the number of pump strokes per hour. As evidenced by the surplus grease around the bearing in the photo, the pump setting is incorrect and needs to be recalibrated to reduce the amount of lubricant delivery.
Pneumatically or electrically powered lube pumps are sized according to the system output requirement per hour. For effective lubrication, smaller amounts of lubricant, delivered on a frequent basis, e.g., every 10, 15, or 20 min., are preferable to a large amount that’s delivered hourly. This approach allows the designer to use a smaller, less expensive output pump and control and provide the ability to adjust total delivery through the number of actuations or lubrication cycles per hour. Setup is accomplished through programming (adjusting) the on/off timer that controls power to the pump.
Pump-lubrication cycles can be controlled in other ways, including through counters that calculate the number of machine or production operations, or by a condition signal, such as an amperage-draw meter that indicates an increase in energy draw from the machine-system motor (due to a rise in mechanical friction that’s most often caused by lack of lubrication). This popular control mechanism is used in automotive-assembly plants to measure the amperage of conveyor-drive and take-up motors that activate and deactivate conveyor chain and pin lubricators.
In simple, modestly priced, manual-grease systems, a grease-gun acts as the pump and metering device, while control is regulated by the grease-gun user and the scheduled preventive-maintenance (PM) instruction. Optimization and setup involves a two-step process in which the grease-gun’s displacement must be determined to first ascertain the number of shots required to meet the bearings’ calculated needs and, second, the frequency of application that must be controlled by the PM schedule. The number of grease-gun shots or the PM schedule is used to fine tune any increase or decrease in the lubrication amount or frequency.
Keep in mind
Automated lubricant-delivery systems are much more accurate, consistent, and easier to set up and control than manual systems. As a result, bearings run cooler (due to less friction), require less energy, and have as much as three times the service life of their manually lubricated counterparts. In short, return on investment from the relatively small purchase and implementation cost of an automated system is quickly realized.
Regardless of its design, a lubrication-delivery system should be evaluated on a bi-annual basis to assess its effectiveness. Those evaluations should include reviews of bearing-failure incidents, grease usage, changes in bearing running temperatures and energy draw, as well as checks for physical signs of over-lubrication and system neglect. As with the initial setup of these systems, a little adjustment later on—make that a little fact-based, correct adjustment—can pay enormous dividends. MT
Ken Bannister is co-author, with Heinz Bloch, of “Practical Lubrication for Industrial Facilities, 3rd Edition” (The Fairmont Press, Lilburn, GA). As managing partner and principal consultant for EngTech Industries, Innerkip, Ontario, he specializes in the implementation of lubrication-effectiveness reviews to ISO 55001 standards, asset-management systems, and training. Contact him at email@example.com, or telephone 519-469-9173.
Clean lubricants increase the life and performance of bearings and ensure the success of your operations.
By Ken Bannister, MEch Eng (UK), CMRP, MLE, Contributing Editor
I am astounded by the number of companies that continue to believe bearing failure and its associated replacement and downtime costs are an acceptable part of doing business. In my experience, this point of view is most apparent at sites with severe and semi-severe operating conditions, wherein water, heat, and fine particulate matter (dust, dirt, and manufacturing debris) are present.
If a machine has any form of replaceable/washable filter, screen, or breather as part of its fluid-management systems—lubrication, hydraulic, and pneumatic-air systems—we can assume the OEM (original-equipment manufacturer) machine designer/engineer expected the equipment and its operators/maintainers to contend with and manage fluid- and air-borne contaminants. These built-in sacrificial filtration elements are specifically designed to provide an inexpensive method of managing and controlling potential contamination issues—externally and internally—to protect delicate, close-tolerance, machine-bearing surfaces at work under a range of operating conditions.
In the majority of operating conditions, effective levels of contamination control and avoidance are achievable with minimum effort when the requirements and basic relationships of and between a machine, its operator(s), and maintainer(s) are understood.
The fact that a piece of equipment begins to run a process or make a product indicates the OEM has done its part: supplied a machine that’s adaptable enough to work in an array of different operating environments or, if the end user is fortunate, one designed and built specifically for a unique operating environment. This means the machinery is fitted with a number of built-in contamination-control/filtration devices that are ultimately designed to fail in their own right. (They also require monitoring for condition and cleaning and/or replacement when their filter media is close to being exhausted.) These devices offer secondary protection through their ability to trap and control the ingress of contaminants into lubricating oil(s), grease(s), and air-flow systems.
When two precision-bearing surfaces interact, they rely implicitly on a lubrication film devoid of particle or water presence to separate—and protect—themselves from each other. The filter is designed to trap and extract any particles or moisture before these contaminants can enter the lubricated zone(s) and cause surface damage.
Almost exclusively in contamination control, filters incorporate a passive surface-attractant medium, designed to work in the direct-flow path of the lubricant and capture any dirt particles (contaminants) held in colloidal suspension as the lubricant, or lubricated air, flows through or across it. Depending on the working conditions, particle size, and fluid-flow rate, the porous filter media can be constructed of a variety of materials, including simple wire-mesh gauze, wire wool, pleated paper, cellulose, porous metal, fiberglass, diatomaceous earth, or felt. Due to higher fluid viscosity and line-delivery pressures, grease systems use heavy-gauge coiled wedge-wire or wire-mesh filters to attract large solid contaminants that may be introduced from a dirty grease-gun nozzle.
Enclosed, sealed gearboxes and reservoirs require breather devices to equalize pressure and control solid and moisture contamination. Old-style breathers constructed of wire wool can only prevent large solid contamination (40+ microns in size), and are now regularly replaced with newer-style breathers that employ desiccant-like silica gel hydrophilic media.
This media type allows the reservoir to breathe and prevent airborne particulates (3+ microns) from entering the reservoir. It also wicks and captures moisture from inside the reservoir, while preventing outside moisture from entering the reservoir or gearbox chamber.
Heavy water contamination usually enters a system as a result of maintenance or production personnel using oil that has been incorrectly stored in the outside elements, or through production-process-water spillage or high-pressure machine-cleaning (prevalent in food-manufacturing machinery).
Ironically, while contamination avoidance is the primary strategy for reducing and eliminating premature bearing failure, it is absent/avoided in many lubrication programs. A good contamination-avoidance program requires little-to-no capital outlay, fits perfectly into any preventive-/predictive-maintenance (PM/PdM) program, involves cooperation of operators and maintenance personnel, and will drastically reduce the reliance and maintenance requirement of what essentially become secondary contamination-control systems.
In simple terms, contamination-avoidance means taking actions to ensure that contaminants don’t come into contact with a machine and its bearing-protection systems. Success relies, largely, on a good relationship between operations and maintenance personnel and a healthy respect for the machine and components in question. The following points outline the foundational requirements of any contamination-avoidance program:
Good housekeeping. Ensuring that dirt does not accumulate on equipment surfaces is preventive maintenance 101 and the responsibility of operator and maintainer. Implementing a simple 5S program will facilitate this element. This applies to the machinery and the lubricant-storage area and transfer equipment.
Lubrication training. Understanding the effect and consequence of failing to arrest contamination is mandatory. Use processes and procedures that ensure consistent effort.
Lubricant storage and transfer engineering. Using dedicated, color-coded, and closeable storage and transfer equipment protects lubricants from the elements and cross-contamination exposure. Make sure all grease guns and nipples are cleaned with lint-free rags before and after use.
Condition-based oil changes. Performing oil/filter changes too frequently risks exposure to contaminants. Performing them too infrequently risks exhausting filtration media and, in turn, lubricating-fluids degradation. Condition-checking allows operators and maintainers to become more familiar (or in tune) with a machine.
Lubricant cleanliness. Testing new lubricants and bulk fluids to verify their cleanliness and additive-package formulations before they’re put into use is a must. This is the only way to ensure that they’ve been delivered in a clean state and meet referenced specifications. In addition to the above behavioral changes, the following equipment and workspace changes can be put in place if the production process and workplace environment warrants:
Room-ventilation system. Positive or negative room pressurization or exhaust-air ventilation can be used to reduce or eliminate airborne contaminants.
Machine design. If the production process involves water or sand, mechanical deflector shields can be used to protect, divert, and channel contaminants away from bearing and lubricant-reservoir areas. Fill-cap and drain-port plugs can be replaced with positive-lock fill/drain connections that hook to closed-system transfer carts. Conventional breathers can be replaced with a closed-loop expansion tank on larger reservoir systems.
Taking small contamination-avoidance steps will significantly reduce your site’s lubricant-contamination-control requirements. The savings from these efforts can then help fund your world-class lubrication-management program. MT
Ken Bannister is co-author, with Heinz Bloch, of the soon-to-be-released Practical Lubrication for Industrial Facilities, 3rd Edition (The Fairmont Press, Lilburn, GA). As managing partner and principal consultant for EngTech Industries (Innerkip, Ontario), he specializes in the implementation of lubrication-effectiveness reviews to ISO 55001 standards, asset-management systems, and training. Contact him directly at firstname.lastname@example.org, or telephone 519-469-9173.
Accessing the new knowledge center through the website’s Technical Resources section, users will find a wealth of best-practice maintenance tips and key insights on issues that are affecting a wide range of industrial sectors, i.e., general manufacturing, mining, oil and gas, power generation, food and beverage, and others. The content includes, among other things:
- Expert Answers: Taken from ExxonMobil’s Mobil SHC Club industrial-lubricants community, these short articles answer a variety of lubrication-specific questions sourced from real customers.
- Industrial Application Expertise and Tips: A mix of in-depth articles and quick tips authored by ExxonMobil field and technical experts provide best-practice guidance on critical lubrication topics like safety, used-oil analysis, and lubricant selection.
- Industry Insight: Also authored by ExxonMobil experts, these industry trend articles outline “big picture” considerations that can help industrial operators enhance productivity and profitability.
- Success Stories: These real-world case histories show how customers throughout industry captured substantial benefits with Mobil-branded lubricants and ExxonMobil’s field-engineering support.
According to the company, the expanded content is part of a wider range of enhancements to the Industrial Lubricants website. For example, the site offers improved search functionality where visitors can simply search for equipment builders, lubrication specifications, and topics, to find the product and service information they need. Its responsive design offers optimized the viewing experience on any device.
CLICK HERE or go to mobil.com/industrial to learn more.
Thomas Kurtz, director of workforce solutions at Noria Corporation, talks about the company’s training and consulting in machinery lubrication and oil analysis at SMRP 2016.