Lubrication

Lubrication is an important and experienced part of this group.Yekta Group supported and implemented the lubrication programs of Iran's refining and pipeline industries for twenty years, citing the recommendations of NORIA and ICML and their training cases.

As one of its permanent affairs is the regular conditioning program of turbine and hydraulic oil of Iran Oil Pipelines and Telecommunications Company.

Lubrication Meaning

Lubrication is the control of friction and wear by the introduction of a friction-reducing film between moving surfaces in contact. The lubricant used can be a fluid, solid, or plastic substance.

Although this is a valid definition, it fails to realize all that lubrication actually achieves.

Many different substances can be used to lubricate a surface. Oil and grease are the most common. Grease is composed of oil and a thickening agent to obtain its consistency, while the oil is what actually lubricates. Oils can be synthetic, vegetable or mineral-based as well as a combination of these.

The application determines which oil, commonly referred to as the base oil, should be used. In extreme conditions, synthetic oils can be beneficial. Where the environment is of concern, vegetable base oils may be utilized.

Lubricants containing oil have additives that enhance, add or suppress properties within the base oil. The amount of additives depends on the type of oil and the application for which it will be used. For instance, engine oil might have a dispersant added.

A dispersant keeps insoluble matter conglomerated together to be removed by the filter upon circulation. In environments that undergo extremes in temperature, from cold to hot, a viscosity index (VI) improver may be added. These additives are long organic molecules that stay bunched together in cold conditions and unravel in hotter environments.

 

This process changes the oil’s viscosity and allows it to flow better in cold conditions while still maintaining its high-temperature properties. The only problem with additives is that they can be depleted, and in order to restore them back to sufficient levels, generally the oil volume must be replaced.

 

 

Machine lubrication should play a role in any maintenance strategy, with the potential to yield a significant return on investment in materials and resources. What is equipment lubrication? It is the practice of introducing a lubricating agent — almost always an oil — into machine components to achieve several goals:

 

• Reduce friction : Improve overall lubrication either by changing viscosity, using differing or improved additives or through the use of different lubricants
• Lower component and operating temperatures: operating temperature is the allowable temperature range of the local ambient environment at  mechanical device operates
• Wick away debris and contaminants:It also wicks and captures moisture from inside the reservoir, ... and channel contaminants away from bearing and lubricant-reservoir areas.

 

Lubrication is critical for, essentially, any moving parts that encounter one another in a machine. Most frequently, these are rotating parts and components such as gears. Machine lubricant is designed to prevent:

 

• Undue wear and tear on components:Wear and tear is a form of depreciation which is assumed to occur even when an item is  and with care and proper maintenance.
• Premature failure of components:Vibration and premature failure of machine components usually stem from a poor installation, system design, foundation design.
• Excessive unplanned maintenance: Preventive maintenance table for equipment & facilities is  important part of maintenance .Some signs when you are doing too much.
• Equipment overheating:Overheating causes damage to the circuit components and can cause fire, explosion, and injury. Damage caused by overheating is usually irreversible.
• Part seizure: seizures are also called partial seizures since they begin in one area of machine. They can be caused by any type of focal injury that leaves scar tangles.
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There are generally two major fallacies about lubricating machinery: 1) that it is a simple process, and 2) that it is optional or “as-needed.” Both are false. While the concept of lubrication is relatively simple, it is a technical process that must be considered and treated as such to yield the greatest benefits. Lubrication should also be considered a mandatory part of a comprehensive maintenance program.

 

When both points of view are accepted, a lubrication strategy may provide you with major ROI in uptime, equipment service life, part quality and more.

The concept of lubrication is related to that of friction. Friction is a force generated when two objects move against one another — think of one gear interacting with another. This force converts kinetic energy (movement) into thermal energy (heat), which can quickly become a significant level of heat at high speed and frequency. Lubrication introduces another element or medium into the friction equation to transfer heat away from the point of friction. It plays several other roles, as well.

Lubrication Regimes

The thickness of a fluid film is dependent on a fluid’s viscosity, the load between the mating surfaces, and the speed at which those surfaces move with respect to each other. There are four lubrication regimes, also referred to as modes of lubrications, defined by the thickness of the fluid film as follows:

 Hydrodynamic lubrication regimes exist when the fluid film supports the load eliminating all solid surface interactions. This lubrication regime exists when the geometry, surface motion, and fluid viscosity create enough fluid pressure to cause hydrodynamic lift.

 Elastohydrodynamic  lubrication regimes are formed when higher loads exist or when there is nonconformal contact between the lubricated surfaces. This causes a localized load-bearing area that imposes some amount of elastic strain across the solid surfaces.

The extreme pressures experienced affect the viscosity of the lubricant. This change in viscosity allows the fluid to support the load, effectively lubricating point contacts in applications such as ball and roller bearings.

Mixed lubrication regimes insufficiently separate solid surfaces allowing some amount of solid surface interaction. As the name suggests there is an active fluid film that lubricates the surface while asperities, which are surface irregularities, cause what can be referred to as micro-elastohydrodynamic lubrication.

Boundary lubrication regimes allow the asperities to support the load, as the surface roughness exceeds the thickness of the fluid film. In these circumstances the lubricant no longer acts directly to limit friction. To effectively lubricate surfaces experiencing a boundary lubrication regime, extreme-pressure (EP) additives, boundary additives, or solid lubricants can be used to decrease the negative effects of the solid surface contact.

Applications

Lubricants are designed to produce a desired effect in known operating conditions. They are often application specific as each application requires unique properties under diverse environmental conditions.

 

    These roles include:

Part wear reduction: As parts move against each other, contact points begin to erode. Lubrication provides a buffer against this raw wear.
    Shock absorption: Lubricant can dilute the impact and effect of shock and vibration on parts, further reducing wear while maintaining proper, consistent operation.
    Corrosion reduction: Lubricant protects metal surfaces from environmental elements that can lead to corrosion.
    Drawing debris and contaminants away from moving parts: As moving parts come into contact with each other, they begin to erode. The pieces of debris that form because of this can then lead to further friction and erosion. Lubrication serves to move these tiny (and large) contaminants away from moving parts to reduce further damage.
    Friction and heat reduction : Already mentioned above, these functions are the primary role of lubrication, and should be reiterated. By reducing friction forces and the heat that they generate, machinery lubrication can reduce wear and tear, lower the chances of significant component or equipment damage, and yield equipment performance improvements such as increased uptime and less maintenance.

 

 

lubrication of machinery provides numerous benefits, including:

 

• Longer component and equipment service life : By reducing friction and heat  and thus wear and tear  lubrication allows equipment and components to remain in an optimal operational state for a longer period of time.
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• By helping components to remain intact and closer to their “out of the box” form, the time between breakdown and replacement requirements will be extended, improving OEE and reducing overall costs.
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• Reduced maintenance needs: With less wear and tear comes less potential for breakdown. Parts that are operating with high friction and high heat are susceptible to unexpected failure and breakdown at just about any time, regardless of the age of the component.
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• Proper lubrication keeps equipment operating at an acceptable temperature and friction level, vastly reducing the potential for unexpected maintenance requirements.
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• Higher part quality: Lubrication allows for more consistent operation by helping to absorb shock and vibration and keep equipment running as expected. This translates to increased repeatability and quality in part production, creating fewer rejects and a higher productivity yield.
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• Safer operations: Any time equipment is operating at a high level of heat and with increased vibration — as would be the case in unlubricated or insufficiently lubricated equipment — there is a potential for catastrophic failure, which can create a danger to equipment operators and other employees. Proper lubrication is critical to a safe working environment.
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• Lubricant specifications are internal documents that contain the technical standards, performance requirements and industry approvals for every lubricant used in the facility or fleet. They may include information on product safety, proper disposal or alternative products available on the market.

• Among the lubricants typically found in these specifications are gear oils, turbine oils, hydraulic fluids, compressor oils, greases, solid lubricants, multi-purpose bearing oils, engine oils, cutting fluids, total-loss lubricants and others.

• For small facilities or fleets, creating lubricant specifications can be a relatively simple exercise. However, the complexity often increases according to the facility’s equipment diversity or the number of sites involved. The more complex the facilities or the higher the number of sites involved, the greater the value of creating specifications.

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• :Types of Lubrication

  There are three different types of lubrication: boundary, mixed and full film. Each type is different, but they all rely on a lubricant and the additives within the oils to protect against wear.
  
  Full-film lubrication can be broken down into two forms: hydrodynamic and elastohydrodynamic. Hydrodynamic lubrication occurs when two surfaces in sliding motion (relative to each other) are fully separated by a film of fluid.
  
  Elastohydrodynamic lubrication is similar but occurs when the surfaces are in a rolling motion (relative to each other). The film layer in elastohydrodynamic conditions is much thinner than that of hydrodynamic lubrication, and the pressure on the film is greater. It is called elastohydrodynamic because the film elastically deforms the rolling surface to lubricate it.
  
  Even on the most polished and smooth surfaces, irregularities are present. They stick out of the surface forming peaks and valleys at a microscopic level.
• These peaks are called asperities. In order for full-film conditions to be met, the lubricating film must be thicker than the length of the asperities. This type of lubrication protects surfaces the most effectively and is the most desired.
  
  Boundary lubrication is found where there are frequent starts and stops, and where shock-loading conditions are present. Some oils have extreme-pressure (EP) or anti-wear (AW) additives to help protect surfaces in the event that full films cannot be achieved due to speed, load or other factors.
  
  These additives cling to metal surfaces and form a sacrificial layer that protects the metal from wear. Boundary lubrication occurs when the two surfaces are contacting in such a way that only the EP or AW layer is all that is protecting them. This is not ideal, as it causes high friction, heat and other undesirable effects.
  
  Mixed lubrication is a cross between boundary and hydrodynamic lubrication. While the bulk of the surfaces are separated by a lubricating layer, the asperities still make contact with each other. This is where the additives again come into play.
  
  With a better understanding of this process, it should be easier to define what lubrication actually is. It is a process of either separating surfaces or protecting them in a manner to reduce friction, heat, wear and energy consumption. This can be accomplished by using oils, greases, gases or other fluids. So the next time you change the oil in your car or grease a bearing, realize there is more going on than meets the eye.
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 The main purpose of industrial lubricants is to reduce the friction between two machine parts. Lubricating oils absorb heat, so if used, they can help balance the temperature and prevent heat damage. Because lubricating oils protect machinery, it means less maintenance and repairs, saving your business time and money. If your machinery can malfunction Less work equals more work and less chance of failure.

 Equipment maintenance is necessary to ensure that the equipment continues to be a useful tool for manufacturers. All machines contain parts that rub against each other during operation. In order to reduce this friction and thus increase the life.

For the operation of machine parts, their regular lubrication is vital. In rotating machinery, lubricants reduce friction and wear, dissipate heat, protect surfaces, keep foreign contaminants out, and remove wear particles. It's important to do an inspection every morning before you start your machinery.

It doesn't have to take a long time, but you should get into the habit of inspecting your machinery to make sure nothing is broken or showing signs of wear and tear. There is no abnormal wear and tear. One thing that is often overlooked is lubrication. Make sure your equipment is properly lubricated.

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Yekta Group, 2 important parts : WORLD-CLASS OIL ANALYSES PROGRAM  & OIL CONDITION MONITORING recommends and proposes to make your machines work better , also reduce the current & operating costs of your organization or company.

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