One of the most imperative things an operator can do for his/her machinery is to make sure it is properly lubricated.
So, what a lubricant is and how does it affect operations when used correctly? This article will answer all the questions and more by covering the fundamentals of lubrication. It will be discussed how a lubricant works to remove friction, the physical and chemical attributes of the lubricant, and the many other characters of a lubricant.
Many people and lubricant companies in India strongly believe that a lubricant is basically used to make things “slippery” and “smooth”. While it is the primary function, there are more advantages to using the right lubricant.
In addition to friction reduction, it also lessens the amount of wear that occurs during operation, lessens operating temperatures, reduces corrosion of metal surfaces, and assists in keeping contaminants out of the system.
Lubricants have a lot of characteristics that can be mixed and suit to meet your operating needs. For example, there are different chemicals that can be attached to permit a machine to run efficiently at extreme temperatures. We can also make a lubricant even more effective in protecting machine surfaces under extreme pressures.
By looking at the demands of the given machine, you can correctly identify the type of lubricant best suited for its proper function.
What Is Lubrication?
To properly understand what lubrication is, you first need to know why we actually use it. Friction is that force that resists relative motion between two bodies in contact. If friction does not exist, nothing would ever stop moving. We need friction to function, but there are times where you want to be able to minimise the amount of friction present there.
When you rub your hands together, you create some sort of heat because of the friction between the sliding surfaces of your hands. Now you imagine, rubbing your hands together 3600 times a minute – your hands would be on fire!
The same exact heat is produced by friction in your machinery. If in your equipment, the lubricant has not been selected appropriately with standard operating temperatures, load, speed, etc., in mind, catastrophic failure might result.
You could clean your bearings or if you refrain your motor, for example, and the machine is way too hot, you could seize the bearings. Either way, both are expensive when you consider time lost, manpower used and purchasing new equipment from the oil lubricants manufacturers.
In order to ignore failures of this nature, we lubricate our machinery to reduce the resistance to movement, and as a result, reduce the amount of heat produced. The heat that is produced by the gadget is transferred to the oil so that it may be removed by a lube oil cooler.
There are a lot of considerations that must be appealed when choosing the type of lubricant, we need to use: viscosity, additives needed, properties, etc.
Minimizing friction and reducing heat are only a couple of the reasons why we use lubricants. If you look under a microscope at two surfaces moving across each other, you would see something that resembles, two mountain ranges rubbing against one another. As this happens, pieces of the weaker material break off and create smaller abrasive particles, which results in more broken off pieces, which go on to create more abrasion.
It’s a brutal cycle, and the way we save this from occurring is by creating a lubrication film. Two of the preferred and most common types of fluid related lubricant films are hydrodynamic and electrohydrodynamics. Hydrodynamic films are available between sliding contacts. The most common example of this is a journal bearing.
What Makes Up the Lubricants We Use?
All lubricants initiate with a base oil. There are three types: mineral, synthetic, and vegetable. In industrial use, we usually deal with mineral and synthetic, so I would like to focus on these. Mineral oil comes from crude oil and the quality depends on their refining process.
There is a grading scale for oil and different approaches which requires different oil quality. Mineral oil is basically made up of four different types of molecules – paraffin, branched paraffin, naphthene, and aromatic. Paraffinic oil consists of a long, straight chained type of structure, while branched paraffinic oils are the same with a branch off the side.
Synthetic oils are man-made fluids that have similar straight chained structures, much like the branched paraffinic oils. One of the advantages of a synthetic is that the molecular size and weight remain constant while mineral oils vary greatly; therefore, the characteristics are very predictable.
The higher the oil’s density, the slower it flows. Molasses, for example, has a very high density while baby oil has a very low viscosity. The viscosity required for an application totally depends on its speed, operating temperature, and type of bearing as well as the type of component, like a gearbox versus a motor.
Dispersants assists in saving components against abrasion from the wear products by enveloping particles and suspending them in the oil so that they may be easily flushed and removed from the system. Extreme pressure (EP) additives react with a component’s surfaces to form a thin protective layer to stop metal-to-metal contact.
There are advantages of using grease as opposed to oil in certain applications. Grease seals out adulterants is greater suited for insoluble solid additives like molybdenum disulphide and graphite and has better stop-start performance because it doesn’t even void away like oil, for a lower chance of a dry start.
However, the broadness of grease limits bearing speed reduces cooling of components, makes for difficult sampling and analysis, and makes it difficult to determine the proper amount of grease that needs adding. This is something which is imperative and must be taken into consideration when deciding if oil or grease would be better suited for the application.
With a basic understanding or knowledge of lubrication, you can see there are quite a few advantages of using the proper lubrication in your machines. Higher efficiency, longer life, better reliability, and only less money spent on maintenance are goals that every company strives to have.