Can you imagine driving a car without an engine, or any machine without electricity? Of course, your answer would be a big NO, and the same thing happens with machines. Every machine needs efficiency, and efficiency requires solid lubrication for excellent performance. Lubrication plays a major role in machines, with its main function being to reduce friction and lubricate each part of the bearing. There are two types of lubrication for bearings: oil versus grease. Both lubricants are important for lubricating rotating bearings to avoid damage.

What is the purpose of lubrication?

Lubrication is the process of controlling friction and wear by introducing a friction-reducing layer between moving surfaces in contact. The lubricant used may be fluid, solid, or plastic. Surfaces can be lubricated with a variety of materials, the most common being oils and greases. Lubricant is made with oil and a thickening agent, to keep it consistent, while oil activates lube. Oils can be synthetic, vegetable, mineral, or a combination of these.

Bearing lubricants containing oil include additives that improve, enhance, or modify the qualities of the base oil. The amount of additives used is determined by the type of oil and its intended purpose. For example, a dispersant may be added to engine oil.

The functions of a lubricant include:

• Reducing friction
• Preventing wear
• Protecting equipment against corrosion
• Controlling temperature (heat dissipation)
• Controlling pollution (transporting impurities to a filter or sump)
• Transmitting power (hydraulic)
• Establishing a fluid seal

A good lubricant should have:

• High viscosity so that machine bearing lubricant, bearing parts can perform better. The higher the viscosity of the lubricant, the better its ability to offer boundary lubrication, which refers to a boundary between moving parts.

Types of Lubrication:

Bearing lubricant, Lubrication is classified into three types: boundary, mixed, and full-film. Each type is unique, but they all rely on lubricants and additives in the oils to safeguard against wear.

Full-film lubrication can be divided into two types: hydrodynamic and elastohydrodynamic. Hydrodynamic lubrication occurs when two sliding surfaces are completely separated by a film of fluid.

Elastohydrodynamic lubrication is similar but occurs when the surfaces roll relative to one another. In elastohydrodynamic conditions, the film layer is significantly thinner than in hydrodynamic lubrication, and the pressure on the film is higher. The film is called elastohydrodynamic because it deforms to lubricate the rolling surface.

As we already understand what lubrication is and its function, do you know the mistakes that you should avoid? Let’s understand:

Mistake 1: Over- and under-lubrication-

Adding too much or too little grease is one of the most prevalent errors in our industry. As previously discussed, too much oil accumulates, causing higher friction and pressure, which generates excess heat. Too little grease reduces the life of bearings in the same way.

Mistake 2: Lubricating on a schedule rather than based on condition-

While lubricating a bearing once a week or once a month may seem like a sensible task, it actually harms your bearings more than it helps them. Grease is used in bearings for one reason: to prevent and reduce friction. If the lubricant is working properly, there is no need to change it or add more. According to Maint World, you can use ultrasound to monitor, measure, and trend friction levels rather than re-lubricating a bearing on a schedule, allowing you to know exactly when it's time to grease.

Mistake 3: Using a Listen-Only" Ultrasound Instrument

Simply put, using an ultrasonic device that only provides audible feedback to listen to a bearing may seem like a good idea in theory, but it will only hurt you in the end. Audible feedback alone is ineffective since no two people hear the same thing, making it impossible to draw any meaningful conclusions. It's also difficult to recall what a bearing sounded like months ago based solely on memory. An easy solution is to use an ultrasound with digital decibel measuring. If you have access to a device with various condition indicators, you can use it.

There are clear benefits to improving your bearing lubrication and avoiding these three mistakes.

Best grease for bearings

SKF lubricants are engineered to meet your specifications and have been tested in real-world situations. Our knowledge of bearings, lubricants, and applications enables us to recommend the best lubricants for your needs while also improving your entire lubrication strategy.