Introduction
Bearing grease is used to prevent the metal parts of the bearings from contacting each other. Bearing grease becomes an essential part for the bearings to make them more efficient and increase their life-span. Though, the old lubricant may stay in the place, but it tends to dry out quickly and makes the lubricant less operative. Thus, greasing of those bearings is necessary.
Identifying the Type of Bearings
It is important to identify the type of bearings to choose the correct type of grease. There can be different types of bearings such as plain bearing, bearing with rolling elements, etc. Plain bearings do not need to be lubricated frequently whereas bearings with rolling elements need frequent regreasing.
Guide to Choose the Correct Lubricant for Bearings
Below stated are the 5 important steps that can help in choosing right grease for the bearings and gear systems:
- Knowing the Type of Bearing Grease: It is important to know the type of bearing grease required for a particular application. Usually, there 3 types of lubricant available in the market:
- PTFE: PTFE coatings can only be applied to plain bearings. They are supplied by manufacturers and do not need re-greasing frequently. It also requires less amount of maintenance.
- Lubricant with Grease: This grease is ideal for open and sealed bearings. Sealed bearings are only needed to be re-greased except for the bearing units. Those bearing units are also greased in difficult operating conditions such as high temperatures or a polluted environment. The open bearings need to be re-grease regularly. They are not filled from the factory and need to be filled manually with the chosen lubricant after their installation.
- Lubricant with Oil: Lubricant with oil is often used for gear boxes and gear units. It is also used for bearing houses in difficult conditions such as high speed of rotation and high temperatures. Oil is considered an ideal lubricant for these types of situations.
- Checking the Basic Requirements of the Lubrication: Lubricant is a mixture of 3 main substances i.e., Base oils, Thickening agent and Additives. The proportion of base oil in these lubricants is 70-90%, the proportion of thickening agent is 5-30% and the proportion of additives is 1-5%. It is important to fulfil all 3 requirements of lubrication to extend lifespan of the oil, to receive protection from wear and corrosion and to promote efficiency of the system.
- Knowing the Viscosity Value of the Base Oil: The viscosity value of base oils is used to determine the overall performance of oil during certain temperatures, speed and loading conditions. The higher this value, the thicker is the grease, whereas the lower this value, the thinner is the grease. It is important to choose the correct viscosity value index as choosing the wrong one may lead to friction and overheating of the bearings. Few aspects that should be considered while choosing the right viscosity index value are temperature, load rating, rotation speed, situations like high speed and low temperature and high load rating and high temperature.
- Select the Type of Grease: Lubricants are mostly based on two components- mineral oil and chemical thickening agent. Chemical thickening agent lubricants are also known as soap skeletons. Some of the common lubricants are lithium grease, sodium grease, calcium grease and mixed grease. Those greases can be categorized into two types- Complex grease and soap-free grease. Some of the factors to keep in mind while choosing that grease are dropping point, temperature suitability, speed, mechanical stability, resistance to pressure and water.
- Choosing the Right Lubricant: While choosing the right lubricant, few aspects to be considered are the medium rotational speed, medium temperature, load rating in ambient temperatures, continuous bearing of temperature, radiation resistance, low ambient temperature, frequent on and off of the switches, situations in food industry, biodegradability and low toxicity.
Various Correct Lubrication Method for Different Situations
There are two types of lubrication methods- Manual and Automatic. Many people choose manual lubrication for their product. However, in some situations, automatic lubrication is more reliable and preferable. Below stated are some of the situations that require specific kind of lubrication method:
- Machines with sealed bearings require manual lubrication with a cordless grease gun or a grease pump.
- Machines with open bearings require the same above state method.
- Machines with a large number of bearings require manual lubrication with a grease gun or a grease pump.
- Miniature bearings and instrument bearings require manual lubrication in clean conditions.
- Situations such as machines with difficult reaching points, industries with huge amounts of lubrication points and lubrication frequencies, machines with lubrication points behind safety cage and machines with lubrication points at a great height require automatic lubrication.
Lubrication at the Right Time
It is not advisable to wait too long to grease the bearings. Greasing the bearings increases the life of the bearings by reducing the risk of dirt and defect. Though, it is difficult to determine the correct time for greasing, below stated are some of the indications that it is a right time to grease the bearings:
- The temperature of bearings while the machine is in use.
- The number of hours the machine has been used for in terms of per day.
- The size of the bearings
- The rotational speed of the bearings.
Take Away
This is the brief explanation about Teflon grease, the five essential tips for choosing the right grease and different kinds of lubrication methods suitable for different situations. We hope this information will be effective for you. Please let us know through your valuable feedback and the suggestion in the drop box.