How does Thrust Bearing work? | Types of the Thrust Bearings

The bearings are used all over the world in different machines to support the moving parts and reduce friction. Metal-to-metal contact causes a lot of friction. Friction increases wear on the metal and create a grind that slowly degrades the metal. Bearings reduce friction by rolling the two surfaces together. The thrust bearing is the most famous type of bearing. These bearings are usually used to carry axial loads. This article explains the different aspects of the axial load.

What is a thrust bearing?

A thrust bearing is a type of bearing designed to carry the axial load and reduce friction between the moving parts. During operation, the moving components of the machine move with the thrust bearing motion that is intended to allow and support rotation about a fixed axis.

Thrust bearing

The main function of a thrust bearing is to transmit the axial load applied to the shaft, prevent the shaft from moving axially, and reduce the friction between the moving parts.

These types of bearings are usually installed around the shaft but against the elevated thrust collar. This thrust collar ensures the precise transportation of the axial loads from the shaft to the bearings. In most cases, the thrust collar is used in pairs placed on either side of the thrust collar.

Working of Thrust Bearing

Maximum types of thrust bearings use balls to support the loads. The thrust ball bearing contains small metal balls in the band around them.

These types of bearings are usually installed to support the axial loads. The placement of the balls helps to rotate the moving parts of the machine.

The thrust bearings have many other types. The cylinder bearing is one of the most famous types of thrust bearing. These bearings have cylindrical-shaped rollers facing the shaft.

Magnetic thrust bearings live up to their namesake by generating a magnetic field. These bearings are constructed by ferromagnetic materials that create a magnetic field. This magnetic field assists in carrying axial thrust.

Types of Thrust Bearings

Thrust bearing supports the loads acting in the same direction as the shaft. The thrust bearings have the following types:

  1. Thrust ball bearings
  2. Thrust roller bearing
  3. Cylindrical roller bearing 
  4. Tapered roller bearing
  5. Spherical thrust roller bearings 

1) Thrust Ball Bearings

These bearings use for applications with low thrust and very low axial loads. They use to provide high performance. These bearings have two types:

  1. Single direction
  2. Double direction

Thrust ball bearing

Read More: Working and Types of Ball Bearings

2) Thrust Roller Bearing

The thrust roller bearings are usually employed in applications that need to support high-capacity loads.

Thrust Roller Bearing

3) Cylindrical Roller Thrust Bearing 

They have excellent load-carrying ability. These bearings don’t have self-aligning ability. They have the ability to carry heavy loads.

Cylindrical Roller Thrust Bearing

4) Tapered Roller Thrust Bearing

These types of ball bearings are employed in locomotive applications. Due to the large contact area of the bearing, it withstands higher shear loads than the thrust ball bearing. These bearings are employed to support compound loads, i.e., simultaneously axial and radial loads.

Tapered Roller Thrust Bearing

5) Spherical Thrust Roller Bearings 

These bearings have the highest rated load density.

Spherical thrust roller bearings

Causes of Thrust Bearing Failure

A good quality thrust bearing is very important for the efficient working of the machine. When the bearing goes bad, it may damage the moving parts of the machine. The following are the most common causes of thrust bearing:

  1. Overloading
  2. Contaminants
  3. Misalignment

1) Contamination

Contamination is one of the common factors that lead to bearing failure. Water, sand, dirt, and airborne dust are the major causes, but corrosives and chemicals may also damage bearings.

What to look for: Please note that dents in rolling elements and races can cause vibrations.

Solution: You must properly filter the lubricant before pouring it and clean the hands, accessories tools, and workplace to lessen the risk of contamination.

2) Misalignment

Misalignment can cause extreme stress and vibration.

What to look for: The most common causes of misalignment are shaft deflections, the shaft that contains the thread, pods, or dirt on the housing shoulder or shaft, and shafts that are not perpendicular to the shaft seats.

Solution: As you note the misalignment issue, immediately stop the machine and inspect the shaft. You must inspect the system regularly, use high-precision lock nuts, and shim the housing if necessary.

3) Overloading

Bearing overload is one of the most common causes of thrust bearing failure.

What to look out for: The bearing overload looks like normal fatigue. In such conditions, extensive fatigue areas, signs of overheating, and wavy wear marks may appear on the rolling elements.

Solution: Consider reducing the load or redesigning the bearing with a higher load carry capacity.

Bearing failure can adversely affect your assets, reputation, and profits. Proper inspection and maintenance may help to extend the service life of the machine, saving the company time and money.

How to Choose Thrust Bearing?

You must choose a thrust bearing according to the design and type of the machine. You must consider the following factors when purchasing a thrust bearing.

  1. Type of Bearing: Thrust bearings have multiple designs and sizes. Choose the best size bearing that matches the machine requirements that you want to use. If your purchased bearing is too small or too large for the moving parts of the machine, your machine will not be able to use it. You may order thrust bearings of different standard and metric sizes.
  2. Bearing Material: The material of the ball is another factor that you must keep in mind while purchasing a bearing. A bearing with cheap balls may wear out rapidly. With the passage of time, the ball can lose its smooth and clean texture, which reduces the bearing performance and increases the resistance. Therefore, different materials are used to design the balls. Some of them have stainless steel balls, while others have glass balls. The stainless steel and glass balls have a long service life.
  3. Bearing Cost: You must also consider the cost of the bearing. You must choose the best suitable bearing according to your budget.

Applications of Thrust Bearings

The thrust bearings are used for the following applications:

  1. Vehicle: Thrust bearings are most commonly used in vehicles to carry the axial stresses caused by the helical gear in the latest vehicle transmission systems. These bearings are also utilized for high-speed automotive systems that need oil lubrication.
  2. Transportation: These types of bearings are also useful for the transportation industry because they improve the performance of propellers and engines.
  3. Turbines and generators: Some specific types of thrust bearings reduce drag and friction. Therefore, they are best suitable for turbines and generators.
  4. Heavy Equipment: Thrust bearings with high-rated loads are ideal for heavy-duty machines such as cranes and oil rigs.
  5. Industrial machines: Some types of industrial machines require rotating shafts. Therefore, the thrust bearing is an important part of the industrial machines.
  6. Mining and construction: Thrust bearings are usually constructed from corrosion-resistant materials that can withstand the axial loads of the machine operating in harsh mining and construction environments.

Advantages of Thrust Bearings

  • These bearings have high reliability.
  • They have simple installation.
  • They have the ability to carry high loads in harsh environments.

FAQ Section

What is the function of the thrust bearing?

The main function of the thrust bearing is to stop the shaft from roving and to transport the thrust load applied on the shaft.

What is the difference between the ball bearing and thrust bearing?

The ball bearing (also known as radial bearing) is used to support the radial load. However, the thrust bearing is only used to support the axial load.

What are the thrust bearing types?

  1. Thrust ball bearing
  2. Spherical thrust roller bearings 
  3. Thrust roller bearing
  4. Tapered roller bearing
  5. Cylindrical roller bearing 
Read More

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