What Is a Seal Tapered Roller Bearing?

A seal tapered roller bearing is a type of lubricant-sealing device that is typically installed on a rotating or rolling shaft or part. It has a dual purpose: to retain the lubricant inside the bearing while also keeping it out of reach of dirt and other contaminants that could be present in or near the gap between the two parts.

Tapered roller bearings are a popular option in many applications because of their high surface-area contact and large load capacity. They are used in a wide range of industrial equipment, and they have an important role in preventing friction and reducing wear in the shaft.

The most common application for a tapered roller bearing is on the shaft of transmissions and rotating axles, where they are used to transfer torque evenly across the shaft and to prevent damage caused by friction. They are highly durable and can usually run maintenance free for hundreds of thousands of miles.

To maintain its effectiveness, a tapered roller bearing needs lubrication to dissipate heat and dampen operational noise. Oil and grease are commonly used, but other types of lubricants may be included to better meet the specific requirements of the application.

Greases are best for moderate or high RPMs, while oils are better suited to lower speeds. Grease-lubricated bearings tend to be more durable and have higher operating speeds than oiled-lubricated bearings.

The design of a tapered roller bearing is based on a bearing ring with an inner ring and an outer ring that are both tapered. The outer ring is called the cup, and the inner ring is referred to as the cone.

This design enables the bearing to handle heavy radial and axial loads as well as large amounts of misalignment or dynamic angular defects. This means that the bearing can tolerate certain angular misalignments and a large moment load, such as when changing a wheel or axle assembly.

In addition, the outer ring has a cone back face rib that guides the rollers and limits rotational motion. This design also limits friction and can withstand a large amount of vibration, which is particularly useful in automotive or other transportation applications where wheels are individually sprung and driven.

When determining the size of a bearing, it is crucial to consider factors such as its reference speed, limiting speed, and bearing torque. These values are dependent on the size of the bearing, its cage material, and the lubricant.

It is essential to choose a lubricant with good compatibility with the cage material. This is especially true of lubricants with a synthetic oil base or those that contain a high proportion of EP additives.

The lubricant should also be compatible with the temperature conditions and environment of the application, as plastics can degrade rapidly at high temperatures. This requires strict adherence to the specified oil change intervals.

Using labyrinth seals is another effective way to reduce the amount of lubricant that enters the gap between the seal and the ring of the bearing. They are made up of a series of separate pieces that interlock and create a thin, grooved path that is difficult for contaminants to follow.