How to Choose Sealed Spherical Roller Bearings for Elevators?

Sealed spherical roller bearings are widely used in various industries, including elevators. They are known for their high load capacity and resistance to shock loads, making them an ideal choice for elevator applications. In this article, we will discuss how to choose the right sealed spherical roller bearings for elevators.

What Are Sealed Spherical Roller Bearings?

Sealed spherical roller bearings are a type of rolling-element bearing that features two rows of symmetrical barrel-shaped rollers. The inner ring has two raceways, while the outer ring has a common spherical raceway. This design allows the bearing to accommodate misalignment between the shaft and housing, making it suitable for applications with high radial loads and moderate axial loads.

Why Are Sealed Spherical Roller Bearings Used in Elevators?

Elevators are used to transport people and goods between different floors of a building. They require reliable and efficient components to ensure smooth operation and passenger safety. Sealed spherical roller bearings are commonly used in elevator applications due to their ability to handle high loads, shock loads, and misalignment. The sealing system helps protect the bearings from contaminants and retain lubrication, extending their service life and reducing maintenance requirements.

How to Choose Sealed Spherical Roller Bearings for Elevators?

Consider the Load Capacity

When selecting sealed spherical roller bearings for elevator applications, it is essential to consider the load capacity requirements. Elevators experience a combination of radial and axial loads due to the weight of the cabin, passengers, and goods. The bearings must be able to handle these loads without premature failure. The load capacity of a bearing is determined by its size, internal design, and material. It is crucial to consult the manufacturer's specifications and engineering calculations to ensure the selected bearings can support the required loads.

Check the Sealing System

The sealing system is a critical feature of sealed spherical roller bearings, especially in elevator applications. The seals help prevent contaminants, such as dust, dirt, and moisture, from entering the bearing and causing damage. They also retain the lubricant inside the bearing, reducing the risk of premature wear and failure. Different sealing options are available, including non-contact seals, contact seals, and integral seals. The choice of sealing system depends on the operating conditions and the level of protection required. For elevator applications, NBR (Nitrile rubber) and FKM (fluororubber) seals are often recommended due to their excellent resistance to heat, chemicals, and wear.

Consider the Operating Temperature

Elevators operate in a wide range of temperatures, from cold environments in winter to hot conditions in summer. Sealed spherical roller bearings must be able to perform reliably across this temperature range without compromising their performance. It is essential to select bearings that are rated for the expected operating temperatures. High-temperature bearings are designed to withstand elevated temperatures without losing their load-carrying capacity or lubrication properties. They are often equipped with special heat-stabilized materials and lubricants to ensure long-term performance.

Check the Lubrication Requirements

Lubrication is essential for the proper functioning of sealed spherical roller bearings in elevator applications. The lubricant reduces friction between the rolling elements and raceways, preventing metal-to-metal contact and premature wear. It also helps dissipate heat and remove contaminants from the bearing. The choice of lubricant depends on factors such as operating speed, temperature, and load. Some sealed spherical roller bearings are pre-lubricated and sealed for life, while others require periodic re-lubrication. It is crucial to follow the manufacturer's recommendations for lubrication intervals and methods to ensure optimal bearing performance.

Consider the Mounting and Dismounting

Proper mounting and dismounting are essential for the performance and longevity of sealed spherical roller bearings in elevator applications. Correct mounting procedures help ensure that the bearings are aligned and seated properly, reducing the risk of premature failure due to misalignment or excessive preload. Improper handling during installation can cause damage to the bearing components, leading to reduced service life and increased maintenance costs. The use of appropriate tools and techniques, such as induction heaters and mechanical pullers, can help simplify the mounting and dismounting process and minimize the risk of bearing damage.

Conclusion

Sealed spherical roller bearings are an excellent choice for elevator applications due to their high load capacity, shock resistance, and misalignment capability. When selecting bearings for elevators, it is essential to consider factors such as load capacity, sealing system, operating temperature, lubrication requirements, and mounting procedures. By choosing the right bearings and following proper installation and maintenance practices, elevator manufacturers and maintenance professionals can ensure reliable and efficient elevator operation for years to come.