Summary:The selection of seals and bearings is critical to the proper functioning of rolling and rotating parts. These devices a...
The selection of seals and bearings is critical to the proper functioning of rolling and rotating parts. These devices allow linear and rotational movement while limiting friction. They also disperse stress caused by radial and axial loads. Unless properly selected and maintained, bearings and seals can fail and cause catastrophic failure. In addition to allowing for easy replacement and lubrication, seals keep harmful particles and lubricants inside the bearing.
The seals used in sealed bearings are a combination of dual lip and groove design. The double lip seals are more effective than the traditional 2RS type. They protect the bearing from leaks and contaminants and allow a full 90% of the grease fill to remain inside. O-rings are a good choice because they are durable and cost-effective. However, they must have very tight tolerances, as the grease must be lubricated regularly or else the bearing will lose its lubrication.
In addition to the seals, a sealed bearing has a molded wedge-shaped silicone rubber. They prevent most contaminants from getting into the bearing by keeping the 90% fill inside. The NHBB design is a more durable and longer-lasting alternative to the standard 2RS type. The NHBB seals also do not significantly increase the weight of the bearing. They are welded to the outer race and sit at the juncture of the ball and race. Their dual lip-sealing design also prevents water and dirt from penetrating the seal.
Mobilgrease XHP 222 and Mobilgrease XHP 221 bearings are designed with precision balls. The seals are made with high-quality silicone and mineral oil-based grease and have an R-64 hardness rating. They are durable and require little maintenance, and are relatively inexpensive to replace. They are a perfect choice for bicycles and other types of moving parts. These bearings are not waterproof but they do keep out moisture and dust, and the grease is easily accessible.
The two most common types of seals are the ABEC-3 and 2RS type. These are both a good choice for the majority of purposes. Both types of seals are very reliable and will last for many years. The ABEC-3 precision of the ABEC-3 bearing makes it ideal for high-speed machines. In the event of a bearing failure, the O-rings will protect the ball and the bearing itself from moisture.
Sealed bearings are not only durable, but they are also very efficient. They are a good choice for many applications, and you can use them in your machine. Despite their high cost, they're still more efficient than other types of bearings. In addition to their durability, they're more affordable than unlubricated ball bearings. SKF offers a wide range of products and can provide customized solutions for your needs.