What type of bearing provides better sealing against lubricant loss?

Sealed bearings are designed specifically to retain lubricants and prevent contaminants from entering the bearing's inner workings. The sealing mechanism creates a barrier that effectively keeps the lubricant in place, reducing the chance of leaks that can occur with non-sealed or open bearings. This is particularly important in environments where dust, dirt, or moisture can compromise the integrity of the lubricant, leading to increased wear and potential failure of the bearing.

In contrast, non-sealed and open bearings lack this protective feature, which allows lubricants to escape more freely and contaminants to enter, resulting in a higher risk of degradation and operational inefficiency. While plain bearings do have their own set of advantages, they do not inherently provide the same level of sealing against lubricant loss that sealed bearings do. Therefore, sealed bearings are the optimal choice for applications where maintaining lubricant integrity is critical for performance and longevity.