What is required for a sealed ball bearing in terms of lubrication?

Sealed ball bearings are designed to operate efficiently under normal conditions without the need for additional lubrication during their lifespan. The seals in these bearings are intended to retain the lubricant that is initially applied during manufacturing, protecting it from contamination and preventing it from leaking out. This design allows sealed ball bearings to be low-maintenance, making them ideal for applications where regular maintenance is challenging or impractical.

In typical use, the lubricant within the sealed bearing is sufficient to reduce friction and wear, enabling the bearing to function effectively over time. These bearings can often last for years in regular conditions without requiring any further lubrication, as long as they are not subjected to extreme conditions that exceed their operational limits. This is why stating that a sealed ball bearing does not need lubrication under normal use is accurate.