The interior of a bearing is generally composed of an inner ring, an outer ring, rolling elements and a cage—usually called the four major parts. For sealed bearings, plus lubricant and sealing ring (or dust cover)—also known as the six major parts
Second, the working condition of the bearing
When the bearing is working (rotating at a certain speed), it has the ability to bear radial load or axial load.
When the bearing rotates at a certain speed, radial runout or axial runout will occur.
According to the working condition of the bearing: