The flow line of the CYSD 5204ZZ bearing lubricant is at the edge of the inner ring of the Angular Contact Ball Bearings. It is difficult to obtain the lubricating oil at the contact point with the large end face of the roller, and the lubricating part of this part needs more lubricating oil. Therefore, the CYSD 5204ZZ bearing rib is on the outer ring, so that the CYSD 5204ZZ bearing can lubricate the outer ring edge and the roller surface contact part, and at the same time can store lubricating oil even when it is at rest, avoiding the burn accident of the CYSD 5204ZZ Angular Contact Ball Bearings when starting. In order to avoid the oil discharge channel, the power loss and temperature rise of the oil agitation will be too high. The CYSD 5204ZZ bearing inner diameter and outer diameter thickness is 20x47x20,6 mm, which is twice the performance of the ordinary structure. Since the inner ring has no ribs, the CYSD 5204ZZ has a reduced temperature, which reduces the possibility of creep between the inner ring and the shaft. The CYSD 5204ZZ bearing adopts the outer ring guiding mode so that the cage can guide the roller to run smoothly without skewing, avoiding vibration and excessive wear, which is also beneficial to the high speed operation of the CYSD 5204ZZ bearing.