Hub oil storage system

The invention discloses a hub oil storage system which comprises an axle head and a hub. An inner bearing and an outer bearing are mounted between the axle head and the hub. Areas for mounting the inner bearing and the outer bearing are bearing chambers, and a hub chamber is between the two bearing chambers. The outer side of the inner bearing is provided with a hub oil seal, and the outer side of the outer bearing is provided with an oil retaining ring. Lubricating grease is further stored in the hub for lubricating the inner bearing and the outer bearing. A middle sleeve is arranged in the hub and is connected with outer rings of the inner bearing and the outer bearing. The lubricating grease is stored in the bearing chambers. The middle sleeve is sleeved on a hub inner chamber between the inner bearing and the outer bearing, and the oil retaining ring is mounted on the outer side of the outer bearing, so that the lubricating grease is gathered on the inner bearing and the outer bearing, usage amount of the lubricating grease is reduced, utilization rate of the lubricating grease is increased, pollution is reduced, low-carbon environment-friendly effect is achieved, lubricating effect is evident, friction resistance is reduced, wear is relieved, and the bearings are more durable.