01. Bearing selection: NNU895Y3 at the feed end, NNUP895Y3 at the discharge end

According to the customer's working conditions, the ball mill is composed of a cylinder, a hollow shaft, a main bearing seat, and a bearing bush. An axial force will be generated when bearing a load, and a bearing with a large bearing capacity needs to be selected. We have designed the outer spherical double row roller bearing with strong load capacity, good impact resistance, convenient lubrication, high reliability, fixed to the grinding machine, and can still work normally when moving axially. Through life calculation, there is no problem in verifying 43800 hours.

02. Design optimization:

According to the customer's working conditions:

1. The original ball mill uses the hollow shaft and the bearing bush for sliding friction transmission, and the thin grease forms an oil film for circulation lubrication. In actual use, as the material increases, the bearing bush load increases. If the heat generated by friction is not dissipated in time, it will produce "Burning tile" accident, so we improved the sliding friction of the bearing pad, adopted the rolling friction design, and designed a double row roller bearing.

2. The dry ball mill will elongate due to the high temperature of the incoming material and the temperature generated by the operation. Cause the cylinder body to move in two directions and run unstable. Therefore, the movement and fixation of the mill cylinder are designed, the inlet is designed without ribs, and the outlet is designed with double ribs, which satisfy the stable operation of the cylinder.

3. Due to its own weight and the impact of grinding steel balls and steel forgings, the cylinder is bent and deformed to produce deflection, which requires the rolling bearing to be self-aligning, otherwise the cylinder is not in the same axis, resulting in damage to the bearing. Therefore, we have designed the self-aligning requirements of the rolling bearing. The outer diameter of the outer ring of the bearing is designed in an arc shape, which solves the problem of the cylinder being out of alignment.

03. Result demonstration:

 By combining the application conditions of the equipment, we have designed a new type of ball mill bearing to meet the customer's needs. The downtime caused by the customer's "burning of tiles" fault is greatly reduced, saving users 80% -90% of lubricating oil, over 8% of electricity, and a comprehensive energy saving of over 10% -15%. The power of the electric motor used in the ball mill can be reduced by 13% -20%, and the loading capacity of the grinding body can be increased by 15% -20%, improving the operation rate of the ball mill.

More Case