Luoyang Dahua is specialized in manufacturing crushing machines used in sand production line. The problems appeared in the working process will affect the production efficiency, such as overheating of bearings. Dahua will analysis the above situation and provide solutions.
The causes of overheating of bearing are as following aspects:
1. Small gap in bearings will cause the over temperature rise of bearing.
2. Improper use of lubrication oil. The higher or lower viscosity of oil is not easy to form oil film, which causes overheating of bearing. Especially in higher viscosity, it not only increases the inner friction among the oil molecules, but also increases the friction between oil and metal, thus causing over heat.
3. Wrong installation. The rubber plate of couplings with big thickness, strong stiffness and lack deflection will cause more friction and heat.
4. More oil mass that reach or pass the bottom ball or the centerline of pin roller, or not meet the specification of oil usage will cause more heat during constantly stirring. Because of small heat radiating area of shell, the heat cannot release in time, and the bearings cannot realize balance in the required temperature, so the temperature is always keep high.
Solutions:
1. Adjust bearing gap to reach the specified requirement.
2. Align the concentricity of motor and crusher rotor < 0.5mm. Check the level of motor rotor and crusher rotor by placing the level gauge on the shaft neck of two bearings in the motor, fly wheel and bearing outer race, and then recheck it with leveling pipe, or take the method of hanging plumb to review the straightness of the centerline of motor and crusher.
3. Reduce the stiffness during the connection of motor and rotor. That is unloading some pieces of rubber plate on the rubber coupling, which ensures the deformation caused in the process of operation can be absorbed timely by the rubber plate to reduce the friction and additional force on the bearing.
4. Select proper lubrication oil and reasonable oil capacity. N68 EP gear oil used as the substitute of the original N150 medium-load EP gear oil, and the oil capacity keeps under the center line of the bottom pin roller, namely oil level ≦105mm. Restart the crusher, only the temperature of bearing remains below 70℃, and not higher than 70～80℃ is regard as in the normal condition.