Solution for rotor bearing failure of hammer crusher
Date：2019-10-28 14:03 Source：cementepcViews:
Hammer crusher is the use of high-speed rotating hammer head on the rotor body to break the material, its rotor bearing in the work to bear a lot of cyclic impact force.Due to the poor working conditions of the rotor bearing, coupled with the design, manufacture and use of improper reasons, the bearing service life only a few months, hammer crusher rotor bearing failure solution.
1. Choose reasonable tolerance fit
Under normal temperature, hammer crusher rotor bearing for surplus to cooperate, but when the bearing working temperature is above 60 ℃, that is converted to clearance fit, the journal of relative movement between the inner ring, the relative movement of the friction heat on the one hand, fuelled the rise of temperature of the bearing, on the other hand shaft neck and adhesive wear lead to premature failure of the bearing.
In order to keep the interference fit between the inner ring and the journal at a higher temperature, the tolerance fit of the journal should be selected by considering the thermal expansion of the inner ring.
On the one hand, there is enough expansion space for the outer ring when the bearing overheats. On the other hand, it can also improve the stress state of the outer ring and extend the service life of the outer ring.
2. Strengthen sealing and lubrication
Timely and correct lubrication can greatly reduce the friction resistance of hammer crusher rotor bearing and restrain the temperature rise of hammer crusher bearing. In view of the working characteristics of high-speed and heavy load of rotor bearing, molybdenum disulfide compound calcium grease (zfg-3e) should be selected to lubricate the bearing.In addition, add grease every 8 hours, change oil every 3 months, and clean the bearing and seal ring and cover with gasoline or kerosene, and timely replace the labyrinth seal cover with excessive wear gap on the bearing seat of hammer crusher.
3. Improve bearing stress
The impact load acting on the hammer crusher bearing depends on the impact on the rotor and bearing bearing bearing flexibility, increase bearing bearing bearing flexibility, will reduce the impact load acting on the bearing.Therefore, an appropriate thickness of rubber plate can be added between the bearing seat and the supporting frame to improve the bearing bearing flexibility.Because add rubber plate, increase flexibility, thereby absorb a part of vibration energy, improve the hammer crusher bearing stress condition, to extend the service life of the purpose.
4. Balance the rotor during assembly
The mass of hammer crusher rotor is large and the speed is high, the casting deviation of rotor body and the mass deviation caused by the installation of hammer head will cause unbalanced centrifugal force when the rotor rotates.This centrifugal force causes the hammer crusher to produce forced vibration, causing damage to bearings and other machinery.Therefore, the manufacturer should perform balance test on the rotor to meet the requirements of the standard.When installing the hammer head, two hammer heads with the same mass should be assembled in two positions with mutual symmetry, and the gravity of the hammer head should be well matched to balance the gravity of the hammer head, the gravity of each row in the circumferential direction of the rotor should be equal, and the axial gravity should be evenly arranged, so as to achieve the balance requirement.Replacement of hammer crusher new hammer head should also pay special attention.
The above is only to improve the hammer crusher rotor bearing early failure of part of the method, we should choose a reasonable scheme according to the production environment, if you have any questions can be at any time and we leave a message.