High speed rotating rotor with blow bar is the main working part of impact crusher. In order to meet the requirements to crush large sized ore, the rotor should have sufficient weight and run stably.
After replacing new blow bar and assembling and repairing old blow bar, maintainers should pay attention to the balance of rotor. Here are the consequences, causes, solutions of unbalance of rotor and maintenance of the rotor.
Consequences Of The Unbalance Of Rotor
1) Unbalance of rotor will produce a large inertia force and inertia moment, which will cause the unstable operation of impact crusher;
2) The unbalance of rotor will cause greater vibration of the components, generate additional dynamic loads, destroy the normal operating conditions of impact crusher, make the bearing temperature rise too high, shorten the service life, and even cause cracks and damage to some parts.
Reasons About The Unbalance Of Rotor
1) The quality of rotor is not up to standard. The manufacturer does not strictly follow the manufacturing requirements, and the rotor is not qualified;
2) The end face of the rotor body is severely worn, and the wear is uneven, making the center of mass and the center of the rotor body are not at the same position, resulting in the static and dynamic balance of the rotor cannot be guaranteed;
3) The uneven feeding of impact crusher causes uneven force on the rotor and disrupts the balance of rotor.
Solutions About The Unbalance Of Rotor
1) Carry out balance test on the rotor before put the impact crusher into production;
2) Raw materials should fed into impact crusher evenly and continuously to avoid uneven force on the rotor;
3) When replacing the blow bar, it is best to replace it symmetrically or change the whole set, and install it correctly.
Tips For Maintenance Of The Rotor
The working conditions of impact crusher are severe, which will aggravate the wear of rotor bearing. Once the rotor fails, the cost of repair and replacement is very high, and replacement is very difficult. So, it is very important to take effective measures to increase the service life of rotor bearings in impact crusher.
Here are some tips for the maintenance of rotor:
1. choose the model of rotor bearing correctly
Double-row radial spherical roller bearings have strong load-bearing capacity and good self-aligning performance, so this type of bearing is often used as a rotor bearing in impact crusher.
2. Improve the force condition of impact crusher bearing
The impact load acting on the bearing depends on the impulse acting on the rotor and the support flexibility of the bearing seat. Increasing the support flexibility of the bearing seat will reduce the impact load on the bearing.
In this case, we can put a rubber plate with proper thickness between the bearing seat and the support frame to improve the support flexibility of the bearing seat. The rubber plate absorbs part of the vibration energy, improves the bearing force condition, and prolongs the service life of the rotor.
3. improve the balance accuracy of rotor
The rotor of impact crusher has a large mass and a high speed. The casting deviation of the rotor and the mass deviation caused by the installation of blow bar will make the rotor produce unbalanced centrifugal force while rotating. The centrifugal force will make impact crusher generate forced vibrations, causing damage to bearings and other parts. Therefore, the rotor of impact crusher need balance test before production.
Rotor is very important part of impact crusher. Correct use and reasonable maintenance can effectively avoid rotor unbalance faults and avoid unnecessary shutdowns of impact crusher.