The eccentric shaft is the main part of jaw crusher
. The moving jaw moves reciprocating under the eccentric force of the eccentric shaft. Eccentric shaft has to bear tremendous crushing force and work for a long time, which results in wear of bearings and high temperature, and the failure of lubricating oil to be added in time will cause burning damage. Improper use or maintenance may also lead to bending or fracture. Today, I share with you the faults and solutions of eccentric shaft.
The rotating part of eccentric shaft is mainly composed of movable jaw, eccentric shaft, bearing, bearing seat, belt pulley, etc. It is the main part of power transmission.
Eccentric axis bending
Causes of failure and solutions:
1. Host rollover
In the process of hoisting the jaw crusher's main engine, rollover occurs, which makes the eccentric shaft bend under unilateral force. In serious cases, it is necessary to replace the main engine immediately and strive for new hoisting replacement.
2. Material hardness exceeding standard
If the material given is too hard, it will cause eccentric shaft bending if it exceeds the maximum range of jaw crusher. Therefore, material hardness should be controlled and suitable crusher should be selected according to the compressive strength of crushed material.
3. Elbows do not meet the standard
When this kind of situation occurs, it should be checked in many ways. It is strictly forbidden to use elbow plate and elbow pad which do not meet the design standards.
4. Improper heat treatment of eccentric shaft
When the heat of eccentric shaft does not disperse in time, it will easily lead to short-term fracture; the appropriate method at this time is to replace the new eccentric shaft and use the eccentric shaft qualified for heat treatment.
5. Long-term overload operation of main engine
It is necessary to shut down the machine in time for maintenance, adjust the working load or replace the suitable crusher.
Eccentric shaft and cone sleeve loosening
Causes of failure and solutions:
1. Change the screw direction of flywheel end seal sleeve and taper sleeve
Because the sealing sleeve moves to the end of the pulley when the thread is right-handed, the taper sleeve at the end of the pulley will not loosen, so the thread direction of the pulley does not need to be changed. After the flywheel end seal sleeve and the taper sleeve thread are changed from right-handed to left-handed, when the eccentric axis rotates counter-clockwise, due to the inertia force, the sealing sleeve moves to the direction of the flywheel and tightens the flywheel, in turn, the flywheel end cone is tightened. The sleeve is firmly fastened on the eccentric shaft, so that the cone sleeve does not loosen on the eccentric shaft.
2. Repairing Eccentric Axis and Cone Sleeve Fitting Surface
Increase the contact area, surfacing the worn eccentric axle and taper sleeve with electric welding, grinding the mating surface after rough and fine turning. The grinding method is to place the repaired taper sleeve on the mating surface of eccentric axle, use 400 mesh diamond as grinding medium, grind for 0.5 h at a time, clean the diamond and print on it, if it is not qualified, check it again with the method mentioned above. Grind until it meets the requirements.
3. Repair worn flywheel end surface
A svedala jaw crusher in a factory has a 100 mm short sleeve on one side of the flywheel because of the wear and tear of the contact face between the flywheel and the seal sleeve.
Eccentric shaft wear
The main wear forms of eccentric shaft are serious wear of journal and eccentric section journal, excessive bending of axis and fatigue fracture. If the axle is straightened and replanted, the repair process is very complicated, and the repair quality is not easy to guarantee. Therefore, it is seldom used. If such a phenomenon occurs, only scrap or use the material of the shaft for other purposes.
Causes of failure:
1. The internal clearance of the bearing has not been calibrated.
2. During the production process, the crushed stone and powder produced by crushing materials enter into the bearing and cause wear and tear.
3. The lubrication work is not in place.
If the wear is serious, the eccentric shaft should be replaced in time; if the wear is slight, the bearing can be re-turned on the lathe to achieve the correct geometric shape. It is also the most important thing to do well the lubrication work of bearings, reduce the overload work of equipment and reduce the wear degree of bearings.