How much do you know about the causes and solutions of Type 3 eccentric shaft failures of jaw crushers?

The eccentric shaft is the main part of the jaw crusher. The movable jaw reciprocates under the action of the eccentric force of the eccentric shaft. The eccentric shaft has to withstand huge crushing force. Long-term operation will cause bearing wear and high temperature. Failure to add lubricating oil in time will cause burning damage. Improper use or maintenance may also cause bending or breakage. Today, the editor will share with you the common faults and solutions of eccentric shafts. Eccentric shaft rotating part: mainly composed of movable jaw, eccentric shaft, bearings, bearing seats, pulleys, etc. It is the main part of transmitting power.

Eccentric shaft bending

Failure causes and solutions: 1. The host rolls over

When the main engine of the jaw crusher rolls over during the hoisting process, causing the eccentric shaft to bend due to stress on one side, in severe cases, it should be replaced immediately and a new main engine should be lifted.

2. Material hardness exceeds standard

If the given material is too hard and exceeds the maximum crushing range of the jaw crusher, it will cause the eccentric shaft to bend; therefore, the hardness of the material should be controlled, and a suitable crushing machine should be selected according to the compressive strength of the crushed material.

3. The toggle plate does not meet the standards

When this situation occurs, multiple assessments should be made, and the use of brackets and bracket pads that do not meet the design standards is strictly prohibited.

4. Improper heat treatment of eccentric shaft

When the heat of the eccentric shaft is not dissipated in time, it is easy to cause short-term breakage; at this time, the appropriate method is to replace the eccentric shaft with a new one and use an eccentric shaft with qualified heat treatment.

5. The host is overloaded for a long time

The machine should be shut down for maintenance in time, the working load should be adjusted or a suitable crusher should be replaced.

Causes and solutions for loosening of eccentric shaft and taper sleeve:

1. Change the thread direction of the flywheel end sealing sleeve and taper sleeve

Because when the thread is right-hand, the sealing sleeve moves to the pulley end, and the taper sleeve at the pulley end will not loosen, so the thread direction of the pulley end does not need to be changed. After changing the threads of the flywheel end sealing sleeve and taper sleeve from right-hand to left-hand, When the eccentric shaft rotates counterclockwise, due to the action of inertial force, the sealing sleeve moves toward the flywheel and presses against the flywheel. In turn, the taper sleeve at the end of the flywheel is firmly pressed against the eccentric shaft so that the taper sleeve does not loosen on the eccentric shaft. .

2. Repair the mating surface of the eccentric shaft and the tapered sleeve

Increase the contact area, surfacing the worn eccentric shaft and taper sleeve with electric welding, and grind the mating surface after rough turning and fine turning. The grinding method is: place the repaired taper sleeve on the eccentric shaft mating surface. , use 400 mesh emery as the grinding medium, grind for 0.5 hours at a time, clean the emery, apply oil stamp for verification, if it is unqualified, use the above method to grind again until it meets the requirements.

3. Repair the worn flywheel end face

A certain factory's jaw crusher, due to the flywheel and sealing sleeve

The contact surface was 100mm worn, so a 100mm long short bushing was installed on one side of the flywheel.

Eccentric shaft wear

The main wear forms of the eccentric shaft include severe wear of the journal and the eccentric section journal, excessive axis bending and fatigue fracture. If the shaft is straightened and corrected and the broken shaft is replanted and repaired, the repair process is very complicated, and the repair quality is not easy to guarantee. Therefore, it is rarely used. If such a phenomenon occurs, the only option is to scrap it or use the material of the shaft for other purposes.

Reasons for the failure: 1. The internal clearance of the bearing did not reach the calibration; 2. The gravel particles and powder generated by the crushed materials during the production process entered the inside of the bearing and caused wear. 3. The lubrication work is not in place.

Solution: If the wear is serious, the eccentric shaft should be replaced in time; if it is slightly worn, it can be turned on a lathe until the bearing reaches the correct geometric shape. It is also a top priority to lubricate the bearings well, reduce equipment overload, and reduce bearing wear.