What are the common faults and solutions for ball mill gears?

As one of the important components of a ball mill, gears can have a significant impact if they fail. So, what are the common faults and solutions for ball mill gears?

1. Cracking of the large gear ring of the ball mill
If the vibration of the body suddenly intensifies and the noise increases after long-term operation of the ball mill, it is likely that the ball mill has serious cracks. When the large gear ring of the ball mill has slight cracks, it should be remedied at any time. Otherwise, under long-term heavy load operation, this situation may occur, which belongs to fatigue cracks.

Handling measures:
If other parts of the large gear ring are intact and only severe cracks appear locally, local repair can be carried out. Before repair, all steel balls, materials, etc. inside the ball mill cylinder need to be removed, and then the bolts of the large gear ring should be loosened to locate the crack. Two steel plates with the same size as the cracks should be used for vertical welding at both ends of the large gear.

2. Severe vibration of the small gear of the ball mill
The normal operation of the ball mill uses an electric motor to drive the ball mill to perform rotation operations. The electric motor drives the ball mill to be directly connected to the small gear through an elastic column pin coupling and drives the large gear ring transmission to achieve the operation of the ball mill. During operation, if severe vibration is found on the small gear and its base, it is often due to the distance between the small gear and the anchor bolt, and the lack of a fixed point in the middle, which causes a large amplitude in the middle part of the small gear base. Frequent vibration can lead to severe wear of the small gear.

Handling method:
Replace the small gear of the ball mill again, and add 2 anchor bolts on the inner side of the small gear and the meshing side of the large gear, and reinforce the base again.
After homework, the foundation should be cleaned first, and the levelness and elevation of the foundation surface, as well as the position and height of the anchor bolts, should be checked. Drill diameter holes (the pore size needs to be determined according to the size of the ball mill model), place anchor bolts, and grout and pour. After solidification, use wedge iron for preliminary alignment.

3. The temperature of the rolling bearing at the feed end of the ball mill suddenly rises
During the normal operation of the ball mill, the temperature of the feed end rolling bearing suddenly rises to above 160 ℃, which has seriously exceeded the normal temperature value of the bearing (50-60 ℃). This situation is often caused by severe bearing wear, such as the deformation of the bearing rolling element due to wear, the wear of the hollow shaft outer diameter of the fixed bearing, and the reduction of the diameter, which are the main reasons for the sudden increase in bearing temperature.

Solution:
1. When the degree of wear is relatively light, welding repair can be carried out on the outer surface of the worn hollow shaft neck. The outer circle can be divided into 12 equal parts, and the welding repair surface width is 40mm, which is the length of the entire bearing installation. After welding repair, grinding can be carried out along the axial direction. Due to the conical shape of the outer diameter of the hollow shaft, the reference is set on the outer diameter of the hollow shaft that has not been worn at the shoulder. The outer diameter dimensions in all directions after repair are measured using an outer micrometer, and the straightness is measured using a gauge to ensure that the tolerance of the hollow shaft is within the designed interference fit range.

2. When the wear is severe, bearings need to be replaced. The tolerance of the new bearing should be measured first, and a test bar should be made. The tolerance size of the test bar should be 50 times larger than the outer diameter of the hollow shaft μ M. Prepare the necessary heating oil tank, temperature measuring instrument and other tools for installation, and heat the bearing. When the bearing is heated to around 120 ℃ and the test rod can smoothly pass through the inner diameter of the bearing, the bearing should be installed immediately. After installation, lubricating grease should be added in a timely manner.