Analysis of the necessity of cleaning and leveling the mating surface during the installation of lining plates

The installation quality of the lining plate (rolling bowl wall and crushing wall) of the cone crusher directly affects the stability of equipment operation and the service life of the lining plate. During the installation process, cleaning the mating surface and ensuring that the lining plate is level and aligned are two fundamental and critical steps. If these two tasks are not done properly, it will lead to a series of chain failures. This article systematically elaborates on the necessity of these two installation requirements based on on-site practice and fault case analysis.

1、 The force characteristics of the lining plate during operation

Before understanding the installation requirements, it is necessary to first understand the working status of the lining plate. In the process of crushing materials in a cone crusher, the moving cone liner plate undergoes both slow rotational motion and lateral stroke motion along with the eccentric sleeve. The crushing load acting on the liner plate is relatively large, with both circumferential and radial loads.

The large block shaped material is crushed during the rotation and lateral stroke of the moving cone, so the lining plate is subjected to high-frequency and alternating impact loads. This complex stress condition requires a high level of coordination between the lining plate and the cone - a tight and uniform overall contact must be achieved in order to effectively transmit the crushing force.

2、 The hazards of uncleaned mating surfaces

1. Causing the lining plate to not fit tightly with the cone

When installing the lining plate, if the contact surface between the moving cone and the moving cone lining plate is not cleaned thoroughly, there may be rust layers, rust proof layers, burrs, scratches or debris, which will prevent the lining plate from tightly fitting with the cone.

According to the technical requirements, after the installation of the lining plate, a feeler gauge should be used to check whether it is tightly attached to the cone along the mating surface, and the gap should not exceed 0.25mm. When there are debris on the mating surface, the local gap will exceed the standard, forming a hollow area. These hollow areas cannot effectively transmit pressure during the crushing process, resulting in a deterioration of the stress state of the lining plate.

2. Causing the lining plate to loosen

The direct consequence of loose coordination is that the lining plate becomes loose during operation. Under the continuous impact load, the parts with gaps will experience relative displacement, causing micro motion wear between the lining plate and the cone.

Once the lining plate begins to loosen, the impact load will further intensify the gap expansion, forming a vicious cycle. Loose lining not only affects the crushing effect, but may also damage the contact surface between the cone and the lining, increasing maintenance costs.

3. Reduce the effectiveness of filling materials

For installation methods that require filling with zinc layer or epoxy resin, the cleanliness of the mating surface directly affects the filling effect. If there are oil stains or debris on the surface, the filling material cannot form a strong bond with the metal surface, and is prone to detachment or cracking during the crushing process, losing its filling and supporting function.

3、 Specific damages caused by non leveling and correction

1. Uneven distribution of load on the lining plate

If the lining plate is not leveled and adjusted during installation, it will be biased towards one side, which will result in uneven load distribution around the lining plate when it is broken.

The lining plate should be in a central symmetrical position inside the crushing chamber. If the installation is skewed, the gap between different areas of the lining plate and the fixed cone lining plate will be inconsistent. During operation, the side with a smaller gap will experience excessive crushing force, while the side with a larger gap will experience insufficient force. This biased load state causes stress concentration in the local area of the lining plate, accelerating wear and damage in that area.

2. Increased risk of lining plate rupture

The direct consequence of uneven load is that the lining plate is prone to rupture and failure. Multiple on-site cases have shown that cracking caused by improper installation of lining plates often occurs in the early stages of use.

Research has shown that when the lining plate is biased towards one side, the area subjected to higher loads may exceed the fatigue limit of the material, resulting in cracks and propagation under cyclic impact, ultimately leading to fracture. Compared with uniform wear, local overload caused by partial load causes more severe damage to the lining plate, often resulting in abnormal failure.

3. Decreased crushing efficiency

Improper installation of lining plates can also alter the geometric shape of the crushing chamber. The crushing chamber is designed based on the principle of material crushing, and the deviation of the lining plate position will destroy the ideal crushing chamber shape, affecting the flow and crushing process of materials in the chamber.

In this case, even if the lining plate does not immediately rupture, it will still affect production efficiency due to a decrease in the crushing effect. Some materials may be discharged without sufficient crushing, resulting in an unreasonable particle size composition of the product.

4. Causing increased equipment vibration

Improper installation of the lining plate can also lead to uneven overall force distribution on the dynamic cone. During high-speed rotation, the unbalanced crushing force will be transmitted to other components of the equipment, causing increased vibration of the entire machine.

Vibration not only affects the crushing effect, but also accelerates the wear of other parts of the equipment, such as spherical bearings, transmission gears, etc., shortening the service life of the whole machine.

4、 The comprehensive consequences of improper installation

Overall, the installation defects of unclean mating surfaces and lack of leveling and alignment can trigger a series of chain reactions:

Unclean fitting surface → loose fitting → loose lining plate → micro motion wear → damage to lining plate and cone

Uneven leveling and correction → Uneven load distribution → Local overload → Crack generation → Lining plate rupture

In a practical case, a certain factory had defects such as loose fit during the installation of the dynamic cone lining plate, unstable welding of the cutting ring, failure to tighten the locking screws properly, and improper installation of the lining plate. In addition, on-site iron problems caused the lining plate to easily break and fail during use, resulting in low crushing efficiency and increased production costs.

After taking measures (including thorough cleaning of the mating surface, leveling and aligning of the lining plate, and tightening of the locking screws), the lining plate can be used stably for half a month, crushing 100000 tons of ore and significantly reducing malfunctions.

5、 Correct installation specifications and requirements

According to equipment requirements and on-site practical experience, the installation of lining plates should follow the following specifications:

1. Requirements for surface treatment of mating surfaces

Before installation, it is necessary to check the mating surface between the cone and the lining plate, and grind off any scratches or burrs

Clean the rust proof layer on the new lining plate to ensure a clean surface

For surfaces that require filling materials, lubricate or dry them according to the process requirements

2. Leveling and straightening requirements

After the new lining plate is in place, it must be aligned with the cone before tightening the pressure cap

The alignment can be checked by measuring the distance between the pressure cap and the cutting ring. If the distance is not equal, it needs to be adjusted

Use a feeler gauge to check the fit clearance around the perimeter, which should not exceed 0.25mm

3. Tightening requirements

The locking screw must be tightened in place to ensure sufficient fastening strength

The cutting ring is firmly welded to the lining plate, and the weld seam is regularly inspected during operation

For installation methods that use filler solidification, sufficient solidification time (such as about 16 hours) must be ensured