Analysis of the influence of filler selection and pouring process on support stiffness and early failure risk in the installation of cone crusher lining plate

In the installation of wear-resistant lining plates (rolling bowl walls, crushing walls) in cone crushers, the filling material (commonly known as "filler") and its construction process located between the back of the lining plate and the main cone of the machine are key factors affecting the working performance and service life of the lining plate. Its function is far from simply "filling gaps", but directly determines the support stiffness, stress distribution, and impact load resistance of the lining plate. Improper selection or construction can significantly increase the risk of lining deformation, cracking, and even detachment.

1、 Core functions and performance requirements of fillers

Fillers mainly undertake three major functions:

Uniform stress transmission: The high-frequency and high amplitude impact force generated during the crushing of materials is uniformly transmitted from the lining plate working surface to the more robust cast steel parts of the machine body, avoiding local stress concentration.

Provide full surface support: Compensate for micro mismatches caused by machining tolerances and deformations between the back of the liner casting and the casting surface of the machine body, achieving nearly 100% contact area.

Damping buffer: to a certain extent, it absorbs and attenuates vibration energy, protecting the main engine threads, mating surfaces, and other structures.

Therefore, qualified fillers need to have sufficient compressive strength and stiffness, good flowability and filling properties, a thermal expansion coefficient similar to that of metals, and reliable curing/solidification stability.

2、 Comparison of Characteristics of Common Filler Types

The currently widely used materials are zinc based alloys and epoxy resin based composites, with significant differences in their characteristics.

Characteristic dimension: Zinc based alloy (traditional), epoxy resin composite material (modern)

The material is essentially a metal alloy (mainly Zn Al Cu series), which is formed by solidification after melting and pouring. Polymer composite materials (epoxy resin+mineral fillers) are cured and formed through chemical reactions.

High compressive strength/stiffness. Having an elastic modulus close to that of metals, it can provide very solid rigid support. Adjustable. Through formula design, its compressive strength and modulus can be adjusted within a large range, usually designed as a high-strength medium modulus, balancing support and minimal stress buffering.

Excellent liquidity. In the molten state, it has excellent fluidity and can fill extremely complex and narrow gaps. Dependent on formula. During construction, it is in a viscous fluid state and needs to be filled by its own weight and pressure flow. The filling capacity for complex structures needs to be designed specifically.

The solidification/shrinkage characteristics of metals have a relatively large solidification shrinkage rate (about 1-1.5%). If not controlled properly, shrinkage cavities or micro gaps may occur inside or at the bonding surface. The curing shrinkage rate is small (usually<0.5%), which can be formulated as a micro expansion system, making it easier to achieve dense filling.

High temperature resistance. The melting point is about 380-420 ° C, and the performance is stable at operating temperature without aging problems. There is a clear upper limit for working temperature (usually long-term tolerance ≤ 120-150 ° C). Excessive temperature can lead to a decrease in strength and aging.

The complexity of construction requires specialized melting and pouring equipment, high operating temperatures, safety risks, and the need for reheating and melting during disassembly. Construction at room temperature, mixing according to proportion is sufficient, with simple tools, safe and convenient. After solidification, dismantling requires crushing and cleaning.

If the preheating before pouring is insufficient and the pouring process is improper, it is easy to produce air holes, slag inclusions, or poor bonding with the substrate, forming "hard spots" or voids. If the mixing ratio is incorrect, the curing is insufficient, or the ambient temperature is too low, it can lead to insufficient strength, delamination, or early creep.

3、 Key control points and their impact on pouring process

Regardless of the type of filler chosen, strict construction techniques are a prerequisite for ensuring its performance. The main risk points and impacts are as follows:

Contact surface pretreatment

Requirement: The back of the lining plate and the surface of the machine body must be thoroughly cleaned, dry, free of oil stains, and rust. Usually, sandblasting (shot) treatment is required to expose the natural color of the metal and preheat to remove moisture (zinc alloy requires preheating to above 100 ° C, epoxy resin requires above dew point temperature).

Risk: Surface contamination or moisture can form an isolation layer, severely weakening the bonding strength and causing the filler layer and metal to have "two skins", resulting in support failure.

Gap control and sealing

Requirement: Special tools or gaskets should be used during installation to ensure that the filling gap between the lining plate and the machine body is uniform and meets the recommended value of the filling manufacturer (usually 3-8mm). All edges must be reliably sealed with heat-resistant sealing materials to prevent leakage during pouring.

Risk: The gap is too small, causing the filling material to be unable to flow in or difficult to compact; If the gap is too large, the amount of filler used will be large, and shrinkage or stress problems will become prominent. Inadequate sealing leads to leakage, resulting in incomplete filling areas.

Preparation and pouring of filling materials

Zinc alloy: It is necessary to strictly control the melting temperature, prevent overheating and oxidation, and fully remove slag. Pouring should be continuous, fast, and seamless, often injected from the bottom to facilitate exhaust.

Epoxy resin: It is necessary to accurately measure the A/B components, mix them thoroughly with a dedicated mixer until the color is uniform, and complete the pouring within the operating time. It is advisable to inject from a high point and use gravity to naturally exhaust.

Common risk: Interruption of pouring may result in cold joints; Uneven mixing or introduction of bubbles can lead to internal defects; Ineffective exhaust will form pores. These defects will become sources of stress concentration, expanding under impact loads, leading to the loss of local support and rupture of the lining plate.

Curing/solidification process control

Requirement: Epoxy resin should be allowed to stand at the recommended temperature for sufficient time to achieve complete curing. Zinc alloy needs to be naturally cooled to avoid cracking caused by forced cooling.

Risk: Premature use (insufficient curing/solidification) or inadequate ambient temperature, failure of fillers to reach design strength, plastic deformation or crushing under high load, resulting in loose lining plates.

4、 The comprehensive impact on support stiffness and early failure risk

Supporting stiffness: Zinc alloy can provide rigid support similar to that of cast steel, with high dynamic stiffness, suitable for extremely high impact load conditions. High performance epoxy resin can provide a "primarily rigid, slightly damped" support, and its slight elastic deformation helps to homogenize some peak stresses.

Early Failure Risk:

Uneven support and stress concentration are the most common causes of failure. Whether it is defects inside the filler (such as pores and shrinkage) or poor bonding surfaces, they can cause local areas of the lining plate to become suspended. Under the tremendous crushing force, these "weak points" will first crack and rapidly expand, causing the lining plate to fracture.

Overall looseness: If the strength of the filler is insufficient, the curing is poor, or the bonding force with the metal is poor, creep or peeling will occur under long-term alternating loads, resulting in overall looseness of the lining plate, which not only exacerbates its own wear, but also damages the main engine threads and mating surfaces.