1. Feed machinery equipment accessories press roller shaft product introduction
In the process of feed processing, the pelleting process is very important, and the press roller is one of the key components in the pelleting machine. It works with the press roller to apply pressure to the material so that it passes through the ring mold to form a granular feed. The performance of the roller directly affects the quality of feed particles, the production efficiency of the granulator and the overall stability and service life of the equipment. In this paper, the feed machinery and equipment accessories press roller is introduced in detail, including its structural composition, material characteristics, manufacturing process, performance characteristics, application scenarios and maintenance points.
2. Structure composition
The press roller is usually a slender cylindrical shaft component, and its main structure includes a shaft body, a journal and a connecting end. The shaft body is the part of the press roller installation, generally has a specific outside diameter and length, and the surface is machined with a high-precision cylinder to ensure that the press roller can be stably installed on it and freely rotate. The journal is located at both ends of the shaft body or a specific position, its diameter is usually smaller than the shaft body, and the bearing seat of the granulator is matched to bear the radial support of the press roll, ensuring the stability of the shaft in the process of high-speed rotation. Depending on the design and transmission mode of the pelleter, the connecting end may be provided with a keyway, spline or other connection structure for connecting with the power source or transmission components to achieve the transfer of torque and drive the press roller and the press roll rotation.
3. Material characteristics
High quality alloy steel
In order to meet the strength and toughness requirements of the press roller under harsh working conditions such as high pressure, high speed and frequent start and stop, high-quality alloy steel materials are often used, such as 40Cr, 42CrMo, etc. 40Cr alloy steel has good comprehensive mechanical properties, after tempering treatment, hardness up to HRC28-32, can withstand a certain pressure and torque, suitable for small and medium-sized feed pelletizing machine press roller. 42CrMo alloy steel due to containing molybdenum element, its strength and hardenability is higher, after tempering and surface quenching treatment, the surface hardness can be increased to HRC50-55, with better wear resistance and fatigue resistance, widely used in large, heavy duty feed pelleting machine press roller, can effectively cope with high load working conditions, Reduce the risk of shaft deformation and damage.
Carburizing steel
For some rollers that require very high surface hardness and wear resistance, carburized steel such as 20CrMnTi is a good choice. Carburized steel through carburizing quenching treatment, the surface of the shaft to form a high hardness of carburizing layer, hardness can be as high as HRC58-62, while the heart still maintains a relatively low hardness and good toughness. This "surface hard and tough" characteristic makes the press roller in the process of frequent friction with materials and ring die, can effectively resist surface wear and fatigue pitting, at the same time under impact load, the toughness of the heart can prevent shaft fracture, extend the service life of the press roller, especially suitable for feed pelletizing machine on the particle quality and production efficiency requirements of the occasion.
4. Manufacturing process
Forged blank
The blank of the press roller is generally manufactured by forging process. The forging process can refine the grain of the metal material and make the organization more dense, thereby improving the strength and toughness of the material, and eliminating the internal defects caused by the metal in the smelting process. The blank after forging needs to be normalized or annealed to eliminate the forging stress, improve the cutting performance of the material, and prepare for the subsequent machining process.
machining
Machining is the key link in the manufacture of press roller, including turning, milling, grinding and other processes. Firstly, through turning, the outer circle, journal and connecting end of the blank are processed to the design size, and the features such as keyway and center hole are processed. In the process of turning, it is necessary to strictly control the precision indexes such as the cylindricity of shaft body, roundness of journal and surface roughness. Then the milling process is used to process some special shapes or structures on the shaft, such as the positioning plane. Finally, the key parts of the journal and shaft body are finely ground by grinding process to further improve the surface accuracy and finish, so that the combination of the journal and the bearing is more tight and smooth, and the installation of the shaft body and the press roll is more stable and reliable, ensuring the balance and stability of the press roll at high speed.
Heat treatment
Heat treatment plays a decisive role in improving the performance of the press roller. For the press roller made of alloy steel, tempering treatment is usually adopted, that is, quenching and tempering at high temperature after quenching, so that the shaft can obtain good comprehensive mechanical properties and improve the matching degree of strength and toughness. For the carburizing roller, carburizing, quenching and low temperature tempering are required. Carburizing treatment makes the shaft surface rich in high concentration of carbon elements, after quenching to form a high hardness carburizing layer, low temperature tempering to further eliminate quenching stress, stabilize the structure and size, improve the wear resistance and fatigue strength of the shaft surface. In the heat treatment process, it is very important to accurately control the heating temperature, holding time, cooling speed and other process parameters, otherwise it will easily lead to defects such as shaft deformation, cracking or uneven hardness.
Surface treatment
In order to further improve the surface performance of the press roller, surface treatment can be carried out according to actual needs. For example, the nitriding treatment can form a nitriding layer with high hardness, good wear resistance and certain corrosion resistance on the shaft surface, effectively improving the anti-bite ability and wear resistance of the shaft and the roller mating part. At the same time, the nitriding treatment temperature is low, and the influence on the deformation of the shaft is small. Hard chrome plating treatment can significantly improve the surface hardness and finish of the shaft, reduce the coefficient of friction, reduce the wear and power loss between the shaft and the press roller, suitable for some of the feed pelletizing machine roller with high surface quality and transmission efficiency requirements.
5. Performance characteristics
High strength and toughness
High quality material and reasonable heat treatment process give the perfect combination of high strength and high toughness. In the process of feed granulation, the roller needs to withstand the huge pressure from the material and the centrifugal force and torque generated by the high-speed rotation of the roller, and the high strength can ensure that the shaft does not deformation, fracture and other failure phenomena under the action of these loads. At the same time, the high toughness makes the shaft effectively absorb energy when it is subjected to impact loads, such as foreign bodies in the material or sudden equipment start and stop, to avoid instant fracture and ensure the safe and stable operation of the equipment.
Good wear resistance
Due to the close fit of the press roller and the direct contact with the material during the pelleting process and the relative sliding friction, good wear resistance is a necessary characteristic. Through the use of suitable materials (such as carburized steel, alloy steel and combined with surface treatment) and precise manufacturing process, the surface hardness of the press roller is high, which can effectively resist the wear of the material and the press roller, reduce the gap change between the shaft and the press roller, and ensure the stability of the pelleting pressure, so as to ensure the quality consistency of feed particles and the stability of production efficiency. In the course of long-term use, the pressure roller with good wear resistance can significantly reduce the maintenance cost and downtime of the equipment.
High precision and balance
The high precision machining of the roller ensures the precise fit with the roller, bearing and other parts. The cylindricity of the shaft body, the roundness of the journal and the dimensional accuracy of each part are strictly controlled within a very small range, so that the press roller can rotate smoothly and evenly on the shaft, reducing vibration and noise. When rotating at high speed, good balance can prevent the shaft from violent vibration due to unbalanced force, avoid damage to other parts of the granulator, and also help to improve the molding quality of feed particles, reduce the particle shape irregular, uneven density and other problems caused by vibration.
Stable transmission performance
As a part of the transmission system, the rational design and high-precision machining of the connecting end of the press roller ensure the effective transmission of torque. Whether it is a keyway connection, spline connection or other special connection, it can ensure that the power from the motor or reducer is stably transmitted to the press roller, which drives the press roller to rotate, so that the material is evenly and stably squeezed between the ring die and the press roller, achieving an efficient pelleting process. Stable transmission performance helps to improve the overall production efficiency of feed pelletizing machine and the stability of particle quality.
6. FAQ
Q: What is the main material of the roller?
A: The roller is usually made of high-strength steel or alloy steel to ensure that it has sufficient strength and wear resistance. These materials can withstand high loads and long periods of use.
Q: How to choose the right roller size?
A: Choosing the right roller size needs to consider the power, speed and load of the equipment. Ensure that the selected size can meet the design requirements and conditions of use of the equipment.
Q: What are the surface treatment processes of the press roller?
A: The common surface treatment process of the press roller includes quenching, carburizing and nitriding. These processes can improve the hardness and wear resistance of the surface and extend the service life.
Q: How to ensure the transmission efficiency of the press roller?
A: In order to ensure the transmission efficiency of the press roller, the coordination accuracy between the shaft and the roller should be ensured, the lubrication system should be checked and maintained regularly, and the lubricating oil should be kept clean and appropriate.
Q: What problems may occur during the use of the roller?
A: The press roller may have problems such as wear, fracture, deformation or poor fit during use. These problems are usually caused by overload, inadequate lubrication, or material defects.
Q: What are the special requirements of the roller in different application scenarios?
Answer: In different application scenarios, the press roller may have different special requirements. For example, the press roller used in high temperature environments needs to have high temperature resistance; For use in corrosive environments, corrosion-resistant materials are required.
