The sealing structure design of custom-made press piston rods is crucial for ensuring stable operation and preventing leakage in practical applications. Because custom-made products must meet performance requirements under specific operating conditions, the sealing structure design must comprehensively consider factors such as material compatibility, structural rationality, installation process, and environmental adaptability, achieving long-lasting sealing through meticulous design.
The selection of sealing materials is fundamental to preventing leakage. Custom-made press piston rods are often used in special environments such as high pressure, high temperature, or strong corrosion. Traditional sealing materials such as rubber and PTFE may not meet the requirements. In such cases, high-performance materials must be selected based on specific operating conditions. For example, fluororubber or silicone rubber can be used in high-temperature scenarios, with temperature resistance exceeding 200℃; in highly corrosive environments, polyimide or ceramic composite materials are required to resist chemical corrosion. Material selection must also consider compatibility with the piston rod and cylinder to avoid changes in the sealing surface clearance due to differences in material expansion coefficients, which could lead to leakage.
The form of the sealing structure must be matched with the motion characteristics of the piston rod. For reciprocating piston rods, common sealing structures include O-ring seals, V-ring seals, and combined seals. O-ring seals are simple in structure but prone to extrusion deformation under high pressure; V-ring seals improve sealing performance through multi-layer lip design but require precise control of installation clearance; combined seals combine the advantages of different sealing forms, for example, using PTFE support rings on the high-pressure side to prevent O-ring extrusion and rubber sealing rings on the low-pressure side to ensure flexible contact. In non-standard customization, the sealing structure layers can be flexibly adjusted according to the piston rod's stroke, speed, and pressure parameters to achieve synergy between dynamic and static sealing.
The machining accuracy of the sealing surface directly affects the sealing effect. The contact surface between the piston rod and the seal must maintain a high degree of smoothness, typically requiring a surface roughness Ra value below 0.4μm to reduce seal wear. Simultaneously, the geometric accuracy of the sealing surface must be strictly controlled; for example, using a rounded transition design instead of a right-angle transition can reduce the risk of stress concentration. In non-standard customization, surface quality can be improved through precision grinding or polishing processes, and online testing equipment can be used to monitor machining parameters in real time to ensure stable sealing surface quality. Preload control is a key parameter in sealing structure design. Excessive preload accelerates seal wear, leading to premature failure; insufficient preload fails to form an effective seal, causing leakage. In non-standard customization, finite element analysis is needed to simulate the stress distribution of the seal under different preloads, combined with experimental data to determine the optimal preload range. For example, in high-pressure applications, a spring-loaded sealing structure can be used, automatically compensating for seal wear through the elastic deformation of the spring to maintain a constant preload.
Environmental adaptability design must consider the combined effects of temperature, pressure, and media. In low-temperature environments, sealing materials may become brittle, leading to seal failure; under high pressure, seals are prone to extrusion deformation. In non-standard customization, adaptability to environmental changes can be improved by optimizing the geometric parameters of the sealing structure, such as increasing the sealing lip width or using a stepped sealing design. Furthermore, for special media, such as liquids containing particulate matter or high-viscosity greases, a dust scraper ring or guide groove should be added to the sealing structure to prevent impurities from entering the sealing surface.
The standardization of the installation process plays a decisive role in the sealing effect. When installing seals, avoid scratching, twisting, or excessive stretching. For example, O-ring installation requires a dedicated guide sleeve to prevent localized deformation caused by direct finger contact. In non-standard customization, quick-installation interfaces or modular sealing components can be designed to simplify the installation process and reduce human error. Simultaneously, pressure testing or leak detection is necessary after installation to ensure the reliability of the sealing structure under actual operating conditions.
The sealing structure design of non-standard customized press piston rods requires a multi-dimensional approach, including material innovation, structural optimization, process control, and environmental adaptation, to achieve full lifecycle management from static to dynamic sealing. This design philosophy not only improves the product's sealing performance but also provides technical assurance for the stable operation of equipment under complex conditions.
