The seal design for the stroke cannon hardware tool requires the coordinated use of multiple technologies to achieve precise gas leakage prevention. The core is to build a dynamically balanced sealing system to accommodate high pressure, high speed, and complex operating conditions. Seal design must be approached from seven perspectives: material selection, structural innovation, process control, seal type matching, auxiliary system optimization, dynamic compensation mechanisms, and simulation verification.
Material selection is fundamental to seal design. During stroke cannon operation, seals must withstand repeated impacts from high-pressure gas and high temperatures. Therefore, materials with excellent high-pressure resistance, wear resistance, and chemical stability are crucial. For example, fluororubber or perfluoroelastomer are commonly used in dynamic seals due to their low permeability and high-temperature resistance. Low-friction materials such as polytetrafluoroethylene (PTFE) can reduce frictional losses between seals and moving parts, extending their service life.
Structural innovation must focus on optimizing the seal interface morphology. Traditional rectangular-section seals are prone to leakage under high pressure due to uneven contact stress distribution. However, a drum-shaped or tapered cross-section design can compensate for manufacturing errors through elastic deformation, ensuring uniform contact between the seal surface and the cylinder wall. Furthermore, self-tightening seals utilize medium pressure to generate additional compressive force on the sealing surface. The higher the pressure, the more pronounced the sealing effect, making them suitable for ultra-high-pressure applications.
Process control is crucial for ensuring seal reliability. During seal manufacturing, dimensional accuracy and surface quality must be strictly controlled. For example, the sealing surface roughness must be below Ra0.2 to minimize fluid leakage channels. CNC milling or electro-discharge machining (EDM) techniques ensure that flow channel dimensions closely match the designed values. Assembly must also be free of rough handling. Seals should be lubricated with hydraulic oil before installation to prevent scratches that could lead to seal failure.
The matching seal type should be tailored to the specific operating conditions. Reciprocating components (such as pistons and cylinders) often utilize a combined seal structure, with O-rings providing initial preload and retaining rings or support rings dissipating lateral forces to prevent seal extrusion failure. Rotating components (such as shafts and housings) often utilize mechanical seals or dry gas seals. Dry gas seals utilize dynamic pressure grooves on the sealing surface to create an air film, achieving contactless operation and leaking rates that are only approximately 5% of those of contact seals.
Optimizing auxiliary systems can significantly improve sealing performance. For example, a pressure compensation device can be installed within the seal chamber to automatically adjust the sealing surface pressure when the medium pressure fluctuates, maintaining air film stability. For high-temperature operating conditions, a cooling water jacket or air cooling structure can be used to control the seal temperature and prevent performance degradation caused by material aging.
Dynamic compensation mechanisms are a core technology for addressing complex operating conditions. During stroke cannon operation, seal gaps may develop due to vibration, thermal deformation, or wear. In these cases, elastic elements (such as springs) or fluid pressure must be used to automatically compensate for gap changes. For example, in dry gas seals, air film stiffness can be optimized by adjusting the shape and number of dynamic pressure grooves. When external disturbances cause changes in air film thickness, the dynamic balance between the air film's reaction force and the closing force quickly restores the seal gap.
Simulation verification is used throughout the seal design cycle. Computational fluid dynamics (CFD) software is used to simulate the fluid flow within the seal chamber, predicting pressure distribution and leakage, providing data support for structural optimization. Finite element analysis (FEA) can assess stress concentration in the seal under high pressure to ensure that the design meets strength requirements. Through iterative optimization of simulation and physical testing, the success rate and reliability of sealing design can be significantly improved.
