The X-shaped sealing ring, also known as the star-shaped sealing ring, is an elastic sealing component with an "X" -shaped cross-section.
The following is the detailed introduction:
Structural features
Four-lip design: The X-shaped sealing ring has four sealing lips, forming a small lubrication cavity between the two pairs of lip openings. During operation, it can maintain an oil film. Compared with the O-shaped sealing ring, its friction coefficient is lower, the starting resistance is smaller, and it is less likely to "roll and twist" under reciprocating motion.
Section shape: Its section is an X-shaped non-circular one. This design makes the sealing ring stronger in resisting torsion during installation or use, less likely to flip or deform during reciprocating motion, thus avoiding sealing failure. Working principle
During installation, the X-shaped sealing ring is pressed between the two sealing surfaces, and the four sealing lips, due to elastic deformation, closely adhere to the sealing surfaces, forming the initial seal. When the system is pressurized with a medium, the medium pressure acts on the inner section of the sealing ring, pushing the four lip openings to further compress against the sealing surface. The contact pressure increases as the system pressure rises, achieving the self-compensating sealing effect of "the higher the pressure, the tighter the seal".
Materials and Properties
Nitrile Butadiene Rubber (NBR): Exhibits excellent oil resistance, wear resistance, and elasticity, suitable for medium-pressure and temperature environments, and is commonly used in hydraulic and pneumatic systems.
Fluorine Rubber (FKM): Possesses excellent high-temperature resistance and chemical corrosion resistance, capable of operating within a temperature range of -15°C to +200°C, suitable for sealing requirements in the chemical industry and high-temperature environments.
Silicone Rubber (VMQ): Has good high-temperature and cold resistance, a wide application temperature range, and complies with hygiene standards for food and medicine industries, often used in these industries for sealing.
Polyurethane (PU): High strength, good wear resistance, suitable for high-pressure and high-speed reciprocating motion environments, commonly used in construction machinery and high-pressure hydraulic systems. Main advantage
Low friction resistance: Taking NBR material as an example, the friction coefficient of the X-type sealing ring is 0.08-0.15, which is 40%-50% lower than that of the O-type ring (0.15-0.3). This can reduce wear and energy loss.
Strong torsional resistance: The X-type sealing ring allows ±15° deflection without leakage, while the O-type ring is prone to spiral failure. Problems occur when the deflection angle is typically greater than 5°.
Long dynamic life: The dynamic life of the X-type sealing ring can reach 200-500 million reciprocating movements, which is 2-5 times that of the O-type ring (50-100 million times). Application scope
Hydraulic and pneumatic systems: Widely used in hydraulic cylinders, valve groups, actuators and other equipment, they can effectively prevent the leakage of hydraulic oil or gas and reduce friction.
Rotating machinery: Such as the rotating shaft seals of pumps, compressors and other equipment, due to their torsion resistance characteristics, can effectively reduce the flipping and damage of sealing rings.
Automotive industry: Applied in hydraulic and pneumatic systems of automobiles, such as brakes and suspension systems, providing better sealing performance and durability.
Food and pharmaceutical industry: Suitable for the selection of materials that meet food and drug standards, used in sealing environments with high hygiene standards.