In industrial transmission systems, hydraulic equipment, and special working conditions, oil seals’ performance directly determines equipment stability and service life. Under harsh environments like high temperature, oil-rich settings, high friction, and strong corrosion, these functional seals are critical to efficiency, meeting modern industrial demands for "long-term effectiveness, reliability, and complex condition adaptability" via material optimization, structural innovation, and process upgrading.
Core materials: FKM (fluororubber, -20°C~200°C, 230°C short-term), FFKM (perfluoroelastomer, -40°C~300°C for aerospace/nuclear power), VMQ (silicone, -55°C~180°C for alternating temperatures). C-F bonds in FKM resist thermal decomposition.
Temperature fluctuation ≤±5°C, lip pressure 0.3–0.8MPa, compression set ≤15% (GB/T 7759). Tensile strength retention ≥70% after 1000h at 200°C. Vibration resistance ≥10Hz.
Used in engine blocks, high-temperature valves, new energy vehicle motor controllers (≥150°C, IP67). Trends: nano-reinforcement for FKM’s 250°C+ short-term resistance; "metal skeleton + ceramic coating" to reduce heat damage.
NBR (nitrile rubber, -40°C~120°C) for mineral/hydraulic oil (volume change ≤10% after 72h immersion). HNBR (-30°C~150°C) for additive-containing hydraulic oil. FKM for synthetic oil/fuel.
Hardness change ≤±10 Shore A after 168h in 40°C mineral oil. Sealing stability at 10–30MPa (ISO 3457), no leakage after 500h at 100°C.
Applied in gearboxes, hydraulic cylinders, engineering machinery (HM/HV hydraulic oils). Upgrades: biodiesel/synthetic ester-resistant materials; lip optimization to reduce swelling.
PU (polyurethane: Shore 90A, friction coefficient 0.15–0.25, 5–10x longer life). NBR+carbon fiber composites for wear resistance/flexibility. PTFE coating cuts friction by 30% for high-speed rotation.
Wear ≤0.3mm after 2000h at ≤15m/s. Coating adhesion Grade 1 (GB/T 9286). ≥1 million reciprocating cycles, friction fluctuation ≤±10%.
Used in motor bearings, conveyor rollers, hydraulic rods (dustproof structures for dusty environments). Innovations: gradient material design; FEA-optimized lip pressure distribution.
EPDM (pH 1–13) for acids/bases/steam. FKM for organic solvents/oxidants. FFKM for concentrated acids/alkalis/strong oxidants.
Volume change ≤8%, tensile strength retention ≥65% after 72h in 5% H₂SO₄/NaOH (25°C). No cracking in toluene/acetone. 1000h salt spray resistance (no metal rust).
Used in chemical reactors, acid-base pumps, marine equipment, desulfurization systems (≥120°C). Trends: eco-friendly materials; multi-functional integration (corrosion/heat/wear resistance).
Temperature >150°C: FKM/FFKM; mineral/hydraulic oil: NBR/HNBR; high-speed/reciprocation: PU/PTFE-coated; acids/organic solvents: EPDM/FKM.
Use special tools (lip faces medium); installation gap 0.1–0.3mm. Replace on leakage or lip wear >0.5mm.
Comply with GB/T 13871.1/ISO 3457. Third-party certification; 3% batch sampling for condition tests.
These functional oil seals are core to sealing systems. Precise selection, proper installation, and maintenance ensure long-term stability. Future trends: multi-functional integration, environmental friendliness, and extended service life, supporting extreme-condition equipment operation.
