The thermal oxidation mechanism of oil seal aging is a key concern for heavy-duty hydraulic pump shafts operating under sustained heat and load. In high-temperature conditions, oxygen and heat act together on the elastomer compound, gradually breaking molecular chains and changing the material structure. This oxidation process causes hardening, reduced elasticity, surface cracking, and permanent deformation, all of which weaken the seal’s ability to follow shaft motion. Heavy-duty hydraulic pumps often generate significant frictional heat due to high pressure, continuous rotation, and demanding duty cycles. If cooling and lubrication are insufficient, the sealing lip is exposed to even greater thermal stress. Once oxidation damage progresses, the seal lip loses flexibility, the contact line becomes unstable, and leakage begins. Contamination ingress and shaft wear may then accelerate overall system failure. Preventing thermal oxidation requires suitable material selection, proper operating temperature control, and careful maintenance planning. Industrial seals developed for hydraulic pump shafts offer improved resistance to thermal aging, good oil compatibility, and stable sealing performance under severe conditions. These sealing products are widely used in engineering machinery, mining equipment, industrial power units, and hydraulic systems where long service life and dependable leakage control are critical.