It is an O-ring conforming to the GB1235-76 standard. It is a key component on XuanGong bulldozers, ensuring equipment sealing and stable operation, and is compatible with multiple core parts of the bulldozer. There is relative movement between the mounting holes of the bulldozer pivot and the traveling frame, and the pivot box contains lubricating oil for lubrication and heat dissipation. This O-ring is often installed in the sealing structure at the mating end of the pivot and the traveling frame, firmly sealing the lubricating oil in the pivot box, preventing leakage that could affect the lubrication effect of the pivot, and preventing severe wear of the pivot due to dry friction. The traveling section of the XuanGong bulldozer is equipped with a planetary reducer, and its floating oil seal often uses this O-ring. After axial compression deformation, the O-ring exerts a clamping force on the floating ring sealing end face of the floating oil seal. Even if the sealing end face experiences uniform wear, the stored elastic energy can be gradually released to achieve axial compensation, thereby ensuring the dynamic sealing effect of the reducer end face and preventing internal lubricating oil leakage and the entry of external impurities. Hydraulic components such as the hydraulic cylinders and pumps of a bulldozer are core power output structures. This O-ring seal can be used for the reciprocating sealing of the piston in the cylinder, preventing hydraulic oil leakage during piston movement and ensuring stable hydraulic system pressure. It can also be used for static sealing at hydraulic line joints and pump body connections, preventing hydraulic oil leakage that could lead to insufficient equipment power. Besides the core transmission and hydraulic systems, it can also be used in bulldozers in areas requiring gas-liquid isolation, such as fuel line interfaces and cooling system pipe connections. This prevents fuel and coolant leaks that could waste resources and cause equipment failure, and also blocks dust, mud, and other impurities from entering the pipes, reducing the risk of pipe blockage and component corrosion.