4720252 SEAL OIL For HITACHI ZW220

The sealing lip design is unique, with its lip end shaped like a wedge, which presses against the surface of the shaft to achieve the sealing fluid function. Even under mechanical vibration and fluctuations in sealing fluid pressure, the sealing lip, as a flexible elastic body, can maintain a stable sealing effect and maintain the stable contact state between the lip and the shaft surface.Some oil seals, such as self-aligning pressure oil (SAPO) seals, can prevent external environmental pollution by using pressurized oil (minimum of 0.5 Bar/50 kPa) between two oil seals when the shaft bearing housing has radial, vertical, and horizontal misalignments. This can maintain a clean lubricant in the bearing housing and ensure a good sealing effect.

Oil seals are typically made up of synthetic rubber, a metal ring, and a spring, among other components. Of these, the spring helps to apply pressure to the sealing lip, maintaining that pressure; the dust lip is a secondary lip that is not connected to the spring and serves to prevent dust from entering; and the fitting section helps prevent fluid from leaking or intruding between the outer surface of the oil seal and the inner surface of the housing when the oil seal is fixed in the housing bore.The main function of a seal is to prevent lubricating oil leakage, which is very critical in various mechanical equipment, such as in the reducer of an oil pump. The seal in the reducer can prevent the lubricating oil from leaking out, thus ensuring the normal operation of the equipment. In addition to oil, modern seals can also prevent water and chemical liquids from leaking to meet the sealing requirements in different working environments. For example, in some chemical equipment, the seal can prevent chemical liquids from leaking out from the gaps in the machine to ensure the safety of the equipment and the work environment from pollution.