A component of machine that seals lubricants, an oil seal is constructed of rubber, grater spring, and an internal case. While preventing the leakage of lubricants, water, or chemicals, an oil seal also prevents the entry of dust and dirt into a machine.
These seals are primarily used for rotary applications only. Oil seals have a flexible lip that rubs against a shaft or housing to prevent the leakage or contamination of fluids and debris. For proper installation, the seal lip should point towards the lubrication being contained. Some oil seals have a spring to help keep the lip in contact with the shaft. The sealing orientation and direction is important to consider for oil seals and grease seals..
Hydraulic cylinders operate in a variety of applications and environmental conditions, including exposure to dust, debris or outside weather conditions. To prevent these contaminants from entering the cylinder assembly and hydraulic system, wiper seals are fitted on the external side of the cylinder head.
Wiper seals maintain sealing contact to the piston rod when the equipment is stationary and in use, whereas the tolerance for the rod diameter is determined by the rod seal. Without a wiper seal, the retracting piston rod could transport contaminants into the cylinder. The outside static sealing of the wiper seal within the housing is also important to avoid moisture or particles from entering around the outside of the wiper seal.