Tip: Oil Seal Basics
of you will already understand these basics of how an oil seal
is designed but we wanted to put this tip out for people new to
an oil seal environment there is a shaft that is rotating inside
a housing or bore. Because of friction, there must be some clearance
between the shaft and the bore. The function of the oil seal is
to stop whatever fluid is inside from leaking out the clearance
between the shaft and housing. The seal may also be used to prevent
outside materials, such as dirt, from moving in through the clearance.
sealing" is the relationship between the rotating shaft and
the seal and is handled by the sealing element. A garter spring
may used in the oil seal to increase the radial interference between
the seal lip and contact point on the shaft. In order to achieve
this interference, the oil seal's ID must be slightly smaller
than the diameter of the shaft.
sealing" is the relationship between the housing and the
seal. In order to achieve this interference, the oil seal's OD
must be slightly larger than the diameter of the housing or bore.
oil seal normally consists of three basic components: the sealing
element, the metal case and the spring. The purpose of the sealing
element is to stop the fluid from leaking between the shaft and
housing. The metal case will give rigidity and strength to the
seal while it is being held in the bore or recessed groove. The
spring will help make the sealing element more effective. All
materials must be selected depending on the environment in which
the oil seal will function.