Introduction
Typical of oil seals, the skeleton oil seal has various uses, particularly in mining, fire fighting, engineering, and crane applications. Sealing rotating or reciprocating shafts mechanically is the function of the skeleton oil seal. It forms a firm seal to stop lubricating oil or other media from leaking.
Types of skeleton oil seals
TC type: oil- and dust-proof main lip and auxiliary lip of double-lip skeleton oil seal with inner skeleton and outside rubber, ideal for dusty environments.
SC type: dust-free environment ready single-lip skeleton oil seal with outer rubber.
TF type: Usually composed of stainless steel spring and fluorine rubber material, this rubber-covered iron shell oil seal is appropriate for corrosive environments.
SF type: single lip, dust-free, similar to TF type.
Elements of the skeleton oil seal
Usually consisting of several essential parts, skeleton oil seals are intended to be fitted on rotating shafts:
Lip sealing
The section of the seal that makes direct touch with the shaft is called the sealing lip. The tight seal it is designed to provide prevents liquid leaks. Usually, flexible elastic substance makes up the lip.
Springs The sealing lip is often kept in contact with the shaft by a ring spring that provides continuous radial pressure. This somewhat offsets attrition and mild shaft misalignment.
The seal is structurally supported by a metal house. It guarantees a firm seat of the seal in the housing bore and helps it keep its form. Most often, stainless steel or steel makes up the housing.
An additional lip, also referred to as a dust lip, is a feature of some housing seals that serves to keep pollutants out of the primary sealing lip.
To enhance sealing of the housing bore and stop corrosion, the seal’s outside surface may be coated or coated with rubber.
Structures of housing seals
The materials used in the manufacture of housing seals mostly dictate their effectiveness and longevity. Operating factors like temperature, pressure, and kind of fluid being sealed affect the material used.
Among the common materials are nitrile rubber (NBR), which finds extensive use due to its well balanced characteristics, which include resistance to fuels and lubricants as well as moderate temperatures (-40°C to +120°C). It finds various industrial and automotive uses.
Excellent high temperature (up to +250°C) and chemical resistance make fluorocarbon rubber (FKM/Viton) perfect for use in corrosive fluid-containing applications and severe environments.
Good heat resistance and great flexibility at low temperatures characterize silicone rubber (VMQ). It finds utility in applications requiring a broad temperature range (-60°C to +200°C).
Polyacrylate rubber (ACM): Suitable for high-temperature oil seal applications including automobile gearboxes, ACM is renowned for its resistance to oxidation and hot fluids.
Polytetrafluoroethylene (PTFE): Able to tolerate high temperatures and has outstanding chemical resistance. It finds utility in demanding settings where conventional elastomers would fail.
Precautions for installation and usage
To prevent contamination, before installation make sure the shaft and the installation cavity are clean.
Matching of the dimensions of the oil seal, shaft, and hollow should be done precisely.
Check the oil seal’s wear often and, if needed, replace it on schedule.
Specifications for storage To avoid the oil seal deteriorating or distorting, store it somewhere dry, dust- and sun-proof.
Steer clear of damage，During installation and usage, stay away from scratching or puncturing the oil seal with sharp objects.
Conclusion
Selected and installed correctly, skeleton oil seals guarantee mechanical equipment’s dependability and prolong its useful life. To have the greatest sealing effect, the most appropriate skeleton oil seal may be chosen by carefully weighing the shaft’s characteristics, the operating environment, the sealing medium and the economics.
