Lip
seals are used to seal rotary elements, such as a shaft or rotating
bore. The seal construction will consist of a sprung main sealing lip
which has a point contact with the shaft. The point contact is formed
by two angles, with the air side angle usually less than the oil side
angle. Depending on the seal type these two angles are varied to
create a pressure
distribution at
the seal contact point which has a steeper slope on the oil side of
the seal. The shallower the slope on the oil side of the seal the
wetter the seal will run. The spring is positioned such that axially
the centerline of the spring is biased to the air side of the lip
contact point.
A
lip seal is a rotary seal incorporating a deflected lip seal
geometry. Anti rotational devices such as flanges and O rings are
often utilized to prevent the seal from rotating with the shaft.
Standard and custom sizes are available with a wide selection of PTFE
or Polytetrafluoroethylene
materials. A lip seal is suitable for sealing
corrosive and abrasive media. A wide range of geometries and
materials are available in the market, depending on specific
requirements of the applications. Lip seals are often used on motors
and compressors and other components with high speed rotary shafts
due to their ability to resist wear even while pressurized.
The
most common lip shape is the chamfered or back beveled design and is
available with the V and C Series spring types. This design allows
for ease of installation and permits lubrication to nest under the
lip and feed through in reciprocating dynamic applications. The
result is a microscopic film of lubrication that increases seal and
hardware service life. Since the footprint (contact point) of a
chamfered lip is a single point, all of the sealing force is
concentrated on that point, yielding the highest sustainability and
lowest friction.
Applications
often involve media with abrasive particles that can get caught
between the seal lip and the mating hardware. This increases wear to
both the seal and the mating surface. To prevent particles from
accumulating, the scraper lip design is available with all three
spring types. The scraper lip contact point is positioned directly
over the load point of the spring in each design for maximum scraping
action. The scraper lip can be positioned on the ID, OD or both. The
scraper lip also stays in place better in a stepped gland where the
step is not very large.
The
beaded shape contacts the surface in much the same way as an O ring,
and is available with the V and H Series spring types. Similar to the
chamfered lip, it is easy to install and helps to lubricate the
reciprocating sealing surface. In fact, the beaded lip yields a film
of oil that is slightly thicker than that of a chamfered lip, making
it advantageous for applications with rapid reciprocating motion.
Darcoid Nor Cal Seal is an excellent supplier of lip seals. Darcoid
Nor Cal Seals caters to all kinds of sealing solutions Access Door
Seals, Dynamic metal seals, rubber sealing rings, Fastener and
Fitting Seals, Gask O Seals, Integral Seals, Lock O Seals, Metal
Seals, O Seals, Pipe Flange Gask O Seal, Stat O Seals, O rings,
Thredseal, vacuum face seals, different kinds of gaskets and the
likes. The company supplies a large number of seals, rings, gaskets
and scrapers or wipers specifically engineered for various
applications in a myriad of industrial sectors.
Lip
seals
operate in various different applications in many industries
including aerospace, pharma, defence and more.
