Heat can be a significant
problem for sealing compo-
nents. One strategy for heat
reduction is using centrifugal
force to reduce drag, which is
the operating strategy behind
Simrit’s CASCO shaft seal,
which incorporates an axial lip
rather than a radial lip to cre-
ate the sealing barrier.
viscosity and lubrication properties
of the fuel, all of which may affect
the elastomers. In parallel, oils are
being formulated for longer life and
improved stability at higher temperature, which can introduce additives
often aggressive to elastomers.
To meet emissions reduction regulations, engine manufacturers must
incorporate advanced sealing components, materials and technologies
into their existing engine designs.
Through material and design innovations, sealing components are evolving to meet the challenge of not only
the direct effect on the escape of particulates into the exhaust stream, but
increasing the efficiency of the engine
to allow equal power using less fuel.
It would not be uncommon for a
radial shaft seal at higher speeds to
add approximately 86°F to the oil temperature in the area located between
the seal and shaft. This is the true
temperature the shaft seal material
and the oil must accommodate. If this
temperature generated by the seal
can be reduced by a certain percentage, it decreases the risk of exposing
the seal material and engine oil to
excessive temperatures.
Reductions in heat generation also
TECHNOLOGY
translate to reductions in torque, which
is directly related to parasitic power
loss. Low friction seals that use unique
sealing mechanisms, low friction
materials and even centrifugal force
have proven to reduce drag by an
average of 70%, thus decreasing the amount of heat added
to the system. If the parasitic
energy losses can be reduced,
the engine becomes more efficient and less fuel is needed to
produce the same amount of
power — and less fuel equals
lower emissions.
As an example, Simrit’s
Springless Energy Saving Seals
Another approach to reduce the
heat generated from sealing components is using centrifugal force to
reduce drag. The main lip of Simrit’s
CASCO design contacts a surface
perpendicular to the shaft, rather than
radially on the shaft itself. This configuration is intended to eliminate the
need for the engine manufacturer to
spend significant amounts of time
preparing the shaft sealing surface. A
number of engine manufacturers are
adopting this design as it incorporates
an axial lip rather than a radial lip to
create the sealing barrier.
VDO - A Trademark of the Continental Corporation
continued on page 100
VDO ALAS I and ALAS II Fuel Senders
Reliability meets
adaptability.
www.vdo.com/usa
With today’s tank configurations, you
need choices more than ever when
it comes to fuel senders. Our new
generation ALAS I and ALAS II offer
just that, plus reliability, accuracy, and
most importantly, flexibility. Both new
senders have redundant dual wiper
systems and ‘quiet arm’ technology,
plus 39-step thick film resistors that
will provide over one million swing
arm cycles. Each sender is designed
for tank depths of up to 400mm and
has slotted flange mounts. These are
the most flexible sender systems in
the industry.
The ALAS I and ALAS II fuel
senders’ robust and versatile design
accommodates a wide range of
applications, from small engines to
agricultural and industrial machinery.
For additional information, contact:
salessupport-us@vdo.com
Instrumentation | Sensors | Fuel Supply
Engine Actuators | Washer Systems
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