Whisper Slide
If you do not comply with the
2:1 Ratio, you will
notice binding, sticking and ratcheting. If your
pillow block spacing is less than 1, then you
must increase the distance between the
pillow blocks.
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Whisper Slides are
an economical selection and possess some
meaningful - all around - advantages:
All Weather Operation
Washdown Rated
No Mechanical Components that can Catastrophically Fail
Lightweight Construction
High Load Capability
Smooth Running
Quiet Operation
Excellent In Contaminated Environments - Dust, Debris
That's the upside. Now the downside.
Sleeve bearing systems, like our Whisper Linear Slide, have
an inherent drawback called "stiction."
Because sleeve-bearings have a lot of contact area ( as
opposed to a point loaded ball or roller ),
they require a greater amount of force - than a ball or
roller - to get under way. We use a .3 multiplier
when we size these slides. EXAMPLE: If you had a 100
pound load applied uniformly over the
4 bearings of the carriage block, in a horizontal
orientation, it would take 30 pounds of force to get
the slide moving. Once the slide transitions from static to
dynamic, the frictional characteristics
become uniform and the force required drops dramatically.
Edge Loading: Edge Loading can be an issue with
sleeve-type linear bearings and systems.
If there is a moment load applied to these slides we have to
employ what is commonly called the
2:1 ratio between the length of the moment arm and the
distance between shafts ( horizontal orientation )and
distance between bearings on one shaft ( vertical
orientation ).
EXAMPLE VERTICAL: If I have a vertical lift system
and I have a 90° moment arm of 10" carrying
aload of 40 pounds then the distance between the bearings on
shaft must be a minimum of
5" apart inside to inside. Because Whisper Linear Slides
feature a carriage plate that employs
an aluminum extrusion top plate, we can make a longer plate
to accommodate the required
bearings spread. To be honest, I would like to see a 1:1
ratio on these vertical applications.
Max Linear Velocity:
150 Surface feet Per Minute with Load
Requires no Lubrication/Maintenance
Free
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Speed Demon
Roller Blocks
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SPEED DEMON SG/OSG/EL300 Linear
Roller Blocks If
friction, sticktion or edge loading is an issue, then you
might want to consider our Speed
Demonlinear roller blocks. These slides offer lightweight
aluminum extrusion construction with hardened steel shafting
and rollers. These linear roller blocks have good load
capabilities, can accommodate moderate moment loading
while providing very low friction.
Max Linear Velocity:
10 meters per second.
Requires no Lubrication - Bearings are sealed and Lubed
for Life/Maintenance
Free
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Profile Rail Guides
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Profile Rail Systems
For low friction,
high loads and extreme moment loading, profile rail guides
are the
best answer. These bearings are capable of taking up to
65,000 pounds of load
per bearing ( Size 65 ) while ensuring high stiffness, high
accuracy and
extremely low friction.
Max Linear Velocity: 3
meters per second
Requires Lubrication |