Grease Relubrication
of FAG Spindle Bearings
Longer grease operating life for peak speeds
Longer grease operating life for peak speeds
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Grease relubrication of FAG spindle bearings
Minimal friction
This has been confirmed in the
Grease lubrication provides the bearing
interdisciplinary research project
with a quantity of lubricant that is at
EnergieMSP, Figure 2.
a minimum but sufficient for operation.
This results in very low friction and
Notwithstanding the benefit of bearings
high energy efficiency, Figure 3.
with pneumatic oil lubrication,
Since the bearings can be operated
the increase in lifetime of grease
reliably and without maintenance,
lubricated bearings is imposing itself
grease lubrication is the type
through the perspectives of
of maintenance most frequently used
sustainability and cost-efficiency. This is
for spindle bearings.
accommodated by Schaeffler through
Figure 1: HCRS spindle bearing,
sealed and greased “for life”
the development and implementation
spindle bearings has proved effective.
not sufficient in many cases.
In order that the advantages of grease
Through the selection of the correct
lubrication can be used even at high
materials and an internal construction
speeds, permanent relubrication must
with optimised friction (series RS),
be provided.
speeds that currently can only be
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loads, the grease operating life is
r with
we
y
po fficienc
e
EnergieMSP
ts
achieved using pneumatic oil
Advantages of grease lubrication
Op
lig timi
conhtw s
st
gh
throu
ion
at ght ion
ei uct
r
For high speeds, oil lubrication of
of suitable relubrication concepts.
Supply of d
high ene rive
rg
y
For a combination of high speeds and
Sp
en
w i i n d l e co m p o n e s
th
s
m i n i m is e d l o s
lubrication are now also possible with
#&53&6570.
In comparison with pneumatic oil
grease lubrication.
15,"
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lubrication, grease lubrication of
Figure 2: Project partner EnergieMSP
spindle bearings has many advantages:
30
compressed air equipment
■ economical lubrication
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■ no requirement for oil or
Ncm
Pneumatic oil lubrication
Grease lubrication, SPEED 2,6
25
■ conservation of resources
■ clean and reliable
■ absolutely maintenance-free
■ sealed versions already filled
“for life” with the correct amount
of the correct grease, Figure 1.
Frictional torque
■ simplified design
20
15
10
1,3
1,4
1,5
1,6
1,7
Speed parameter n dm
Figure 3: Spindle bearings with grease lubrication have lower friction,
as shown in the example of HCB (25°)
106 mm min–1
1,9
Reduction in friction and
increase in the grease operating life
period. One possibility for achieving
increase in grease operating life
of the grease lubricated bearing,
this, apart from cost-intensive
Figure 4.
pneumatic oil lubrication, lies in the use
The grease operating life can be
■ The combination of rolling elements
increased by a range of measures:
■ One option is the use of sealed
bearings. Due to sealing, the grease
remains at the rolling contact,
which means that almost all the oil
present in the grease can contribute
to lubrication. This means
made from ceramic with rings made
With the relubrication devices from
from the high performance steel
Industrial Aftermarket, Schaeffler has
Cronidur®, for example in the
for a long time offered grease
FAG X-life ultra bearings, leads to
relubrication devices for a wide variety
a further increase in the grease
of applications. The new device
operating life.
ARCALUB-X, Figure 5, is highly suitable
for the relubrication of high precision
■ The grease operating life can be
a significantly longer grease
operating life in comparison with
increased further by the use
open bearings.
of high performance bearings
bearings running at high speeds.
The unit is easily mounted in the vicinity
of the spindle and integrated in
of the series RS. Since the internal
■ As an alternative, higher
the machine controller.
construction has optimised friction
specification materials can be used.
The smallest dispensing quantity is
characteristics, this gives lower
The use of balls made from ceramic
0,025 cm3/stroke. The grease reservoir
operating temperatures.
instead of steel in hybrid bearings
of suitable grease relubrication.
carrier can be easily replaced.
The grease is handled in a highly sparing
material pair at the rolling contact.
for main spindle bearings
manner and is only under pressure
As a result, the operating
If a spindle is run continuously at very
during the relubrication process.
temperature is reduced. Less base oil
high speeds, lubricant must be regularly
This principle allows the use of high
is consumed and there is a drastic
added to the bearing in order to ensure
speed greases and ensures optimum
adequate lubrication reliably over a long
grease performance.
50 000
h
30 000
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gives a tribologically superior
Grease relubrication
4
3
20 000
2
10 000
1
F10 5 000
3 000
2 000
100 000
150 000
300 000
200 000
kf n dM
700 000
1 500 000
1 000 000
1 800 000
500 000
min–1 · mm
Figure 4: Grease operating life F10, as a function of the bearing-specific speed parameter kf · n · dm
� steel/steel, � steel/ceramic, � Cronidur®/ceramic, � grease relubrication using ARCALUB-X
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1 000
70 000
Figure 5: Relubrication device FAG ARCALUB-X
MATNR 084093536-0000 / SSD 33 / GB-D / 2014011 / Printed in Germany by mandelkow
Your contact
Dipl.-Ing. Gabriele Laugisch
Telephone +49 9721 91-1975
[email protected]
Schaeffler Technologies
GmbH & Co. KG
Georg-Schäfer-Straße 30
97421 Schweinfurt (Germany)
www.schaeffler.com