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A.0500.501 – IM-TGGS/05.01 EN (03/2013)
3.10 Internals
3.10.1 Bush materials
Overview of bush materials and application field
Material Code
S
C
B
H
U
Material
Steel
Carbon
Bronze
Ceramic
Hard metal
Hydrodynamical
lubrication
if yes
to maximum working pressure = 16 bar
if no
6 bar (*)
10 bar (*)
6 bar (*)
6 bar (*)
10 bar (*)
Corrosive resistance
Fair
Good
Fair
Excellent
Good
Abrasive resistance
Slight
None
None
Good
Good
Dry running allowed
No
Yes
Moderate
No
No
Sensitive to thermal choc
No
No
No
Yes dT<90°C
No
Sensitive to blistering in oil
No
> 180°C
No
No
No
Oil aging
No
No
> 150°C
No
No
Food processing allowed
Yes
No (antimony)
No (lead)
Yes
Yes
(*) These are not absolute figures. Higher or lower values possible in function of the application,
expected lifetime etc.
3.10.2 Maximum temperature of internals
Because the overall temperature of TopGear GS pumps is limited to 200°C, there are no extra
temperature restrictions for internals.
3.10.3 Operation under hydrodynamic lubrication conditions
Hydrodynamic lubrication could be important criteria for bush material selection.
If the bush bearings are running under the condition of hydrodynamic lubrication there is no more
material contact between bush and pin or shaft and the lifetime cycle is increased importantly.
If there is no condition for hydrodynamic lubrication, the bush bearings make material contact with
pin or shaft and the wear of these parts is to be considered.
The condition of hydrodynamic lubrication is fulfilled
with the following equation:
Viscosity * shaft speed / diff.pressure
≥
K.hyd
with:
viscosity [mPa.s]
shaft speed [rpm]
diff.pressure [bar]
K.hyd = design constant for each pump size.
TG GS pump size
K.hyd
2-25
6000
3-32
7500
6-40
5500
15-50
6250
23-65
4000
58-80
3750
86-100
3600
185-125
2500