VMI Viber X, Руководство пользователя

Страница: 10 / 20

10
Vibration Measurement Instruments
The ISO standard is classifying the machines differently if the
machines are considered as fl exible or rigid mounted. This refl ects
the location of the machines stiff-body resonance’s related to the
basic running speed of the machine.
For instance, a machine supported by rubber or springs have
resonance’s at low running speeds. The machine starts vibrate
at certain low rpm. When the speed is increased above these
resonance frequencies the vibration is reduced. This machine is
considered fl exible.
A resonance can easily be found when a fl exible machine is
running up or down in speed. The resonances are located at
the rpm´s where the vibration has a local maximum level.
Manual Viber X1_121002.indd 10 10/3/12 9:26 AM
The ISO standard classifies the machines differently if the machi -
nes are flexible or rigid. This reflects the location of the machine’s
stiff-body resonance related to the basic running speed of the
machine.
For example, a machine supported by rubber or springs have a
resonance at low running speeds. The machine starts vibrate at
a low RPM. When the speed is increased above these resonance
frequencies, the vibration is reduced. This machine is considered
flexible.
Resonance is easily found when a flexible machine is running up
or down in speed. The resonances are located at the speed where
the vibration has a local maximum level.
Rigid
1.4
mm/s
2.8
4.5
11
Group 2 and 1 Group 4 and 3
Rigid Flex. Flex. mm/s
2.3
3.5
7.1
Extraction’s from ISO 10816-3
Industrial machines with power above 15kW and nominal
speeds between 120 - 15000 RPM.
Group 1:
Large machines with rated power
above 300kW. Electrical machines
with shaft height H > 315mm.
Operating speed ranges from 120 to
15000 RPM.
Group 2:
Medium-sized machines with a rated power above 15kW up to and
including 300kW. Electrical machines with shaft height between
160 < H < 315 mm. Operating speed normally above 600 RPM.