F
Rotor balancing
F:19
ISO balancing standard 1940-1
Determination of permissible residual unbalance
The recommendations are given based on experi-
ence concerning the balance quality requirements
of rigid rotors, according to type, mass and
service speed.
There are three methods used to determine the
permissible residual unbalance (U
per
):
•
Empirical quality grades derived from long
term practical experience from a large number
of rigid rotors
•
One experimental method often used in mass
production balancing
•
Method based on specific permissible bearing
forces, calculated by defining U
per
as a sum
of the permissible residual unbalances in the
bearing planes.
The result from the measurements (mm/s) will be
recalculated into values that can be compared
to the graph described in ISO 1940-1.
The balancing result for single plane, 2 runs and
the result after applying the balancing weight
and the trim weight will be plotted into a graph
for the selected balance quality grade (G1, G2.5,
G6.3 or G16) (1).
The residual unbalance is depending on the actual
rotational weight, the distance of the balancing
weight from the centre of rotation and the speed
of the application.
The result is described as a value that is independ-
ent of speed and the rotational weight U
per
/ gr.mm.
In the example, the residual unbalance is 321 gr/
mm compared with the limit 700 gr/mm valid at
150 kg, rotating at 2000 rpm and the position of
the weight at 500 mm from centre of rotation.
The limit is depending on the weight of the
rotational mass and the RPM.
The residual unbalance value is depending on
the position from the centre of rotation of the
balancing weight.
For more detailed information, please see ISO
standard 1940-1.
1
Summary of Contents for leonova emerald
Page 1: ...User guide PORTABLE EFFICIENCY ...
Page 2: ......
Page 6: ...A 2 General instrument functions A ...
Page 36: ...B 2 General measurement functions B ...
Page 74: ...C 2 Measurement techniques always included B C ...
Page 88: ...D D 2 Shock pulse measurement ...
Page 122: ...D D 36 Shock pulse measurement ...
Page 124: ...E E 2 Vibration measurement ...
Page 150: ...E E 28 Vibration measurement ...
Page 152: ...F F 2 Rotor balancing ...
Page 170: ...F F 20 Rotor balancing ...