Dear Sir,
I am a Professor of machine dynamics at the Alexandria University, Faculty of
Engineering.
We have a VAST DC11 data collector and balancing software. I had a problem in
the dynamic balancing (2 - planes) . May be I can do balancing by the influence
coefficient. I cannot do balancing by other method of trial mass for 2 - plane.
How can I do this balancing by this system . Please send me a step by step
procedure for this process. Thank you in advance.
The question is answered by
Alexander Shablinsky:
Dear Sir,
If we have understood you correctly you do not know how to make balancing for
two or three planes by VAST DC-11 data collector.
If you do not have the User's Guide for the balancing
program, please inform us and we shall send it to you.
Each screen has a detailed HELP (key "?" on the DC-11 keypad).
If you are disturbed that there is no need to define during configuration
the number of planes, don't be confused. In fact before you get the data
about a certain machine you cannot know this number. Our experience shows
that to reduce the vibration to the required level it is often enough to fix
the balancing weight in one plane. If it is not so, after conducting the
measurements of initial vibration, fixing the first trial weight, measuring
the vibration with this weight, calculating the balancing weight for a first
plane choose for your next step the command "Next Trial Weight". The program
will ask the parameters of the trial weight to be placed at the second
plane. If you have the third plane, repeat the procedure. After taking the
vibration measurements the balancing weights for the two or three planes
will be calculated. After fixing them and conducting the "Test Measurement"
the correcting weights will be calculated. The process can be repeated up to
four times. The completion of balancing can be made by the command "Finish".
The selection of possible commands appear on the screen sequentially after
obtaining the information that enables to make this selection.
The balancing by the influence coefficients cannot be made without at least
one balancing with trial weights.
In the first and third cases the standards of unfalty and faulty units are
automatically constructed by a group of machines of similar type, and in the
third case the possibility of machine dangerous condition appearance is
additionally taken into account when the main methods of detailed diagnostics
may already not work and give incorrect results.
In the second case the standard of unfalty machine (unit) is automatically
constructed on the results of preceding intermittent vibration measurements and
the symptoms and defect levels are defined a priori by the results of special
diagnostic investigations with the possibility of these levels following
corrections. In this case it is possible to achieve the most reliable results.
Its own peculiarities has the transport machine and unit diagnostics. For this
type of diagnostics are produced even special diagnostic systems which are often
called the stand systems. They have two peculiarities. The first one is the
result of limitations on the transport mode of operation during the procedure of
diagnostics. It is made not during the transport movement it means not when the
transport has the specified optimal revolution rate and loads applied to the
diagnosed units. The second peculiarity is in often absence of the data
concerning the vibration and noise that could be obtained during periodical
measurements. Consequently the diagnostics is usually made according to the
rules concerning the flaw detection of the equipment that came for repair, viz.
according to the rules for the third group of diagnosed equipment.
