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Selection For
Equipment Employing Large Ammplitudes :Here
selection involves deciding on type of vibrations
required to carry out process, number of vibrators to be
used and their placement on driven machinery.
a)
Vibration Types:
Could be Circular or elliptical or rectilinear or
torsional. Adjoining Table-3 explains how different
vibrations are obtained by different placement of
vibrators vis-à-vis the machine.
This would
help users decide on number and location/s of vibrator/s
on driven machinery so as to obtain most suitable
vibrators to accomplish a process.

b) Choice of Vibration Frequency,
Amplitude and Acceleration:
These are again decided by the process to be carried
out. The Table-4 bellow shall provide a valuable
guidance for deciding at least a range of these
parameters.
As a thumb
rule; (I) for small and light equipment weighing
15-150 Kgs requiring up to 3 mm amplitude it could be 50
Hz, (ii) for medium sized in 50-500 Kgs weight
range requiring upto 6 mm amplitude it could be 25 Hz
and (iii) relatively large and heavy equipment
weighing 400-4000 Kgs with amplitudes up to 12 mm it
could be 16 Hz. Frequencies could be still lower for
heavier machines having longer strokes.
c)
Vibrator Sizing:
Upon having determined (I) peak to peak amplitude
('A' in mm), (ii) total live & dead mass
including estimated weight of vibro motors/s to be used(
'W' in Kg.s), (iii)vibration frequency/ rpm ('N' per
minute) and (iv)number of vibro motors used to
drive('n').
d)
Vibration isolation Suspension Design
A very important part of vibration machinery and having
great bearing on its efficient working is the
suspension. It should allow free oscillations and
prevent harmful transmission of vibrations to the
surrounding. Generally 95% isolation is satisfactory in
industrial environment and can be obtained by using
resilient mounting having following static deflection
'd' under the weight of vibrating parts.
I) 3000 rpm
synch. speed - 2.5 mm
ii) 1500 rpm synch. speed - 10 mm
III) 1000 rpm synch. speed - 22.5 mm
iv) 750 rpm synch. speed - 40 mm
In the Event
any assistance is required from us, Sinex Primemovers,
in selecting suitable vibro motor/s to drive machinery,
please furnish details of your applications such as
(I) live & dead weight to be vibrated (ii)
amplitude desired, (iii) frequency most suited
for the process, (iv) damping factor present (v) purpose
to be achieved, (vi) material details etc. along
with a drawing / sketch of machine / systems to enable
us work out and submit optimum recommendation. |