Vibration
Vibration
(OP)
Can one of you kind gents help me out here. We have specification from a client stating "" that the vibration of the motor shall not exceed 0.5 mil double amplitude in any direction at full or no load "". The motor in question is a IEC 400 frame with sleeve bearings. The motor spec states vibration according to IEC60034-14.and is expressed in vibration velocity as 2.3mm/s rms. So how do you convert 2.3mm/s to mil double amplitude value.





RE: Vibration
RE: Vibration
RE: Vibration
Where A is double amplitude, v is velocity and w is angular speed in rad/second.
Since cos(wt) cannot be more than 1, you get:
v = A/2*w
so, v = A/2*6.28*RPM/60
This is true for SI units, but if you express amplitude and speed in mils and mils/s, you can use it without any further unit conversions.
Convert mm/s to mils/s:
2.3 mm/s = 2.3*1000/25.4 = 91 mils/s
Which results in
v = A/2*6.28*RPM/60
or, in your case:
2.3*91 = A/2*6.28*RPM/60
A= 2*60*2.3*91/(6.28*RPM)
If your machine does 1500 PRM, you get
A = 2.7 mils double amplitude
And, at 3600 RPM, 1.1 mils double amplitude.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Vibration
As your machine is 1500 RPM, the double amplitude is 3.8 mils.
Either I am wrong - or the spec calls for a specially balanced machine.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...