Hello sir,
I am Dinesh from Servocontrols.
Recently, I came across one natural frequency formula from rexroth trainers guide
Which differs slightly from the formula that Peter has mentioned in many hydraulic articles.
I just want to know, why is that difference?
It is a bit difficult to tell what the Rexroth formula is exactly without seeing their definitions. I believe the two formulas are the same, just with the Rexroth version using some slightly different terminology.
They use Eoil which I presume is a measure of the stored energy in the oil, and then substitute H/2 x AR to denote the volume. I take this to mean some kind of rod area by perhaps a height? It is not clear from context. In any case, it appears to arrive at the same expression, just with slightly different symbols for the various terms.
I recommend this thread, Computing the Natural Frequency of the Cylinder and Load, to see a worked out example.