In a servohydraulic system, a cylinder extends faster than it retracts. This may seem counterintuitive, especially since it is true in a flow-limited system, which is what many hydraulic specialists are familiar with.
Videos:
-
Intuitive Explanation (3 min):
Explains intuitively why a cylinder extends faster than it retracts, considering pressures, flow, and forces:
Why a Hydraulic Cylinder Extends Faster than it Retracts -
Mathematical Derivation (11 min):
Mathematical derivation of the formulas of the cylinder velocity in both directions, proving why it extends faster than it retracts:
The Math Behind Why a Cylinder Extends Faster than it Retracts
Document:
The attached document provides an explanation of why this is, with a mathematical explanation of the pressures, flow, and forces, yielding formulas for the cylinder velocity in both extending and retracting directions. It also presents how much faster the cylinder will extend than retract.