Cylinder Geometry
Bore Diameter D
100 mm
Typical range: 25–320 mm
Rod Diameter d
56 mm
Typically d ≈ 0.5–0.7 × D
Stroke Length L
500 mm
Operating Conditions
Working Pressure p
14.0 MPa
Industrial: 7–21 MPa / High: up to 70 MPa
Flow Rate Q
20.0 L/min
Back Pressure pback
0.5 MPa
Mechanical Efficiency η
95 %
Seal Design
Safety Factor S.F.
2.0 ×
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Extension Force [kN]
—
Retraction Force [kN]
—
Extension Speed [mm/s]
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Retraction Speed [mm/s]
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Hydraulic Power [kW]
—
Seal Rating [MPa]
Pressure vs Force Characteristic
Core Equations
Piston area and annular area:
$$A_{bore} = \frac{\pi D^2}{4}, \quad A_{ann} = \frac{\pi (D^2 - d^2)}{4}$$Forces (with back-pressure and efficiency):
$$F_{ext} = (p \cdot A_{bore} - p_{back} \cdot A_{ann}) \cdot \eta$$ $$F_{ret} = (p \cdot A_{ann} - p_{back} \cdot A_{bore}) \cdot \eta$$Velocity: $v_{ext} = Q / A_{bore}$, $v_{ret} = Q / A_{ann}$
Hydraulic power: $P = p \times Q$
CAE Note: FEM stress analysis of cylinder barrels uses thin-wall hoop stress σ = pD/(2t) as a starting point. For high-pressure cylinders (>35 MPa), Lamé's thick-wall cylinder equations are required. Rod buckling is checked against Euler's critical load with appropriate end conditions.
Force & Speed vs Bore Diameter Matrix
Design Tip: Larger bore increases force but reduces speed at the same flow rate. Increasing the rod-to-bore ratio raises the speed differential; a differential circuit can achieve rapid advance at reduced force (approximately half of normal extension force).