Hydraulic Cylinder
Compute theoretical thrust, piston velocity and output power for double-acting hydraulic cylinders in advance/retract strokes.
Inputs
Formula
F_adv = p·πD²/4; F_ret = p·(πD²/4 − πd²/4); v = Q/A; P = F·v
Fundamentals
A hydraulic cylinder converts fluid power to linear mechanical motion — the actuator of a hydraulic system.
Output force $F=pA$, $p$ pressure, $A$ piston area; the blind end area exceeds the rod end, so extend force exceeds retract.
History
Hydrostatic transmission stems from Pascal (1653); modern cylinders came with 20th-c. hydraulics for machinery.
Engineering applications
Used as linear actuators in excavators, presses, injection moulders and lifts.
Glossary
| Pressure $p$ | Supply pressure (Pa). |
| Piston area $A$ | Effective area, $A=\pi D^2/4$. |
| Push / Pull | Extend vs retract force differ by area. |
How to use
- Fill in Bore dia. D, Rod dia. d, Supply pressure p, Flow Q in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Advance thrust, Retract thrust, Piston velocity, Output power in the results area.
Formula notesCylinder force F = p·A = p·π d²/4; p = system pressure, d = piston diameter.
Formula · Worked Example · Knowledge
Formula
Double-acting cylinder thrust $F_{adv}=p\pi D^2/4$, $F_{ret}=p(\pi D^2/4-\pi d^2/4)$; velocity $v=Q/A$, power $P=Fv$.
Worked Example
D=80, d=40, p=16 MPa, Q=40 L/min → Fadv≈80.4 kN, v≈0.199 m/s, P≈16 kW.
Key Points
- Retract thrust is lower (rod takes area).
- Speed ∝ flow, ∝ 1/area.
- Check barrel strength and rod buckling.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| Bore dia. D (mm) | D | mm | 80 |
| Rod dia. d (mm) | d | mm | 40 |
| Supply pressure p (MPa) | p | MPa | 16 |
| Flow Q (L/min) | Q | L/min | 40 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Advance thrust | Fadv | N |
| Retract thrust | Fret | N |
| Piston velocity | v | m/s |
| Output power | P | kW |
Applications
- Pipe flow rate and pressure drop
- Hydraulic cylinder force/speed design
- Flow-meter selection and calibration
FAQ
What formula does this tool use?
This tool computes per ISO / AGMA / ASME standard formulas: F_adv = p·πD²/4; F_ret = p·(πD²/4 − πd²/4); v = Q/A; P = F·v
How accurate are the results?
Results match input precision, based on SI units and common engineering approximations; for critical duty re-check with a safety factor.
Where is it used?
Pipe flow rate and pressure drop