Cap-end volume
Volume required for extension.
Fluid mechanics · Hydraulics
Hydraulic cylinder oil volume and stroke time
Displaced volume equals active area multiplied by stroke. Theoretical time is then volume divided by flow rate.
Created v1.0
By Thibaut Grzelak, Mechanical Analysis Engineer
02
Results
Rod-end volume
Volume required for retraction.
Extension time
Theoretical extension duration.
Retraction time
Theoretical retraction duration.
Relation and numerical substitution
V = A · L ; t = V / Q—
Constant flow rate. Full stroke travelled. Incompressible fluid. Leakage, acceleration ramps and cushioning ignored. d < D.
01Formulas and symbols
Formulas used
Vsortie
Ap·LCap-end volumeVrentrée
Aa·LRod-end volumet
V/QStroke time02Assumptions and limits
Scope of validity
- Constant flow rate.
- Full stroke travelled.
- Incompressible fluid.
- Leakage, acceleration ramps and cushioning ignored.
- d < D.
03Validation example
Reference numerical case
- Q = 20 L/min, D = 50 mm, d = 25 mm and L = 500 mm.
- Vextension = 0.98175 L; Vretraction = 0.73631 L; textension = 2.945 s; tretraction = 2.209 s.
04References
Technical references
- Cylinder volume V = A·L.
- Volumetric flow Q = V/t.
Hydraulic preliminary sizing
Size a hydraulic cylinder: force, bore, flow and speed
Pressure and force determine required area. Area sets bore, then flow determines speed and stroke time.
Cap-end bore
Minimum bore depends on required force, available pressure and efficiency.
D = √[4F / (πPη)]Rod-end area
During retraction, the rod reduces active area.
Aa = π(D² − d²) / 4Complete calculation
The dedicated calculator connects force, bore, rod, stroke, time and flow.