Hydraulic cylinder§3

Sizing and pressure

Section 3

Hydraulic cylinder sizing

The cylinder replaces the spring. With a 0.6 m lever arm between pivot and attachment point: force ≈ 4,238 N (432 kgf).

Pascal's Principle

F = P × A

F: force (N) — P: pressure (Pa) — A: piston area (m²). Diameter follows from d = √(4A/π).

Recommendation

Double-acting hydraulic cylinder, 140 bar, 20–25 mm bore, stroke adapted to desired angle — standard in agricultural/construction industry, easy to source.

Gas spring alternative: 2–3 gas struts at 4,000 N mounted in parallel — less precise, no intermediate locking.

PressurePiston ØRemark
70 bar28 mmLow pressure, wider cylinder
140 bar20 mmRecommended — agricultural/construction standard
210 bar16 mmHigh pressure, more compact cylinder

Interactive cylinder calculator

Required force

2 543 N·m
0 N·m6 000 N·m
0,60 m
0,2 m1,5 m
140 bar
40 bar250 bar

Required force

4 238 N

432 kgf

Required piston Ø @ 140 bar

19,6 mm

F = P × A

Piston diameter by pressure (F = 4 238 N)

Plus la pression est élevée, plus le vérin est compact. Recommandation : vérin double effet 140 bar, Ø 20–25 mm — standard agricole/BTP.

Animation — cylinder in action

Hydraulic cylinder in action

The double-acting cylinder pushes the piston rod against an arm attached to the cradle. Extending the rod rotates the barrel around the trunnion.