A hydraulic cylinder converts hydraulic fluid pressure into linear force and motion. When pressurized fluid is introduced into a cylinder chamber, it pushes the piston which transfers force to the piston rod. By directing fluid to either side of the piston (in double-acting cylinders) or to a single chamber (in single-acting cylinders), controlled extension and retraction are achieved.
How it works (step-by-step)
Fluid supply: A hydraulic pump in the powerpack forces oil through directional valves toward the cylinder.
Pressure build-up: Fluid enters the cylinder chamber and builds pressure against the piston face.
Piston movement: The pressure overcomes load resistance and the piston moves, producing linear force on the rod.
Flow control: Flow valves determine the piston speed; pressure valves limit maximum force.
Return stroke: In double-acting cylinders, fluid is routed to the opposite side of the piston to retract it. In single-acting cylinders, a spring or external load returns the piston.
Sealing & leakage control: Rod seals and piston seals maintain pressure and prevent internal/external leakage.
Key features & controls
Directional control valves for stroke direction.
Flow control (speed) and pressure relief (safety).
Check valves for load holding and anti-cavitation.
Accumulators (optional) for damping and emergency retraction.
Typical applications
Construction equipment, truck/wagon tipplers, roller presses, packaging plants, baling and shearing presses — anywhere precise linear motion under load is required.
Why testing matters
Function tests, proof pressure, and internal bypass tests ensure the cylinder meets performance and safety criteria before dispatch.