What is a Hydraulic Cylinder? Types, Uses and Care Tips

What is a Hydraulic Cylinder? Types, Uses and Care Tips

What is a Hydraulic Cylinder? Types, Uses and Care Tips

What is a Hydraulic Cylinder?

Hydraulic cylinder is a machine element that converts pressurized hydraulic oil into linear motion in hydraulic systems  . In other words, it converts hydraulic energy into mechanical force. Its most basic function is to increase a force or provide controlled rectilinear motion.

Hydraulic cylinders  serve as an indispensable actuator in industrial applications that require high forces, construction equipment and heavy lifting systems.

Working Principle of Hydraulic Cylinder

The principle of operation of the hydraulic cylinder is  based on Pascal's Law. According to this law, the pressure exerted on the liquid  is transmitted equally and without loss to every point of the liquid.

Operation steps:

1. The hydraulic pump sends the hydraulic oil from the oil tank to the cylinder under pressure.
2. The oil acts on  the piston surface inside the cylinder,  creating force.
3. This force moves the piston rod forward or backward.
4. Movement is used as mechanical work (load lifting, pressing, compressing, etc.).

In this way, a small oil pressure  can be converted into very high forces.

Basic Components of Hydraulic Cylinder

• Cylinder Body: The main part where the hydraulic oil moves under pressure, the piston slips.
• Piston and Piston Rod: The part that converts the force of the pressurized oil directly into mechanical motion.
• Gasket and Sealing Elements: Prevents oil leaks, maintains pressure.
• Caps (Front & Rear): The parts where the oil enters and exits, directing the piston rod.
• Fasteners: Allows the cylinder to be fixed to the machine (joint, flange, clamp).

Advantages of Hydraulic Cylinder

High force generation capacity
Linear and controlled movement
Durability and longevity
Large power transmission in a compact design
Easy integration into automation systems

Types of Hydraulic Cylinders

1. Single Acting Hydraulic Cylinder

• It moves in one direction with oil pressure.
• Return is provided by the action of spring or load.
• It has the advantage of simple design and low cost.

2. Double Acting Hydraulic Cylinder

• Both forward and backward movement takes place with oil pressure.
• It is preferred in applications where high force and precision are required.

3. Telescopic Hydraulic Cylinder

• It consists of multiple stages, provides a long stroke length.
• It is used in dump trucks, cranes and lifting systems.

4. Rotary Hydraulic Cylinder

• It produces rotational motion instead of rectilinear motion.
• It is used in special machines.

Hydraulic Cylinder Usage Areas

Hydraulic cylinders provide linear motion by converting pressurized hydraulic oil  into high force  . Thanks to their durability, powerful performance and precise control possibilities, they are used in many industries.

 Let's examine in detail the usage areas of hydraulic cylinders according to the sectors below:

1. Construction & Construction Machinery

Most of the machines used in the construction industry perform their lifting and moving functions thanks to hydraulic cylinders.

• Excavators: Bucket and boom movements
• Buckets: Excavation and loading operations
• Forklifts: Lifting palletized loads
• Cranes: Weight lifting and turning mechanisms
• Dump trucks: lifting the crates up

Here, hydraulic cylinders  offer a combination of high force + durability.

2. Industry & Production Lines

Production machines used in industry require high precision and reliability.

• Hydraulic presses: Metal forming, forging, mold work
• Plastic injection molding machines: Opening and closing of molds
• Assembly lines: Automated motion systems
• Cutting and bending machines: Sheet metal processing applications

Hydraulic cylinders  provide fast, repeatable and controlled movements here.

3. Agricultural Machinery

Agricultural machinery operates in harsh conditions and requires reliable equipment.

• Tractor attachments: Tillage, hoisting
• Balers: Compression and packaging
• Harvesters: Cutting and picking systems
• Sprayers: Opening and closing of arms and levers

In agriculture, hydraulic cylinders  provide operational efficiency and labor savings.

4. Transportation and Logistics

Hydraulic cylinders take an active role in the transportation, loading and unloading of cargo in logistics.

• Truck tippers: Unloading
• Trailer systems: Hydraulic swing doors
• Bus and train doors: Controlled opening and closing
• Container lifting systems

Safety and durability are the priority here.

5. Energy and Infrastructure Sector

Large-scale hydraulic cylinders are used in power generation and infrastructure projects.

• Hydroelectric power plants: Opening and closing of dam gates
• Wind turbines: Blade angle control
• Oil and gas installations: Valve control mechanisms
• Bridge and tunnel systems: Opening bridges, locking systems

In this area, cylinders are  critical for heavy-duty and safety-oriented applications.

6. Special Applications

• Defense industry: Tank covers, weapon systems
• Marine: Ship covers, cranes
• Mining: Crushing machines, lifting systems
• Automotive: Lifting lifts, testing machines

Hydraulic cylinders are indispensable in modern  industry as they provide high strength, precision, and reliability in different industries  . Regardless of the area of use, a properly selected and regularly maintained hydraulic cylinder extends the life of the system and increases operating efficiency.

As Hidroman, we offer customized hydraulic cylinder solutions for the construction, industry, agriculture and energy sectors. For more information, you can visit hidroman.com.tr.

Common Hydraulic Cylinder Failures

Malfunction	Symptom	Reason	Solution
Oil Leakage	Oil around the cylinder	Worn gasket, damaged surface	Gasket change, surface grinding
Power Loss	Inability to lift loads	Internal leakage, piston wear	Gasket set replacement, piston refurbishment
Scratches and Wear	Damage to the cylinder body	External impacts, improper assembly	Grinding or body change
Unstable Movement	Titreşim, yalpalama	Tilted piston rod, improper bearing	Piston rod straightening or replacement

 

Hydraulic Cylinder Maintenance Tips (Detailed Guide)

1) Don't Start Without Safety and Cleanliness

• Lock-out/Tag-out: Leave the system without pressure and energy, mechanically secure the moving loads.
• Clean operation: Have port caps, clean cloth, stopper, and oil-absorbent pad. Dust/metal particles are the worst enemy.
• The right tool: Torque wrench, measuring caliper/micrometer, flat surface ruler, pressure gauge, temperature probe, flow meter/leak test rig.

2) Daily–Weekly Checks (Quick look at the field)

• Visual leak control: Rod wiper, rod seal and port surrounds.
• Rod surface: Scratches, chrome peeling, rust; The feeling of "nailing in" is a bad sign.
• Motion quality: Note if there is a stick-slip, vibration, abnormal sound.
• Temperature: If the cylinder body/oil temperature rises significantly above normal (according to the system), investigate the root cause.
• Connections and assemblies: Are pins, bushings, nuts loose? Is there a lateral load trace?

3) Monthly Checks (Condition monitoring)

• Cushions and limits at the end of the stroke: Are there any signs of impact, impact marks, going out of the stroke?
• Alignment and lateral load: Uniform wear on joints and flanges; increased clearance in bushings. If necessary,  use a self-aligning joint.
• Filter/oil cleaning: The health of the system as a whole determines the life of the cylinder. Monitor filter indicators, by-pass warnings.
• Pressure settings: Make  sure that the safety valves do not create "redundant" overpressure.

4) Oil and Sealing Discipline

• Cleaning class: Dirty oil; quickly wears out rods, bearings and seals. Have an oil analysis (particle, water) done.
• Proper oil/seal compatibility: Make sure materials such as NBR/FKM/PU etc. are compatible with the oil and temperature.
• Wiper health: Wipers are the main defense in dusty/muddy environment; replace without delay in deformation.
• Port closure and ventilation: Be sure to close the ports during storage/transportation, thin oil film on the rod side.

5) Typical Symptom → Possible Cause → First Response

• Oil ring/drip on rod ends → Rod seal is worn, rod is scratched, pressure is fluctuating.
  First response: Remove pressure surge, check rod surface; replace seals if necessary.
• Drift (slow sag under load) → Internal leakage (piston seal/valve).
  First responder: Leak test (see procedure below); seals/piston set replacement if leakage is high.
• Stick-slip → Side load, rod/guide wear, faulty oil viscosity, contamination.
  First intervention: Alignment, bushing/pin checking; oil cleaning/viscosity verification.
• Point rust/pothole in rod → Wiper weak, washing insufficient, corrosive environment.
  First intervention: Protective coating/bellows, rod cleaning-lubrication after operation, wiper replacement.

6) Cylinder Leakage/Drift Test Procedure (Workshop)

1. Connect the cylinder to the test stand; Perform air purge operation.
2.  Position the cylinder close to the nominal pressure in the thrust direction.
3. Close the ports and  perform  a 10-15 minute dwell with a pressure gauge and ruler.
4. Record the pressure drop and piston position change.
5. Repeat for the direction of  pulling.
6. Confirm external leaks with fluorescent dyed oil and UV lamp (if applicable).

Note: The acceptance criterion should be determined by the OEM; the important thing is repeatable measurement and trend tracking.

7) Mounting and Alignment Tips

• No dry assembly: Soak the felt and bearings with clean oil.
• Concentricity: Check the knuckle/flange alignment with the alignment gauge; minimize side load.
• Flex:  Leave one end articulated for thermal expansion on a long stroke.
• Torque values: According to the manufacturer's chart; excessive torque  can cause tube ovalization.
• Hose routing: Minimum bend radius, no torsion; release parallel to the stroke.

8) Environmental Protection

• Dust/mud: Rod protection bellows, scraper/wiper dual design, frequent washing.
• Marine/corrosive: Stainless/hard chrome alternatives, coating and regular anti-rust film.
• Temperature: High temperature viscosity management and sealing material revision.

9) Warehouse and Transportation

• Store the rod in the fully retracted position.
• The ports are closed, the rod surface is protected by a thin oil film.
• Do not store vertically (for a long time); horizontal and supported, refresh the film once a month by moving the rod slightly.
• Case/packaging: Protect from impact and moisture.

10) Recommended Maintenance Plan (Sample table)

Period	Work To Be Done	Purpose
Daily/Weekly	Eye leakage, rod surface, sound/vibration control	Early warning
Monthly	Visual inspection of alignment, pin/bushing clearance, wiper and rod seal	Reducing side load and contamination
3–6 Months	Leak/drift test, end-of-stroke buffer check, linkage torque verification	Capture internal leakage and impact damage
Annual	Oil analysis report, seal set status, rod coating inspection	Lifecycle planning
Revision	Seal set/piston guides replacement, rod grinding/reconditioning (if required)	Full performance recovery

11) Actionable Checklist (abbreviated)

• Is the system pressure/temperature controlled within the normal range?
• Are there any external leaks?
• Are there any scratches/rust on the rod surface?
• Are the wipers and seals intact?
• Are there traces of side load, are the joints hollowed out?
• Is there a blow at the end of the stroke?
• Is the leak/drift test recorded?
• Is the oil cleaning/filter condition appropriate?

Hidroman stands by businesses with hydraulic cylinder solutions and maintenance services suitable for different sectors  ! For more information, visit hidroman.com.tr.