Found on many industrial and agricultural machines, the hydraulic cylinder is an actuator which allows to create a mechanical movement and exert significant pushing or pulling efforts.
The force produced can then be linear or angular.
What is a hydraulic cylinder made of ?
Hydraulic cylinders are made up of a cylindrical body in which a rod and a piston are located, allowing the volume of the cylinder to be separated into two sealed and isolated chambers.
The introduction of a pressurized fluid into the orifice of one of these chambers, through a hydraulic distributor, then causes a thrust on the piston and gives the rod an in or out movement.
The hydraulic cylinder converts hydraulic energy (hydropower) into mechanical energy. Pressurized oil is the most commonly used fluid.
The hydraulic actuator allows a precise adjustment of the rod’s movement speed, as well as important forces.
The characteristics of the cylinder are defined by its stroke, by the diameter of its piston, as well as by the pressure that it can admit :
- The stroke corresponds to the distance which the cylinder can travel, from fully closed to fully opened.
- The generated force depends on the pressure of the fluid and the diameter of the piston.
The hydraulic cylinder output force can be determined using the following formula : F (cylinder force in lbs) = P (pressure applied in psi) x A (surface area).
What are the different types of hydraulic cylinders ?
Depending on the nature of the movement to be carried out, different types of hydraulic cylinders exist.
Single-acting and double-acting cylinders are differentiated by the number of orifices allowing the entry of oil.
The single-acting hydraulic cylinder only works in one direction, with its return being carried out under the action of a spring or an external load.
The double-acting hydraulic cylinder has two orifices and thus allows two distinct movements to be created, depending on which port is supplied with pressurized oil.
The telescopic cylinder (with 2 expansions for example) is equipped with several interlocking rods, allowing long strokes in small spaces.
The servo actuator is a servo-controlled hydraulic cylinder, which can be equipped with a proportional control valve or a servo valve, and with one or several sensors. Depending on its performance, it will also be equipped with low-friction seals or hydrodynamic bearings. The most efficient servo cylinders will be equipped with hydrostatic bearings.
Rotary actuators, unlike linear actuators, convert hydraulic energy (hydropower) into rotation to create torque.
The gas spring, sometimes referred to as gas strut or gas shock, consists of a precision rod attached to a piston, moving within a sealed cylinder containing pressurized gas. Gas springs are very often used in stamping applications as a replacement for wire springs.
Quiri, expert in the design and manufacture of hydraulic systems, machinery & hydraulic actuators
As a specialist in the design and manufacture of hydraulic systems, machinery and hydraulic actuators (industrial hydraulics), Quiri offers a wide range of cylinders (locking cylinders, clamping cylinders, double and single-acting cylinders…) meeting the most demanding requirements in terms of durability and performance. Please do not hesitate to contact our experts for any questions about our industrial hydraulic cylinders.
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