Brief introduction to hydraulic cylinders

Hydraulic cylinders are hydraulic actuators that convert hydraulic energy into mechanical energy and perform linear reciprocating motion (or swinging motion). They have a simple structure and reliable operation. When using it to achieve reciprocating motion, the deceleration device can be eliminated, and there is no transmission gap, and the movement is smooth, so it is widely used in the hydraulic systems of various machines. Below, the Jianlong Hydraulic Technology Team briefly introduces the relevant structure and working principle of hydraulic cylinders:

1. Basic structure

Hydraulic cylinders are mainly composed of the following components:

1.1 Cylinder barrel: a closed cylinder that contains hydraulic oil and pistons and needs to withstand high pressure.

1.2 Piston: divides the inside of the cylinder barrel into two chambers (rod chamber and rodless chamber), which move under the action of pressure oil.

1.3 Piston rod: connects the piston to the external load and transmits thrust or tension.

1.4 Seals: prevent hydraulic oil leakage (such as piston seals, rod seals).

1.5 End caps: close both ends of the cylinder barrel, usually with buffer or guide structures.

2. Working Principle

After the hydraulic oil is pressurized by the hydraulic pump, it enters a chamber of the cylinder through the control valve, pushes the piston to move, and the oil in the other chamber returns to the oil tank. By adjusting the flow direction and pressure of the oil, reciprocating linear motion can be achieved.

3. Main types

3.1 Single-acting hydraulic cylinder: only one side is supplied with oil, and it is reset by external force (such as spring or gravity) (such as dump truck lifting cylinder).

3.2 Double-acting hydraulic cylinder: oil is supplied alternately on both sides, and bidirectional output force (commonly seen in excavator arms).

3.3 Multi-stage cylinder (telescopic cylinder): nested design, long stroke but short retracted length (such as crane arms).

3.4 Swing hydraulic cylinder: output rotary motion (limited angle).

4. Application scenarios

4.1 Engineering machinery: bucket and boom control of excavators and loaders, etc.

4.2 Manufacturing: linear drive of hydraulic presses/stamping machines, injection molding machines, etc.

4.3 Agriculture: tractor suspension systems, etc.

4.4 Aerospace: landing gear, steering gear control, etc.

Hydraulic cylinders are irreplaceable in heavy-load and precise control scenarios due to their high efficiency and reliability. In practical applications, they need to be designed comprehensively according to load, speed, environment and other conditions. For more hydraulic cylinder knowledge sharing/suggestions or if you need to purchase high-quality hydraulic presses, please feel free to tell us (scan the WhatsApp QR code below). Jianlong Hydraulic Technology will provide you with personalized, customized professional solutions and serve you wholeheartedly.