Language
Country/Area
No result found
The mysterious power of the hydraulic cylinder: Why is it called a mechanical muscle?
A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that provides a force in one direction through a one-way stroke. This technology is widely used in engineering vehicles, manufacturing machinery, elevators and civil engineering, and plays a key role. The working principle of hydraulic cylinders is similar to that of muscles. When the hydraulic system of a machine is activated, the hydraulic cylinder is responsible for achieving movement, which is why it is called "mechanical muscle".
How is energy in a hydraulic system converted into mechanical motion?
Principle of Operation
The power of a hydraulic cylinder comes from pressurized hydraulic oil, a liquid that is not easily compressed. The most common liquid used in hydraulic cylinders is oil. A hydraulic cylinder consists of a barrel with a piston connected to a rod that can move back and forth inside the barrel. The cylinder barrel is closed at one end by the cylinder base (also called the cap), and at the other end is the cylinder head (also called the gland), even if the piston rod extends from the cylinder. The piston is equipped with sliding rings and sealing devices, which divide the interior of the cylinder into two chambers, namely the bottom chamber (cap end) and the piston rod side chamber (rod end/head end).
Relationship between hydraulic pump and hydraulic cylinder
The hydraulic cylinder is the actuator or "motor" part of the hydraulic system, while the hydraulic pump is the "generator" of the system. The pump delivers a fixed or regulated flow of oil to the hydraulic cylinder to push the piston. Common hydraulic pumps include hand pumps, air-driven pumps, and electric pumps.
Application Scope
Hydraulic cylinders are widely used in machines that require high forces, such as earth moving equipment (excavators, backhoes and tractors, etc.) to raise or lower components such as booms, arms and buckets. In the manufacturing industry, hydraulic cylinders are also used in bending machines, metal sheet shears and in pressing particleboard or plywood.
Components of a hydraulic cylinder
Cylinder
The main function of the cylinder is to contain the pressure inside the cylinder. Usually made of polished seamless steel pipe. The cylinder surface is smooth and wear-resistant, effectively supporting the operation of the piston.
Cylinder bottom or cover
The main function of the cover is to close one end of the pressure chamber and can be used as a mounting part of the cylinder. Usually fixed to the cylinder body by welding, threading or bolting.
Piston
The piston is used to separate the pressure areas in the cylinder. Its design enables the piston to operate effectively under high pressure.
Piston rod
The piston rod is made of cold-rolled steel with hard chrome plating, connected to the piston and extends from the cylinder head to connect to the workpiece.
Sealing device
The sealing device is used to prevent the leakage of hydraulic oil along the interface of the piston rod and plays a key role in the sealing groove in the cylinder head.
Application of various sealing materials
Different sealing materials are suitable for different application scenarios. Nylon, polyurethane and fluorocarbon materials are common choices. They can withstand different hydraulic working pressures and temperatures.
Working design of hydraulic cylinder
Hydraulic cylinders are available in single-acting and double-acting designs. Single-acting cylinders are generally more economical. They pump liquid to extend the piston and retract it through external force or gravity. Double-acting cylinders have oil inlets at both ends to control the extension and retraction of the piston.
Types of Structural Design
The structural design of hydraulic cylinders is mainly divided into two types: tie rod type and welding type. Tie rod hydraulic cylinders are connected to the end caps through solid threaded steel rods, which is convenient for maintenance and service; while the welded type has a more compact structure and is suitable for use in places with limited space.
The importance of hydraulic cylinders in heavy machinery construction is self-evident, but where will future technological developments take this technology?
