Before we talk about hydraulic cylinders we need to know what is a hydraulic cylinder? How do they work? What are they used for?
1. What is a hydraulic cylinder and how does it work?
A hydraulic cylinder is an actuator designed to provide unidirectional force through a single stroke. They find widespread applications, particularly in engineering vehicles. Hydraulic cylinders derive power from hydraulic fluid, typically oil. Consisting of a cylinder barrel and a piston rod, hydraulic cylinders facilitate movement. The ends of the cylinder are sealed by cylinder bottom (or sometimes called cylinder head) and piston rod protruding from the cylinder head. Essentially, each hydraulic cylinder has two ports for connection to pipelines. With the piston completely sealed within the barrel, positioned between the two ports, when oil enters one port, it starts pushing the piston forward, thereby moving the rod along with it. This movement transfers to the connected object. As the piston reaches the end of the cylinder, completing the stroke, the other port begins to introduce oil, pushing the piston and rod back to the initial position. This cycle repeats, resulting in the movement of the object. This constitutes the basic principle of how hydraulic cylinders operate.
2. What is the purpose of the hydraulic cylinder?
Hydraulic cylinders find applications in various fields including mold machinery, agriculture, construction, mechanical engineering, and engineering vehicles. They are ubiquitous in virtually every setting where the lifting or movement of heavy objects is required.
3. Hydraulic cylinder type?
There are many types of hydraulic cylinders, but they can mainly be classified into two categories: single-acting hydraulic cylinders and double-acting hydraulic cylinders. Single-acting cylinders only have oil entering one side to push or pull the piston and rod, utilizing their own weight or a spring to achieve the return stroke. Double-acting hydraulic cylinders have oil entering both ports, exerting pressure on both sides of the piston for pushing or pulling. Other classifications include double piston hydraulic cylinders, series hydraulic cylinders, and multistage hydraulic cylinders. Hydraulic cylinders are only suitable for pushing or pulling and should not transmit bending moments or lateral loads to the piston rod or cylinder. This design allows hydraulic actuators to move and compensates for any misalignment between the actuator and the load it is pushing. As the final actuator in the entire system, hydraulic cylinders are crucial components, and their performance directly affects the overall system performance. Therefore, understanding hydraulic cylinder knowledge is particularly important and necessary.