A hydraulic cylinder converts hydraulic energy into mechanical energy and produces linear reciprocating motion. ( or oscillating activity ) A hydraulic actuator. It features a simple structure and reliable operation. When used for reciprocating motion, it can eliminate the need for a reducer, exhibits no transmission backlash, and provides smooth movement, making it widely employed in various mechanical hydraulic systems.

The output force of a hydraulic cylinder is directly proportional to the effective area of the piston and the pressure difference across its two sides. A hydraulic cylinder essentially consists of a cylinder barrel and cylinder head, a piston and piston rod, sealing elements, a cushioning device, and an exhaust port. The cushioning and exhaust devices depend on the specific application; the other components are indispensable. Next, we will discuss two types of hydraulic cylinders.

Hydraulic cylinders come in many structural designs, and there are numerous ways to classify them: based on their mode of motion, they can be linear reciprocating or rotary oscillating; according to the hydraulic circuit, they may be single‑acting or double‑acting. By structural configuration, they include piston type, plunger type, multi‑stage telescopic sleeve type, gear‑rack type, and others. In terms of mounting style, they can be equipped with tie rods, eyelets, support feet, hinge pins, and so forth. Depending on the pressure rating, they are classified as… 16 megapascal, 25 megapascal, 31.5 Megapascals, etc.

1. Piston-type

A single-rod hydraulic cylinder has a piston rod on only one end. This diagram shows a single-rod hydraulic cylinder, with ports at both ends for fluid inlet and outlet. A 、 B It can supply either pressurized oil or return oil, enabling bidirectional motion; hence it is called a double-acting cylinder. The piston can move in only one direction, with movement in the opposite direction requiring an external force. However, its stroke is generally longer than that of a single-acting hydraulic cylinder.

Piston-type hydraulic cylinders come in single-rod and double-rod configurations, with either the cylinder body or the piston rod serving as the mounting point. Depending on the direction of hydraulic force, they can be single‑acting or double‑acting. In a single‑acting hydraulic cylinder, pressurized fluid is supplied to only one chamber; the cylinder can move in one direction under hydraulic pressure, while movement in the opposite direction is achieved by an external force. ( Such as spring force, self-weight, or external loads, etc. ) Achieved. ). However, the bidirectional movement of the piston in a double-acting hydraulic cylinder is achieved by alternately supplying oil to and exhausting from the two chambers.

It has a single piston rod on one side of the piston, so the effective cross-sectional areas of the two chambers are different. With the same oil supply, the piston’s speed varies depending on which chamber is being supplied. When the load forces to be overcome are equal, each chamber requires a different supply pressure; alternatively, once the system’s set pressure is established, the hydraulic cylinder of the sanitation garbage truck can move in both directions, accommodating varying load forces.

2. Piston-type

(1) The plunger-type hydraulic cylinder is a single-acting hydraulic cylinder; it can move in only one direction under hydraulic pressure, while the plunger returns to its original position by means of an external force or by its own weight.

(2) The piston is supported solely by the cylinder liner and does not come into direct contact with it; this design facilitates easy machining of the cylinder liner and is well suited for long-stroke hydraulic cylinders.

(3) The plunger is constantly subjected to heavy loads during operation, thus requiring sufficient rigidity.

(4) Plunger weights are often substantial; when mounted horizontally, they tend to sag under their own weight, leading to uneven wear on the seals and guides. Therefore, vertical mounting is more advantageous.