Why is hydraulics used in making jacks?
The word hydraulic means the flow of liquid movement. Due to the rusting properties of water, oil is used as an energy carrier in industries. Liquids can be considered incompressible and can be used to transform and transfer work. Fluids are used in many industrial processes to transfer power at a low cost and with high accuracy. The use of pressurized fluid in power transmission and control is expanding in all branches of industry. The use of fluid is divided into two categories: hydraulic and pneumatic. Hydraulic systems are used in cases where high power and controlled speeds are required. from pneumatics in cases where relatively low force and high movement speeds are required.
Hydraulic and pneumatic systems have fewer parts than other mechanical systems, and linear or rotary movements with high power and proper control can be achieved at any point. Power transmission is done by high-pressure fluid flow in transmission lines. But in mechanical systems, components such as cams, gears, etc. are used to transmit power. Hydraulic systems are flexible and there are no restrictions on the place that exists for installing other systems.
In hydraulic systems, high and accurate force can be achieved by applying low force. Large output forces can be controlled by applying a small amount of force. Since the past, hydraulic power has been used to facilitate the lifting and lowering of heavy machinery. Hydraulic jacks are used in special forms of tunnel lining and climbing. For more information, it should be said that tunnel lining is a special mold that is specially designed and produced for concrete linings of tunnels, channels and different sections.
How hydraulic systems work
The hydraulic cylinder is a mechanical actuator that provides motion and linear force transmission in the system without the need for a mechanical gear by transferring pressure from the fluid. The next step is to transfer the power to the desired point. This is the duty of pipes, hoses and fasteners. After controlling the pressure and determining the flow direction by the valves, the fluid under pressure is directed to the actuators. As a result, fluid power is converted into required mechanical power. It should be said that the working process of all hydraulic systems is based on Pascal's law. According to this law, the pressure is the same from end to end of a fluid and it enters perpendicularly. In physics, pressure is equal to force divided by unit area. Therefore, a small cross-section requires less force and a larger cross-section requires more force. However, by creating a small force on a small cross-sectional area, we will overcome a large force on a larger cross-sectional area.

What is a hydraulic jack?
In hydraulic jacks, oil is used as a power transmission. Due to the very low compressibility of liquids, the speed of hydraulic jacks can be controlled and have high power. Each jack has a shell or cylinder inside which the piston moves back and forth. The piston is attached to a handle that protrudes from one side of the cylinder. Depending on the type of jack, one or two ducts are made on the side of the cylinder head and bottom. It should be said that the fact that oil is incompressible is used in the hydraulic jack structure. Due to its incompressibility, the oil transmits the force on itself.
Hydraulic jacks do a lot of useful work with high efficiency while being simple. In this way, when a force is applied to the oil in a small cylinder, this force transfers the incompressible oil to the large cylinder. The oil presses on the piston of the large cylinder and causes the load on the cylinder to rise. In general, it can be said that the pressure on the small piston is directly transferred to the big piston and pushes it upwards. Generally, the hydraulic jack is responsible for converting hydraulic energy into mechanical energy.
Hydraulic jacks are divided into two categories:
1) One-way jacks
This jack has only one hydraulic oil inlet port. This type of jack is opened under the influence of external forces such as weight and spring force. 2) Two-way jacks This type has two hydraulic oil inlet and outlet ports. is As a result, the oil is transferred to the front and back of the piston and the jack moves. One of the advantages of hydraulic systems over other systems (mechanical or electronic) is simple design, high efficiency, ability to increase power, and control accuracy. Compared to other systems (mechanical and electrical), hydraulics are simpler, more durable and more powerful.

Advantages of using hydraulic jacks:
1. Their design is simple and easy to use.
2. have less weight than other jacks. Hydraulic jacks have different designs.
3. need little space to function.
4. can be said to be the best option for moving and lifting heavy objects.