Basic Components Of Hydraulic System And Types Of Hydraulic System

Basic Components Of Hydraulic System

• Hydraulic Pump
• Hydraulic Cylinder And Piston
• Hydraulic tank
• Control valve
• Pressure Relief Valve
• Hose Pipe

Hydraulic Pump

There are many types of hydraulic pumps, such as gear pumps, plunger pumps, vane pumps, and screw pumps. A gear pump can flow a large amount of oil compared to a plunger pump. The basic concept of all hydraulic pumps is to displace a volume of fluid against a resistive load or pressure.

Hydraulic Cylinder

It is an bigger sized cylinder, in which pistons and connecting rods are mounted. It is also known as ram cylinder. The connecting rod transmits power from the piston to the lifting arms. The piston moves in the hydraulic cylinder and creates reciprocating motion in the cylinder. When raising the equipment the lifting arms are raised by hydraulic pressure but are lowered by their own weight.

Hydraulic Piston

The piston is attached to the piston rod and moves up and down the cylinder bore, pushed by hydraulic fluid. It provides the area used to create the hydraulic force. It is important that no hydraulic fluid can pass over the internal piston. The main function of the piston is to isolate the pressure zone inside the barrel. The piston is machined with grooves to accommodate elastomeric or metal seals and bearing elements. These seals can be single-acting or double-acting. The difference in pressure between the two sides of the piston causes the cylinder to extend and retract. The piston is connected to the piston rod by means of threads, bolts or nuts to transfer linear motion.

Hydraulic Tank

A hydraulic tank is used to store hydraulic oil for the system. In some tractors, the transmission chamber itself serves as the hydraulic tank and the same oil is used for the transmission system as well as the hydraulic system. Some tractors have a separate tank for hydraulic oil.

Hose Pipe 

Hydraulic hose pipe is used anywhere in a hydraulic system that requires a flexible connection between two fluid ports. A hydraulic hose hose pipe is a synthetic rubber tube wrapped around some form of flexible reinforcement such as metal or fiber and then covered in another rubber casing.

Control Valve

A control valve is a type of valve, which controls the movement of hydraulic oil in the desired direction, magnitude and lifting speed. Thus the control valve performs three functions

• To change the lifting direction
• To change the lifting force and
• To change the lifting speed.

Pressure Relief Valve

A pressure relief valve is used in a hydraulic system to limit the system pressure to a certain set level. If this set level is reached, the pressure relief valve responds and allows excess flow from the system back to the tank.

Working Principle Of Hydraulic System

The working principle of hydraulic system is based on Pascal's law. This law states that pressure applied to a confined fluid is transmitted equally in all directions. A small force acting on a small area can produce a high force on a large area surface

Operation Of Hydraulic System

A hydraulic pump draws oil from the oil reservoir and sends it to the control valve under high pressure. From the control valve, oil passes to the hydraulic cylinder to operate the piston, which, in turn, extends the lift arm. Lifting arms are attached with implements. The hydraulic pump is driven by suitable gears, which are connected to the engine.

Types Of Hydraulic System

• Position Control
• Draft Control

Position Control

This system maintains a constant plowing depth by automatically adjusting the draft of the tractor. In this system the control valve can be directly operated by the driver, who can lower or hold a device mounted on the linkage at any selected height.

Draft Control

In this system, the working depth of any tool can be continuously controlled without the need for a depth wheel on the tool. A hydraulic control valve reacts to changes in loading in the upper or lower links that arc due to changes in draft or pull required by the implement. Any implementation that goes too deep increases its draft. This increase is realized by top links or lower links. The control system then increases the implementation until the draft reaches the current level and the implementation returns to the original depth using the draft control system.