The hydraulic pump of the excavator is the core component of the entire hydraulic system. It is responsible for converting mechanical energy into hydraulic energy and providing power for various actions of the excavator.
The working principle of the hydraulic pump is mainly based on Pascal's law, that is, the liquid pressure in a closed container is equal everywhere and transmitted in all directions. When the engine drives the shaft of the hydraulic pump to rotate, the plunger, gears or blades inside the hydraulic pump will move accordingly, thereby changing the volume of the pump chamber.
During the oil suction process, the volume of the pump chamber increases, forming a local vacuum, so that the hydraulic oil is sucked into the pump chamber from the oil tank under the action of atmospheric pressure. At this time, the hydraulic oil fills the pump chamber and prepares for the next oil pressure process.
During the oil pressure process, the volume of the pump chamber decreases and the hydraulic oil is compressed. Since the outlet of the hydraulic pump is connected to the pipeline of the hydraulic system, as the volume of the pump chamber decreases, the pressure of the hydraulic oil gradually increases. When the pressure increases enough to overcome the resistance in the hydraulic system, the hydraulic oil will be pressed into the pipeline of the hydraulic system and flow to various actuators, such as hydraulic cylinders and hydraulic motors.
The displacement of the hydraulic pump is an important indicator to measure its working capacity. Displacement refers to the volume of hydraulic oil discharged by the hydraulic pump per revolution. The larger the displacement, the more hydraulic oil the hydraulic pump discharges per unit time, and the greater the power it can provide to the hydraulic system.
In order to meet the needs of excavators under different working conditions, hydraulic pumps usually use variable control technology. By changing the displacement of the hydraulic pump, the flow and pressure of the hydraulic system can be adjusted to achieve the control of various movement speeds and forces of the excavator. For example, when excavating light-load materials, the displacement of the hydraulic pump can be reduced, the flow and pressure can be reduced to improve fuel economy; when excavating heavy-load materials, the displacement of the hydraulic pump can be increased, the flow and pressure can be increased to obtain greater excavation force.
For second-hand dealers, it is very important to understand the working principle of the excavator hydraulic pump. When purchasing a second-hand excavator, second-hand dealers need to carefully check the hydraulic pump to determine whether its working condition is normal. The performance of the hydraulic pump can be evaluated by observing whether the appearance of the hydraulic pump is damaged or leaking, listening to whether the operating sound of the hydraulic pump is abnormal, and checking whether the pressure and flow of the hydraulic system meet the requirements. When selling used excavators, second-hand dealers can introduce the working principle and maintenance methods of hydraulic pumps to customers to help customers better understand the equipment and extend the service life of the equipment.
In short, the working principle of the excavator hydraulic pump is to convert mechanical energy into hydraulic energy and provide power to the hydraulic system through the oil suction and oil pressure process. Understanding the working principle of the hydraulic pump is essential for the correct use and maintenance of the excavator, and it also helps second-hand dealers better evaluate and sell used excavators.