Working principle of excavator hydraulic pump and types of commonly used hydraulic pumps

The Hydraulic Pump is the power component in the hydraulic system. It is driven by the engine or motor, sucks oil from the oil tank, forms pressure oil, and then discharges it to the actuator. The hydraulic system of the excavator is a combination of various Hydraulic Components connected by pipelines according to the transmission requirements of the working device of the excavator and each mechanism. So what is the working principle of the excavator hydraulic pump?

　　 Working principle of hydraulic pump of excavator

The hydraulic system of the excavator is composed of some basic circuits and auxiliary circuits, including working circuit, pressure limiting circuit, unloading circuit, buffer circuit, throttle speed regulating and throttle speed limiting circuit, walking speed limiting circuit and pilot valve control circuit Wait. Its components are mainly composed of working pump, charge pump, pilot Control Valve, distribution valve, safety valve, boom cylinder, arm cylinder, bucket cylinder, fuel tank and related pipelines.

During the working process of the hydraulic system of the excavator, the hydraulic oil is sucked from the bottom of the oil tank through the oil filter by the working pump, and the hydraulic oil with a certain pressure is output from the oil pump into a group of parallel distribution valves. The corresponding action is realized through the handle → pilot valve → working valve group. The system limits the total pressure of the entire system through the total safety valve on the main oil circuit. The safety valves of each group of working oil circuit respectively protect and replenish the corresponding oil circuit effect.

　　 Types of commonly used hydraulic pumps

1. According to whether the flow can be adjusted, it can be divided into: variable pump and quantitative pump. The output flow can be adjusted according to needs called variable pump, the flow can not be adjusted is called fixed pump.

2. According to the commonly used pump structure in hydraulic system, it is divided into three types: gear pump, vane pump and plunger pump.

Gear pump: Smaller volume, simpler structure, less strict requirements on oil cleanliness, and cheaper price; but the pump shaft suffers from unbalanced force, serious wear, and large leakage.

Vane pump: divided into double-acting vane pump and single-acting vane pump. This pump has uniform flow, smooth operation, low noise, higher operating pressure and volumetric efficiency than gear pumps, and more complex structure than gear pumps.

Plunger pump: high volumetric efficiency, small leakage, can work under high pressure, mostly used in high-power hydraulic systems; but the structure is complex, the requirements for materials and processing accuracy are high, the price is expensive, and the cleanliness of oil is required.

Generally, the plunger pump is used when the gear pump and vane pump cannot meet the requirements. There are some other types of hydraulic pumps, such as screw pumps, etc., but the application is not as common as the above three.

The knowledge of the working principle of the hydraulic pump of the excavator and the types of commonly used hydraulic pumps are introduced here for everyone. Everyone knows the excavator, but most people may not know the hydraulic pump of the excavator. I believe that through the introduction of this article, Everyone should have a certain understanding of the excavator hydraulic pump!