The hydraulic pump is a power component of the hydraulic system. It is driven by an engine or an electric motor to draw oil from the hydraulic oil tank to form a component that is discharged to the actuator. The hydraulic pump is divided into a gear pump, a plunger pump, a vane pump and a screw pump according to the structure.

hydraulic pump how it works,A hydraulic component that provides pressurized liquid to a hydraulic drive and is a type of pump. Its function is to convert the mechanical energy of a power machine (such as an electric motor and an internal combustion engine) into the pressure energy of a liquid. There are many factors affecting the service life of the hydraulic pump. In addition to the design and manufacturing factors of the pump itself, it is also related to the selection of components related to the pump (such as couplings, oil filters, etc.) and the operation during the test run.

The working principle of the hydraulic pump is that the movement brings about a change in the volume of the pump chamber, so that the fluid is compressed to make the fluid have pressure energy.

The necessary condition is that the pump chamber has a sealed volume change.

Types of commonly used hydraulic pumps:

1, according to whether the flow can be adjusted can be divided into: variable pump and quantitative pump. The output flow can be adjusted as needed, called the variable pump, and the flow cannot be adjusted, called the fixed pump.

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

Gear pump: small volume, simple structure, less cleanliness of oil, cheaper price; but the pump shaft is unbalanced, wear is serious, and leakage is large.

Vane pump: divided into double-acting vane pump and single-acting vane pump. The pump has uniform flow, stable operation, low noise, high pressure and volumetric efficiency compared to the gear pump, and the structure is more complicated than the gear pump.

Hydraulic pump internal structure

Piston pump: high volumetric efficiency, small leakage, can work under high pressure, mostly used in high-power hydraulic system; but the structure is complex, material and processing precision requirements are high, the price is expensive, and the cleanliness of oil is high.

There are many famous hydraulic pump brands, such as 

Parker; rexroth;stauff;hydac;atos;aeroquip;vickers;moog; hawe; kawasaki, eaton,kyb, sumitomo,nachi; uchida and so on.

The hydraulic pump assembly that we have as following for construction machines:

KOBELCO: SK135SR-2, SK135-8, SK200-6, SK200-6E, SK200-8, SK230-6, SK330-6E, SK320-6, SK350-8 and so on.

HITACHI: EX200-5, EX220-5, ZX200, Z230, ZX330-1,ZX330-3,ZX870-3 and so on.

SUMMITOMO: SH240-3, SH240-5, SH350-5 and so on.

VOLVO: EC130, EC210, EC210B, EC240, EC240B, EC290, EC290B, EC460 and so on.

CATERPILLAR:CAT312, CAT320, CAT320B, CAT320C, CAT330C and so on.

KOMATSU: PC200-7, PC200-8, PC220-7, PC220-8, PC300, PC300-7, PC400, PC400-7 and so on.