2022744 Original Excavator Parts Hydraulic Main Pump Cylinder Block Rotor for Hitachi ZX330-3 

The Hitachi original hydraulic main pump cylinder rotor (part number: 2022744) is the core rotating component of the Hitachi excavator axial piston hydraulic pump. According to official parts information, the rotor is mainly suitable for the Hitachi EX270-5 excavator model. Meanwhile, it may also be applicable to some models equipped with HPV145 series main pumps, such as Hitachi EX350-5 excavator. In addition, this component has universality with the main pump of 20 ton excavators such as Hitachi ZX200, ZX200LC, ZAXIS200, etc. When purchasing, it is strongly recommended that you conduct a final verification based on the specific model of the equipment, engine serial number, and complete model of the hydraulic pump (such as HPV102, HPV145, etc.) to ensure a complete match. Its associated or substitute part numbers may include 9749142, etc.
 

The cylinder rotor is the "heart" of the hydraulic main pump, and its core function is to rotate at high speed under the drive of the pump shaft. The precision machined plunger hole inside is matched with the plunger assembly, and under the action of the angle change of the inclined plate, the plunger reciprocates in the hole, thus continuously completing the oil suction and pressure process, converting the mechanical energy of the engine into hydraulic energy, and providing a stable and high-pressure oil source for all actions of the whole machine. As an original component, it is usually forged from high-strength alloy steel and undergoes precision machining, heat treatment, and surface hardening treatment to ensure extremely high dimensional accuracy, hardness, and wear resistance.

The maintenance core of the cylinder rotor is to prevent abnormal wear, maintain cleanliness, and monitor its fit clearance to ensure the efficiency and stability of the entire hydraulic system. Regular inspection and maintenance: Combined with major repairs every 2000-4000 working hours of the equipment, disassemble and inspect the hydraulic pump under professional conditions. Focus on checking the wear of the rotor column plug hole (usually measured by an inner diameter dial gauge for roundness and cylindricity), whether there are any scratches or strains on the surface, and whether the mating surface with the port plate is flat and has no erosion. Oil management: Strictly using hydraulic oil of the specified model and cleanliness level, and regularly replacing the filter element, is the most effective way to prevent impurities from entering the pump and causing rotor wear.