3089266 Original Excavator Hydraulic Pump Gear for ZX330

Part number 3089266 is the original hydraulic pump gear provided by Hitachi for the ZX330 series hydraulic excavator. This component is mainly used for internal transmission of hydraulic pumps, transmitting engine power to the plunger pump and driving the hydraulic system to work. It is the core transmission component that ensures the efficient and smooth operation of the pump group. Its universal models cover 30-40 ton models such as Hitachi ZX330, ZX330-5G, ZX350, ZX370, as well as other Hitachi excavators using the same series HPV145 hydraulic pump. As a standard component of the original hydraulic pump, its tooth profile, module, and installation hole position are completely matched with the pump body. It is strictly prohibited to use non-standard spare parts to avoid transmission noise, increased wear, or damage to the pump unit.

This product is a helical gear forged from high-strength alloy steel, typically made of 20CrMnTi or 42CrMo. It has undergone precision machining such as carburizing, quenching, and gear grinding, with a tooth surface hardness of HRC58-62 and good core toughness. Its modulus is about 3-4mm, the number of teeth is about 20-30, and the accuracy level reaches level 6 of GB/T 10095-2008, ensuring smooth transmission and low noise. The inner hole of the gear is connected by splines or flat keys, which tightly fit with the pump drive shaft; Phosphating or copper plating treatment is applied to the tooth surface to improve wear resistance. The working temperature range is -20 ℃ to+120 ℃, suitable for harsh environments with high temperature and high pressure in hydraulic systems.

Inspection cycle: Check every 1000 working hours or once a year. Key inspection: 1 Whether there is pitting, peeling, or cracking on the tooth surface; 2. Whether the tooth flank clearance exceeds the standard (generally 0.10-0.20mm); 3. Check if the keyway is worn or loose. Replacement timing: Replace immediately when the tooth surface wear exceeds 0.3mm, broken teeth or abnormal transmission noise occur. Disassembly and installation: 1 Remove the hydraulic pump assembly and disassemble it; 2. Use a dedicated puller to remove the old gear (to avoid damaging the shaft neck); 3. Clean the shaft neck and keyway; 4. Heat the new gear to 80-100 ℃ and assemble it (using thermal expansion and contraction); 5. After installation, cool down and check the axial clearance.