9219118 Original Excavator Hydraulic Final Drive for Hitachi ZX600

Part number 9219118 is a special hydraulic swing reduction gearbox (with integrated swing motor assembly) for Hitachi excavators ZX650/ZX600, compatible with ZX650LC-3/ZX600LC-3/ZX650H-3/ZX600H-3, as well as ZX670-3/ZX680-3 and other models. It is suitable for the hydraulic system of Isuzu 6WG1 engine, with a transmission ratio of 215:1, input torque of 1850N·m, output torque of 397750N·m, rated working pressure of 35MPa, maximum pressure resistance of 42MPa, rated speed of 2000rpm, and weight of 185kg. Adopting three-stage planetary gear transmission and integrating wet multi-disc brake, it ensures precise and stable swing action, protects the swing bearing and structural parts, and avoids impact damage.

The planetary gears are made of 20CrMnTi alloy with carburizing and quenching treatment, the tooth surface hardness is HRC58-62, with excellent wear resistance and impact resistance. The planet carrier is made of high-strength cast steel, with strong bearing capacity, suitable for heavy-duty working conditions. The friction plates of the wet brake are made of copper-based powder metallurgy material, with stable friction coefficient, rapid braking response and no obvious thermal decay. The seals are made of oil-resistant nitrile butadiene rubber (NBR) and polyurethane (PU) composite material, suitable for oil temperature environment from -30°C to 100°C, with excellent anti-aging and anti-leakage performance. The housing is made of ductile iron (QT600-3), after aging treatment, the deformation is ≤0.1mm, with strong impact resistance and vibration resistance. It is recommended to maintain every 2000 hours under normal working conditions, replace the gear oil and seals, and shorten to 1500 hours under harsh working conditions (such as mines, heavy-duty crushing). There are no failures such as gear wear, brake failure and leakage within the maintenance cycle, which effectively extends the service life of the swing mechanism and reduces the failure rate.

Adopting an integrated assembly design, special hoisting tools (load-bearing ≥200kg) are required for disassembly and installation. Before disassembly, the pressure of the hydraulic system should be released (≤0.1MPa). During installation, the flange bolts should be tightened symmetrically and evenly according to 120-140N·m. After installation, GL-5 85W-90 gear oil should be added to the oil level line, and start the test run to check the swing action, braking performance and leakage. This reduction gearbox can reduce the maintenance cost of the swing mechanism by more than 40%, reduce the downtime caused by gear wear and brake failure, improve the operating efficiency of the excavator by about 15% under working conditions such as mine stripping, large-scale earthwork and hoisting, and ensure the safe, reliable and precise swing action.