YB60000218 Genuine Hitachi rotary gearbox for Hitachi excavator ZX890-6

Part number YB60000218 is a special hydraulic swing reduction gearbox (integrated with swing motor) for Hitachi excavator ZX890-6 series, compatible with ZX890LC-6/ZX890LCH-6/ZX890LCR-6/ZX890H-6, as well as ZX690-6/ZX690LCH-6 and other models. It is suitable for the hydraulic system of Isuzu 6UZ1 engine, with a transmission ratio of 228:1, input torque of 2100N·m, output torque of 478800N·m, rated working pressure of 38MPa, maximum pressure resistance of 45MPa, rated speed of 1900rpm, and weight of 208kg. Adopting three-stage planetary gear transmission and wet multi-disc brake, it ensures precise and stable swing under heavy-duty working conditions, protects the swing bearing and structural parts, and avoids impact damage.

hardness is HRC60-64, which has better wear resistance and impact resistance than conventional materials. The planet carrier is made of high-strength cast steel (ZG35CrMo), with strong bearing capacity, suitable for mine heavy-duty working conditions. The friction plates of the wet brake are made of copper-based powder metallurgy + ceramic composite material, with stable friction coefficient, fast braking response and thermal decay rate ≤5%. The seals adopt a composite structure of fluororubber (FKM) and polyurethane (PU), suitable for oil temperature environment from -35°C to 110°C, with excellent anti-aging and anti-leakage performance. The housing is made of ductile iron QT700-2, after double aging treatment, the deformation is ≤0.08mm, with outstanding impact resistance and vibration resistance. It is recommended to maintain every 2000 hours under normal working conditions, replace the gear oil and seals; shorten to 1500 hours under harsh working conditions such as mines and large-scale 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 ≥250kg) 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 130-150N·m. After installation, GL-5 85W-140 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 45%, reduce the downtime caused by gear wear and brake failure, improve the operating efficiency of the excavator by about 18% under working conditions such as mine stripping, large-scale earthwork and hoisting, and ensure the safe, reliable and precise swing action.