4403371 Original Excavator Swing Reduction Gearbox Thrust Plate for ZX160 ZX170-5A ZX190-5B ZX200 ZX

Part number 4403371 is a specialized part number for the thrust plate of the rotary reduction gearbox of Hitachi's original excavator. The thrust plate is a key pressure bearing and positioning component in the planetary gear mechanism of the rotary reducer. Its main function is to withstand the axial force generated by gear transmission, ensure stable meshing of core transmission components such as planetary gears and sun gears in the correct axial position, and adjust gear clearance, reduce friction and wear. As an original standard component, it is usually compatible with the slewing gearbox of Hitachi's multiple series of medium and large hydraulic excavators, such as the ZX series (such as ZX200, ZX240, ZX330) and EX series (such as EX200, EX300) models. This part is an important component of the overhaul package for the rotary gearbox or planetary gear assembly.

The original thrust plate is a precision machined annular or fan-shaped metal gasket, which belongs to the core positioning component of the planetary gear system of the rotary reducer. It is usually installed between the planetary carrier and the housing, or at the end of the planetary gear shaft, to precisely define the axial position of the gear, withstand and disperse the huge axial thrust generated by gear meshing. As an original component, it is made of high-strength alloy steel (such as bearing steel) and undergoes precision grinding, heat treatment (such as quenching and tempering), and surface treatment, resulting in extremely high flatness, parallelism, surface hardness, and excellent wear resistance. The precise thickness tolerance is crucial for controlling the axial clearance of gears.

The maintenance core of this thrust plate lies in regularly checking its wear condition, fitting clearance, and standardized replacement during gearbox overhaul. Inspection timing: The thrust plate is a durable component and is usually only disassembled for inspection when there is abnormal noise, weak rotation, or regular major repairs (such as every 8000-12000 working hours) in the rotating gearbox. Replacement specification: If the wear exceeds the limit or the surface is damaged, it must be replaced in groups, and the wear of the planetary gears, bearings, and housing that match it must be checked at the same time. Before installation, it is necessary to thoroughly clean the installation area to ensure that there are no impurities. During installation, the relevant bolts must be tightened in the order and torque specified in the maintenance manual, and the axial clearance of the gears must be readjusted.