3094536 Original Excavator Planetary Gear Sun Gear for ZX200

Part number 3094536 is marked as GEAR in Hitachi's original factory system; PLANETARY (planetary gear/planetary gear) is a transmission component inside the planetary gear system of a rotary motor reducer or final drive. It is specifically located on the planet carrier and serves as a planetary gear that meshes with the sun gear and rolls inside the ring gear. It is one of the core gear components for achieving "high-speed low torque → low-speed high torque". The installation platform associated with this item in the channel parts library is concentrated in the Hitachi ZAXIS-3 generation medium and large-sized machines, such as ZX200-3/ZX330-3/ZX470H-3, etc. (different batches may fall in the rotary or walking stage, depending on the assembly version).

As an original planetary gear, its main function is to withstand long-term impact torque, bending fatigue, and rolling/sliding composite friction in a sealed oil bath - tooth profile accuracy, tooth profile tolerance, tooth root fillet, and inner hole size directly determine the transmission stability, noise, heat generation, and service life of a reducer. Original factory parts are generally made of alloy steel (such as 20CrMnTi/8620 type) forging blanks, which undergo gear rolling, gear shaving/precision grinding, carburizing quenching, and tempering to obtain high surface hardness (the tooth surface often reaches HRC58-62) while maintaining toughness in the core. The inner hole and end face are precision machined according to the bearing/copper sleeve fitting tolerance, and the edges are deburred and magnetic particle inspection is used to control cracking.

It should only be operated during the overhaul of the rotary/walking gearbox. Do not disassemble it in daily life, but you can catch the signal in advance: weak climbing ability/deviation and normal motor pressure, or "slow sliding with excessive force" after the rotary brake stops, local overheating of the gearbox housing, and large amount of steel shavings (needle shaped flashing shavings) adsorbed by the magnetic screw plug - all of these indicate gear/bearing level faults. After opening the box, check three things: ① Check for pitting, pitting, peeling, plastic deformation, and tooth breakage on the tooth surface; ② Whether the common law/cross tooth thickness exceeds the tolerance (wear and thinning will increase backlash and intensify impact); ③ Whether the inner hole/copper sleeve or needle roller track is pulled or the running circle is shiny.