YB00001137 Original Excavator Parts Housing Gear for ZX330-3

The part number YB00001137 is the original housing gear (usually referring to the gear in the walking gearbox or rotary gearbox) that Hitachi Construction Machinery provides for the ZX330-3 series 32 ton medium-sized hydraulic excavator. This component is mainly used for the internal transmission system of the gearbox, converting the high-speed low torque of the hydraulic motor into low-speed high torque of the driving wheel/rotating ring gear. Its universal models cover Hitachi ZX330-3, ZX330-5G, ZX350-3 and other 30-35 ton models, as well as some EX330-3 and EX350-3 equivalent platform excavators. As an original high-precision transmission gear, its module, tooth profile, heat treatment process are precisely matched with the gearbox housing. It is strictly prohibited to use non-standard spare parts to avoid transmission noise, efficiency reduction, or damage to the casing.

This product is an original alloy steel gear, usually made of 20CrMnTiH or 20CrNiMo, treated with carburizing quenching and gear grinding process. Typical technical parameters: modulus 6-10, number of teeth 20-40, pressure angle 20 °, helix angle 15-25 °, tooth surface hardness HRC58-62, core hardness HRC30-35. The gear accuracy level is ISO 6-7 (equivalent to the national standard GB/T 10095 6-7), and the tooth surface has undergone shot peening strengthening treatment, with a fatigue life of ≥ 10 ⁷ cycles. Its installation aperture is 80-120mm, keyway width is 20-30mm, in compliance with JIS B 1702, GB/T 10095 and other standards, and can operate stably under maximum torque of 15-25kN · m and speed ≤ 3000rpm.

Disassembly inspection: Before replacement, the hydraulic system pressure must be released and the outside of the gearbox must be cleaned. After disassembling the box, check for pitting, peeling, and cracks on the gear tooth surface, measure the tooth flank clearance (standard value 0.10-0.20mm) and tooth tip circular runout (tolerance ≤ 0.05mm). Installation points: 1 Heat the gear to 80-100 ℃ (using oil bath or induction heating); 2. Align the shaft key with the keyway, press it into the shaft shoulder by hand, and avoid tapping during installation; 3. Tighten the fixing bolts step by step in a cross sequence (usually with a torque of 120-150N · m); 4. After installation, manually rotate the input shaft several times to check whether the engagement is smooth and whether there is any jamming. Lubrication and operation: Add designated gear oil (model GL-5 85W-140, capacity 15-20L), start the engine and idle for 20 minutes, monitor for any abnormal noise inside the box.