9224241 Excavator Final Drive for ZX70

The original main reducer part number 9224241 is a walking reducer assembly provided by Hitachi Construction Machinery for the ZX70 series 7-ton hydraulic excavator. This reducer is mainly suitable for Hitachi ZX70-5G, ZX70-5A, ZX70-5 and other models (with a total working weight of 6.5-6.7 tons), and is a key transmission component that connects the walking hydraulic motor and the track drive wheel. Its universal model is often directly labeled as 9224241, which belongs to the planetary gear reduction mechanism. Through multi-stage planetary gear pairs, the high speed and low torque of the motor are converted into the low speed and high torque required by the track to meet the strong walking and climbing ability of the excavator in complex terrain.

This product is an original integrated walking main reducer, which adopts a three-stage planetary gear series structure, with a total reduction ratio of about 30-40:1. It can reduce the input speed of the hydraulic motor (about 2000-3000 rpm) to 50-80 rpm of the track drive wheel, while outputting torque ≥ 8000 N · m. The shell is made of high-strength ductile iron, and the key gears such as the sun gear, planetary gear, and ring gear are treated with carburizing and precision grinding. Combined with tapered roller bearings and double lip skeleton oil seals, it can withstand continuous heavy loads, impacts, and frequent starts and stops. The reducer integrates a parking brake (normally closed multi disc brake) installation interface and adopts splash lubrication method, using SAE 85W-90 GL-5 gear oil to ensure smooth, reliable and efficient transmission.

Check the reducer housing for oil leakage and cracks every 250 working hours; Check whether the gear oil at the oil level inspection plug is sufficient (the oil level should reach the middle of the inspection hole); Is the oil pipe joint loose. Operation monitoring: Monitor whether there is any abnormal metal friction or impact sound during walking; Observe whether the walking is off course or weak; Check if the track tension is normal. Fault diagnosis: If there is abnormal noise or shaking during walking, it is mostly due to gear wear, bearing damage, or poor lubrication; If there is a unilateral malfunction during walking, it is necessary to check whether the planetary carrier or gear ring inside the reducer is broken. Replacement and maintenance: Disassembly requires releasing the track tension first, and using a dedicated puller to separate the reducer from the drive wheel; When installing a new reducer, apply molybdenum disulfide grease to the spline shaft and tighten the bolts in a cross sequence and with the specified torque (usually 120-150N · m); Add the original designated model of gear oil (about 3-4L) and run it without load to evenly distribute the oil.