4461927 Original Excavator Main Pump Needle Bearing for ZX110 

The Hitachi original excavator main pump needle roller bearing (universal part number: 4461927) is a key supporting component inside the Hitachi HPV series hydraulic main pumps (such as HPV091DW, HPV0118, etc.). This original spare part is mainly suitable for multiple Hitachi ZAXIS series excavators, including but not limited to medium-sized to large models such as ZX200-3, ZX250-3, ZX330-3, ZX360-3, etc. It may also be used for other Hitachi excavator models that use the same series of main pumps.
 

The needle roller bearing is the core rotating support component of the axial piston hydraulic main pump. Its core function is to be installed between the pump shaft and the housing, to withstand the radial load generated by the high-speed rotation of the pump shaft, ensure the smooth and precise operation of the plunger cylinder assembly, and minimize frictional resistance. As an original component, it is usually made of high carbon chromium bearing steel (such as GCr15), which has undergone precision grinding and special heat treatment, and has extremely high hardness, wear resistance, and fatigue strength.
 

To ensure the long-term reliable operation of the needle roller bearing and main pump, strict preventive maintenance is required. It is necessary to maintain a high level of cleanliness in the hydraulic oil and regularly replace the hydraulic oil and filter element (recommended every 500 hours of operation) to prevent metal debris and other pollutants from entering the bearing raceway and causing abnormal wear. It is recommended to check the clearance (normal range is usually 0.02-0.05 millimeters) and rotational flexibility of the bearings every 1000 hours of operation or during pump overhaul, and observe for pitting, peeling, or overheating discoloration.