Hitachi Construction Machinery Co. Ltd. has developed a three-pump hydraulic system for the Zaxis 345LC reduced tailswing excavator. The system delivers flow rates of 180 gallons per minute (681.4 litres per minute), distributing hydraulic flow across three separate pumps rather than conventional dual-pump layouts.

The three-pump configuration enables the system to supply oil to multiple hydraulic functions simultaneously. By splitting the hydraulic circuit across three pumps, the architecture provides additional flow capacity to support concurrent movements. This approach reduces the risk of flow starvation when operators activate multiple functions at once, such as lifting the boom, curling the bucket, and rotating the upper structure simultaneously.

The Zaxis 345LC features a reduced tailswing configuration, which limits the rear overhang of the counterweight and upper structure. This design is intended for work in confined spaces where swing clearance is limited. The three-pump system compensates for the constraints of reduced tailswing geometry by ensuring adequate flow distribution across all active hydraulic functions.

Operating three hydraulic pumps introduces additional maintenance considerations compared to conventional systems. Each pump requires periodic inspection, and oil cleanliness becomes critical, as contamination accelerates wear across all three units. The multi-pump layout also provides a degree of redundancy: if one pump develops a fault, the excavator may continue operating at reduced capacity using the remaining pumps.