Hitachi Excavator Parts K5V80DTP-YXSKR-9K00 Main Pump ZX160W 9227147 Hydraulic Pump

Hitachi excavator parts K5V80DTP-YXSKR-9K00 main pump ZX160W 9227147 hydraulic pump

This is not a distinct pump type per se, but a critical control refinement applied predominantly to axial piston swashplate pumps, making them essential for efficient excavator operation. The core pump structure remains as described in the first point. The key addition is a sophisticated pressure-compensating control mechanism integrated into the swashplate angle adjustment system. This mechanism constantly monitors the outlet pressure of the pump. Its principle dictates that when the system pressure reaches a pre-set maximum (the compensator setting), the control mechanism automatically reduces the swashplate angle, thereby decreasing pump displacement (flow output). This prevents pressure from rising further, protecting the system from overload. Structurally, this involves a hydraulic compensator valve (often pilot-operated), pressure sensing lines, and the linkage connecting it to the swashplate servo piston. When downstream pressure is below the compensator setting (e.g., during digging when the cylinder is moving), the pump delivers maximum commanded flow. As resistance increases and pressure approaches the set limit (e.g., when the bucket hits an immovable object or reaches the end of its stroke), the compensator valve shifts, directing pilot pressure to the servo piston to destroke the pump, holding pressure constant while flow drops to only what's needed to compensate for internal leakage.