Excavator SK330-8 SK350-8 Main Pump Assembly K5V140DTP-NOSER-YTOKHV For Kobelco

Belparts excavator SK330-8 SK350-8 main pump assembly K5V140DTP-NOSER-YTOKHV for kobelco

External Gear Pump:
A fundamental and robust design frequently employed in excavators for lower-pressure auxiliary circuits, pilot control systems, and charge pumps for closed-loop systems. Its operating principle is elegantly simple: two identical gears, one driven (usually by the engine) and one idler, mesh tightly within a precisely machined housing cavity. As the gears rotate, teeth unmesh on the inlet side, creating expanding volume cavities that draw fluid in. The fluid is trapped between the gear teeth and the pump housing as the gears rotate. This trapped fluid is carried around the periphery of the housing to the outlet side. On the outlet side, the meshing of the gear teeth reduces the volume between them, forcibly ejecting the fluid under pressure. Key structural elements include the driving and driven shafts, the gear pair (often hardened steel), the pump housing with precisely machined side plates (wear plates) to minimize axial leakage, and inlet/outlet ports. While primarily fixed displacement, flow can be varied by changing the pump's drive speed. External gear pumps are prized for their simplicity, compactness, low cost, reliability, tolerance to contamination compared to piston pumps, and good performance at medium pressures.