Belparts excavator K5V140DT-1E05 EC250D hydraulic main pump new for volvo

Engineered for extreme durability, these pumps feature hardened alloy pistons and copper-plated rotors to withstand high-frequency excavator shocks. Integrated pressure compensation and load-sensing controls adapt to dynamic working conditions. Beyond power transmission, they maintain stable pressure via closed-loop feedback, enabling smooth coordination of lifting, slewing, and digging--even in dusty or extreme-temperature environments.

The axial piston pump with a tilting swashplate is the undisputed workhorse for primary hydraulic circuits in modern excavators. Its core principle involves multiple pistons arranged axially (parallel to the drive shaft) within a rotating cylinder block. Each piston features a slipper pad riding on a non-rotating swashplate angled relative to the drive shaft's axis. As the cylinder block rotates, the pistons reciprocate within their bores: moving outward during the half-rotation where the swashplate distance increases (suction stroke, drawing fluid from the inlet port), and being forced inward during the opposite half-rotation where the distance decreases (discharge stroke, pressurizing fluid to the outlet port). The critical structural element for variable displacement is the adjustable swashplate angle. By changing this angle (typically via a hydraulic servo piston controlled by the operator or machine electronics), the stroke length of the pistons is altered. A larger angle increases piston stroke and thus pump displacement (flow rate), while a zero angle results in zero displacement. Key structural components include the drive shaft, rotating cylinder block with precision piston bores, pistons with slippers, swashplate with tilt mechanism, valve plate (stationary, with kidney-shaped ports for inlet/outlet), and a robust housing. In excavators, this design offers exceptional efficiency across a wide operating range, precise flow control essential for coordinated multi-function operation, and high-pressure capabilities needed for digging forces. Its ability to instantly vary flow from zero to maximum based on demand is fundamental to efficient excavator power management.