AP2D36 Hydraulic Piston Pump
1. Product Overview
AP2D36 is a tandem variable displacement swashplate axial piston pump, originally developed by Uchida/KYB. It is widely used as the main hydraulic power unit for 7–8 ton compact excavators.
This integrated pump combines variable piston main pump and built-in fixed displacement pilot gear pump. Multiple control configurations are available, including mechanical negative flow control and electromagnetic proportional control. Aftermarket interchange replacement pumps are available as economical alternatives for equipment overhaul.
Model Code Explanation
- AP2D: Series designation of Uchida open-circuit tandem axial piston pump
- 36: Theoretical displacement 36 cc/rev for each piston pump
- Optional suffix letters: Represent rotation direction, shaft spline specification, control valve type and port arrangement
2. Main Technical Parameters
Item Specification
Pump Type Tandem variable displacement swashplate axial piston pump (with built-in pilot pump)
Single pump displacement 36 cc/rev
Rated Working Pressure 25.5 MPa
Maximum Peak Pressure 30 MPa
Operating Speed Range 600 ~ 2200 rpm
Volumetric Efficiency ≥91% under rated working condition
Control Mode Negative flow control / Solenoid proportional control (optional)
Shaft Specification Multiple spline options to match different excavator brands
Applicable Fluid ISO VG46, VG68 anti-wear hydraulic oil
Operating Temperature -20℃ ~ +85℃
Standard Seals NBR; FKM high-temperature sealing kit optional
3. Working Principle
Engine drives the main shaft and cylinder block assembly to rotate. The reciprocating motion of pistons sucks hydraulic oil and delivers high-pressure oil to hydraulic circuits.
The regulator adjusts the tilt angle of swashplate automatically according to system load, changing pump displacement to regulate output flow.
The integrated pilot gear pump provides stable pressure oil for main pump control valves, travel motor brakes and operating pilot circuits.
4. Core Advantages
1. Compact integrated tandem structure, main pump and pilot pump combined into one assembly, saving installation space for compact excavators.
2. Mature load-sensing control logic, stable flow output and smooth excavator composite movements.
3. Optimized internal friction pairs, low internal leakage and reliable continuous operation.
4. Complete structural variants to match Caterpillar, Doosan, Kobelco, Yanmar, Hitachi and other mainstream compact excavators.
5. Convenient disassembly and maintenance; abundant spare parts available in the market.
6. Cost-effective aftermarket replacement solution with shorter lead time compared with original OEM pumps.
5. Application Range
Serves as main hydraulic pump for 7–8 ton crawler compact excavators.
Typical compatible machine models:
Caterpillar 307C, 308C;
Doosan DH80, DX80;
Kobelco SK70, SK75;
Yanmar Vio75;
Hitachi ZX60, ZX70;
Other domestic brand 7/8-ton excavators adopting AP2D36 hydraulic system.
