Product Overview
The PVD-00B-14P-5G3-4552A is a core model within the Nachi PVD series of swashplate-type variable displacement dual axial piston pumps, specifically engineered as the main hydraulic pump for 1–2 ton class mini excavators. The PVD series features a unique “Split-Flow” design that integrates two independent piston pump sections within a single housing, delivering two equal flows from the same drive shaft to ensure synchronous supply to the left and right travel motors — guaranteeing straight-line travel of the crawler undercarriage without operator correction.
Within the PVD-00B frame, displacement variants including 11P, 12P, 14P, 15P, 16P, and 18P are available, all sharing the same rotary group and housing, differing only in the swashplate stroke limiter. The PVD-00B-14P corresponds to a total displacement of 14 cm³/rev (7 cm³/rev per section), suitable for excavators up to 2.0 tons.
About the Nachi PVD Series: The PVD series is Nachi’s dual equal-flow split piston pump platform developed specifically for mini excavators, spanning displacements from 00B (8×2) to 3B (33×2), suitable for 1–6 ton class excavators. The entire series comes standard with constant horsepower control and an internal drain structure, eliminating the need for external drain piping and adapting to compact engine compartments. PVD series pumps are the original equipment manufacturer (OEM) hydraulic pump supplier for Hitachi, Kubota, JCB, Takeuchi, Caterpillar, and other leading mini excavator manufacturers.
Model Code Breakdown (for procurement and engineering reference):
Using PVD-00B-14P-5G3-4552A as example:
PVD: Nachi split-flow dual axial piston pump series
00B: Frame size code, smallest PVD frame, suitable for ≤2.0 t excavators
14P: Maximum displacement code, 14 cm³/rev (7 cm³/rev per section). All displacement variants within the PVD-00B frame share the same rotary group and housing
5G3: Configuration code, 5 = design variant, G3 = port and control option code
4552A: Specification suffix code, identifying factory calibration parameters and batch
OEM Cross-Reference (for procurement reference):
Hitachi: 4438711 (ZX20U/ZX20UR/EX20U-3/EX20UR-3)
Kubota: RA221-61112 (U15-3/U17-3/KX36-3)
JCB: 20/925566 (8018/8018 CTS/8018Z)
Drop-in Replacement Advantage: Manufactured to exact Nachi OEM specifications, this pump achieves complete drop-in interchangeability with the original PVD-00B series for SAE B two-bolt mounting flange, 13T splined shaft, SAE standard port layout, and constant horsepower control module interface. Every pump undergoes 100% simulated load testing prior to shipment, validating 24.5 MPa pressure loading, constant horsepower control response, and volumetric efficiency under conditions replicating real-world duty cycles.
Technical Specifications
Model PVD-00B-14P-5G3-4552A:
Model Code: PVD-00B-14P-5G3-4552A
Series: Nachi PVD Series (Swashplate-Type Dual Variable Axial Piston Pump)
Frame Size: 00B
Displacement per Section: 7 cm³/rev
Total Displacement (Dual): 14 cm³/rev
Number of Piston Pump Sections: 2 (Equal Split-Flow)
Rated Continuous Working Pressure: 21 MPa (3045 psi)
Maximum Intermittent Peak Pressure: 24.5 MPa (3553 psi)
Maximum Allowable Speed: 2800 rpm
Rated Operating Speed: 2600 rpm
Minimum Speed: 900 rpm
Theoretical Flow (2600 rpm): Approx. 36.4 L/min (18.2 L/min per section)
Control Type: Constant Horsepower Control (standard), optional Power Shift control
Mounting Flange: SAE B two-bolt flange
Shaft: 13T, 7/8″ splined shaft
Rotation: Right-hand (viewed from shaft end)
Housing Material: High-strength cast iron
Seal Material: NBR (nitrile rubber), suitable for mineral oil-based hydraulic fluid
Drain Type: Internal drain structure (standard), no external drain line required
Suitable Excavator Tonnage: ≤2.0 t
Weight: Approx. 21 kg (base pump body)
Working Fluid: ISO VG32 / VG46 anti-wear hydraulic oil
Fluid Cleanliness: ISO 4406 18/15 or better
PVD Series Displacement Size Reference:
PVD-00B: 8×2 = 16 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2800 rpm, ≤1.5 t, weight approx. 21 kg
PVD-0B: 12×2 = 24 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2800 rpm, ≤2.5 t, weight approx. 28 kg
PVD-1B: 17×2 = 34 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2700 rpm, ≤3.5 t, weight approx. 33 kg
PVD-15B: 19×2 = 38 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2600 rpm, ≤4.0 t, weight approx. 38 kg
PVD-2B: 25×2 = 50 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2600 rpm, ≤5.5 t, weight approx. 44 kg
PVD-3B: 33×2 = 66 cm³/rev, rated 21 MPa, peak 24.5 MPa, max speed 2400 rpm, ≤6.0 t, weight approx. 60 kg
PVD-00B Frame Displacement Variant Reference:
PVD-00B-11P: 11 cm³/rev (5.5×2)
PVD-00B-12P: 12 cm³/rev (6×2)
PVD-00B-14P: 14 cm³/rev (7×2)
PVD-00B-15P: 15 cm³/rev (7.5×2)
PVD-00B-16P: 16 cm³/rev (8×2)
PVD-00B-18P: 18 cm³/rev (9×2)
Note: All variants share the same rotary group and housing, differing only in the swashplate stroke limiter.
Key Technical Advantages
1. Dual Equal-Flow Split Design with Straight-Line Travel Precision
The PVD series’ core technical feature is its “Split-Flow” design — integrating two independent piston pump sections within a single pump housing, delivering two equal flows from the same drive shaft. The flow deviation between the two circuits is ≤2%, ensuring synchronous supply to the left and right travel motors for straight-line travel of the crawler undercarriage without operator correction. This design fundamentally eliminates the travel deviation problem caused by flow imbalance in conventional dual-pump systems, significantly reducing operator fatigue.
2. Constant Horsepower Control with Full Engine Power Utilization
The PVD-00B-14P comes standard with constant horsepower control. As system pressure rises, the controller automatically reduces pump displacement to maintain pump input power (P×Q) within the engine’s available power range, fully utilizing engine horsepower to increase machine speed and output power. This control method effectively prevents engine stall under heavy digging loads while optimizing fuel efficiency. Optional Power Shift control provides dual power curve switching for light-load and heavy-load operating conditions.
3. Internal Drain Structure with Compact Installation Design
The PVD series features an internal drain structure as standard, where case drain oil returns directly to the suction side through internal passages without requiring external drain piping. This design significantly simplifies hydraulic system piping layout, adapting to the compact engine compartments of mini excavators. The PVD-00B base pump body weighs only approximately 21 kg, with compact dimensions, and the standardized SAE B two-bolt flange and 13T splined shaft interface require no adaptation for replacement.
4. High Power Density with Precision Swashplate Bearing System
The PVD series employs precision swashplate support structures across all frames from 00B to 3B. For the lighter PVD-00B to PVD-1B frames, the swashplate support section uses a ball structure to reduce friction and wear. Pistons and cylinder bores are precision match-ground to micron-level clearances, maintaining stable volumetric and mechanical efficiency at 24.5 MPa peak pressure.
5. Integrated Auxiliary Gear Pump Options
The PVD series offers optional integrated high-pressure auxiliary gear pumps and pilot control gear pumps. High-pressure auxiliary gear pumps supply oil to auxiliary circuits, while pilot control gear pumps provide pilot oil sources for the machine’s valve blocks. This modular design provides flexibility for mini excavator hydraulic system integration, reducing the number of independent pumps and piping connection points.
6. Wide Hydraulic Fluid Compatibility with Broad Temperature Adaptability
The PVD series is compatible with ISO VG32 or VG46 anti-wear hydraulic oils, with a viscosity range of 15–400 mm²/s, meeting the requirements of construction machinery applications under different climate conditions. The housing is precision-cast from high-strength cast iron, with the material’s damping characteristics effectively suppressing structural vibration and fluid-borne noise. The seal material is NBR (nitrile rubber), with standard configuration suitable for mineral oil-based hydraulic fluids.
Application Areas
Mini Excavators: Main hydraulic pump for 1–2 ton class mini excavators (the core application area for the PVD-00B-14P)
Small Excavators: Compatible with Hitachi ZX16/ZX17/ZX18 series, Kubota U15/U17/KX018/KX36 series, Takeuchi TB015/TB016 series, Caterpillar 301.6C/301.8C series, JCB 8018 series, etc.
Compact Construction Equipment: Small loader and small bulldozer hydraulic systems
Municipal Maintenance Equipment: Small street sweepers, municipal maintenance machinery hydraulic drives
Agricultural Machinery: Small agricultural excavators, orchard management machinery hydraulic systems
Landscaping Equipment: Mini excavators, landscaping machinery hydraulic power sources
Expert Maintenance Tips
1. Pre-Start Pump Housing Priming (Mandatory)
Before starting the engine, manually pre-fill the main pump casing with clean, fresh hydraulic fluid through its highest case drain port. Operating an axial piston pump bone-dry — even for a few seconds — will score the valve plate and piston slippers, causing immediate total pressure loss.
2. Air Bleeding & Initial Startup Procedure
After installation, loosen the air bleed port on top of the pump housing. Crank the engine with the fuel supply disabled until clear, bubble-free oil flows from the port, then retighten. Allow the machine to idle under no load for 10 to 15 minutes to clear trapped air from the main hydraulic loop.
3. System Fluid Decontamination
If replacing a pump that suffered internal mechanical failure, completely drain and clean the hydraulic oil reservoir, flush circuit lines, and clean the oil cooler. Replace all return and suction filter elements before starting the engine. System fluid cleanliness for the PVD series must meet ISO 4406 18/15 or better.
4. Relief Pressure Check
Verify system pressure relief valve settings upon startup. Incorrect pressure relief settings can lead to sluggish hydraulic controls, circuit overheating, or engine stalling under heavy digging load. The system relief pressure for the PVD-00B-14P should be set below the 24.5 MPa peak pressure.
5. Constant Horsepower Controller Setting and Adjustment
The power control curve start point of the constant horsepower controller should be calibrated according to the engine’s power characteristics. During commissioning, set the power control start point with the pump at neutral (zero displacement). The power control setting must ensure that the system does not exceed the engine’s available power at maximum working pressure, preventing engine stall under heavy load conditions.
6. Hydraulic Fluid Replacement Interval
Replace hydraulic fluid every 1,000–3,000 operating hours or every 6 months, whichever comes first. Recommended fluids are ISO VG32 or VG46 anti-wear hydraulic oils. When changing hydraulic fluid, simultaneously replace filter elements and flush the system to ensure no residual contaminants remain. Monitor oil temperature during operation, ensuring it does not exceed 80°C.
