Nachi UVN-1A Vane Pump Combination | UVN-1A-0A4-1.5-4-12 Energy Saving Pump

The UVN Series (specifically focusing on the UVN-1A platform) energy-saving combination hydraulic vane pumps manufactured by Chengyuan Hydraulic are ultra-low-noise integrated fluid power configurations engineered to match official Nachi (Fujikoshi) industrial standards. Specially customized for machine-tool chuck clamping, highly localized HPUs, plastic injection mold holding, and automation utility loops, this advanced configuration seamlessly blends a high-pressure low-flow cartridge and a low-pressure high-flow element alongside an onboard mechanical unloading valve and checking components. The technical profile supports direct selection across complete engineering block codings—including base layout groups UVN-1A-0A2, 0A3, 0A4, 1A2, 1A3, 1A4, 2A2, 2A3, and 2A4—up to the fully motored smart delivery assembly UVN-1A-0A4-1.5-4-12 (integrating a dedicated 1.5 kW electric motor and a high-response variable pressure control assembly). Operating with combined dual-pump delivery during fast-forward low-resistance cycle segments, the system automatically shunts high-volume fluid back to the reservoir via the internal unloading valve once resistance matches the preset limit, anchoring long-term system hold-pressure solely via the low-volume cartridge. Every single UVN-1A combination pump undergoes 100% simulated dual-stage pressure alternation checks, unloading valve response dead-band verification, and acoustic emission dBA calibration prior to shipment to match official standards, delivering proven 100% original-place interchangeable compatibility.

Technical Specifications :

• Core Product Series: Nachi UVN-1A Template Low-Noise Integrated Monoblock Combination Vane Pumps

• Model Configurations Supported: UVN-1A-0A2 / 0A3 / 0A4 / 1A2 / 1A3 / 1A4 / 2A2 / 2A3 / 2A4

• Full-Specification Representative Unit: UVN-1A-0A4-1.5-4-12

• Dual-Cartridge Combined Displacement Codings (Prefix Markers 0 / 1 / 2):

  • Configuration Code 0: Low-volume backup displacement ranges from 2.0 to 4.0 $cm^3/rev$

  • Configuration Code 1: Mid-volume alternative displacement ranges from 6.0 to 8.0 $cm^3/rev$

  • Configuration Code 2: Large-volume primary displacement, explicitly tailored to high-speed machine actuator strokes.

• Unloading Valve Cracking Pressure Classifications (Suffix Markers 2 / 3 / 4):

  • Pressure Code 2: Low-range unloading setting threshold (typically adjusted between 1.5 – 3.5 MPa)

  • Pressure Code 3: Mid-range unloading setting threshold (typically adjusted between 3.5 – 5.5 MPa)

  • Pressure Code 4: High-range unloading setting threshold (maximizing continuous pressure up to 7.0 MPa / 70 bar / 1015 psi)

• Electric Motor Power Rating Matching (Code 11-Digit Sample 1.5): Pre-fitted with a 1.5 kW 3-phase asynchronous high-efficiency electric motor (rated continuous rotational velocity of 1450 rpm @ 50Hz)

• Fluid Interface Layout: Standard SAE threaded process ports or dedicated flat face flange connections (fully separating suction from internal case drainage pathways)

• Acoustic Sound Emission Threshold: Operates at $\le 53\text{ dB(A)}$ under full high-pressure hold cycles (premium indoor quiet room metric)

Key Technical Advantages:

• Monoblock Monoblock Housing with Integral Unloading Valves: Rather than utilizing clumsy external pipe fittings to bridge two single pumps, the UVN-1A contains both high and low-flow rotor-stator cartridges inside a single high-density cast-iron pump frame. A mechanical self-piloted unloading valve is cast directly into the rear manifold cap. This design eliminates complex external plumbing arrays, reducing physical envelope volume by 40% and eliminating cross-joint external oil leakage vectors.

• Intra-Vane Geometry with Hydrostatically Balanced Tracking: The internal pumping cores leverage an intra-vane layout where secondary pilot channels inject pressure beneath the vane tips. This design counterbalances the dynamic forces generated where the vanes track the cam ring’s inner contour. This configuration minimizes mechanical chatter at high frequencies, flattening flow delivery pulsations and preserving a volumetric efficiency of 92% under extended 7.0 MPa holding states.

• Shockless Geometric Throttling Grooves for Acoustic Suppression: Developed explicitly for noise-critical plant applications, the UVN internal timing plates feature mathematically optimized shockless decompression slots. As the rotor indexes under high speed, oil transition vectors between the vane slots undergo smooth pressure gradients, eliminating high-frequency whistling noises and keeping acoustic emissions around 53 dB(A).

• Direct-Coupled Zero-Error Monoblock Alignment: On complete units like the UVN-1A-0A4-1.5-4-12, the hardened input drive shaft locks directly into the hollow output shaft of the electric motor without intermediate generic couplings. This monoblock assembly secures total axial concentricity, preventing mechanical vibrations caused by coupling backlash or alignment drift. This design significantly extends the service life of the forward double-lip shaft seals.

Application Areas:

• High-Precision CNC Machine Tools & Turning Centers: Direct power generation for high-pressure hydraulic latches, indexing turret tool locks, and automated jig fixtures on machining centers.

• Automated Shoemaking & Fast Light-Industrial Presses: Precise clamp lock holding on multi-station automated injection shoemaking machines and sole-press machinery.

• Low-Pressure High-Volume Low-Noise Fluid Power Units: Centralized master pilot control fluid distribution networks handling high-density manufacturing assembly lines.

Expert Maintenance Tips:

• Mandatory Pump Housing Priming Prior to First Electrical Activation: Vane pumps rely explicitly on rotational centrifugal force to throw the vanes outward to seal against the cam ring contour during startup. You must remove the top filler plug and fill the pump casing with clean hydraulic oil while rotating the shaft by hand before flipping the breaker. Use short electrical jogs (Start-Stop method) during initial startup to clear air lines and avoid dry friction scuffing on the cam ring.

• Enforce Low Vacuum Suction Limits via Oversized Intake Plumbing: Because the UVN series uses high-precision low-noise clearances, it is highly sensitive to intake restriction. The intake suction line diameter must exceed the pump inlet port dimension. Keep line lengths under 1 meter and avoid sharp 90-degree elbows. Use an intake strainer rated at $100-150\text{ }\mu\text{m}$ with ample flow capacity. Restricting intake flow will cause cavitation, resulting in sharp metallic popping sounds and severe delivery drops.

• Schedule Regular Unloading Valve Audits to Prevent Thermal Overheating: The primary energy-saving mechanic of this combination pump relies on dumping high-volume fluid once the pressure target is reached. If the HPU experiences rapid thermal oil temperature spikes while idle (holding state), connect a pressure gauge to audit the unloading valve settings. If the unloading threshold drifts or debris jams the valve core, the high-flow pump will continuously drag under high load, causing intense fluid shear heating.