V38SAJS-ARX-80S21 V70SAJS-ARX-20 Daikin Piston Pump 28MPa

Product Overview

The V38SAJS-ARX-80S21, V70SAJS-ARX-20, and V70A3RX-60RC are core models within the Daikin V series and VZ series of swashplate-type variable displacement axial piston pumps. The V series is Daikin’s flagship product platform in industrial hydraulics, spanning displacements from 8 to 69.8 cm³/rev, suitable for machine tools, forging equipment, plastic molding machines, and other industrial hydraulic systems. The VZ series is the high-pressure, high-density extension of the V series, spanning displacements from 50.2 to 135.9 cm³/rev with rated pressures up to 28 MPa, suitable for large hydraulic presses, die-casting machines, marine, and metallurgical equipment requiring heavy-duty industrial operation.

V Series Core Features: Unique swashplate angle variation function; low noise operation across the entire pressure range; small power loss reduces oil temperature rise, allowing smaller tank designs; multiple control methods can be integrated into systems for energy savings, compactness, and cost reduction; high reliability, high responsivity, high stability, and long service life enhance main machine reliability; widely used in machine tools, forging presses, plastic molding machines, and more.

Model Code Breakdown (for procurement and engineering reference):

Using V38SAJS-ARX-80S21 as example:

• V38: V series, nominal size 38, geometric displacement 37.7 cm³/rev

• SAJS: Control method — Power-Match Control. SA = power limiting control, JS = additional function code. Automatically reduces flow as load increases to prevent motor overload

• ARX: Port and piping direction code. A = pressure compensator control, R = clockwise rotation (viewed from shaft end), X = side port

• 80: Design series number

• S21: Additional configuration code

Using V70SAJS-ARX-20 as example:

• V70: V series, geometric displacement 69.8 cm³/rev

• SAJS: Power-Match Control

• ARX: Pressure compensator control, clockwise rotation, side port

• 20: Design series number

Using V70A3RX-60RC as example:

• V70: V series, geometric displacement 69.8 cm³/rev

• A3: A = pressure compensator control (mechanically adjusted), 3 = pressure adjustment range 3.5–21 MPa

• RX: Clockwise rotation, side port

• 60: Design series number

• RC: With remote control system, enabling remote pressure adjustment via pilot valve

Drop-in Replacement Advantage: Manufactured to exact Daikin OEM specifications, these pumps achieve complete drop-in interchangeability with the original V series and VZ series for mounting flange, shaft dimensions, port layout, and control module interface. Every pump undergoes 100% simulated load testing prior to shipment, validating rated pressure loading, variable control response, and volumetric efficiency under conditions replicating real-world duty cycles.

Technical Specifications 

Model V38SAJS-ARX-80S21:

• Model Code: V38SAJS-ARX-80S21

• Series: Daikin V Series (Variable Axial Piston Pump, Swashplate Design)

• Geometric Displacement: 37.7 cm³/rev

• Maximum Operating Pressure: 25 MPa (250 kgf/cm²)

• Permissible Speed Range: 500–1800 r/min

• Theoretical Flow at 1800 rpm: 68.0 L/min

• Control Type: SAJS — Power-Match Control

• Rotation: Clockwise (viewed from shaft end)

• Piping Direction: Side port

• Housing Material: Cast Iron

• Hydraulic Fluid Compatibility: Petroleum-based (no designation); W = water-glycol; F = phosphate ester

• Noise Level: ≤70 dB(A)

• Weight: Approx. 24.4–26 kg (per control configuration)

Model V70SAJS-ARX-20:

• Model Code: V70SAJS-ARX-20

• Series: Daikin V Series (Variable Axial Piston Pump, Swashplate Design)

• Geometric Displacement: 69.8 cm³/rev

• Maximum Operating Pressure: 21 MPa (210 kgf/cm²)

• Permissible Speed Range: 500–1800 r/min

• Theoretical Flow at 1800 rpm: 126.0 L/min

• Control Type: SAJS — Power-Match Control

• Rotation: Clockwise (viewed from shaft end)

• Piping Direction: Side port

• Housing Material: Cast Iron

• Noise Level: ≤71 dB(A)

• Weight: Approx. 55 kg

Model V70A3RX-60RC:

• Model Code: V70A3RX-60RC

• Series: Daikin V Series (Variable Axial Piston Pump, Swashplate Design)

• Geometric Displacement: 69.8 cm³/rev

• Pressure Adjustment Range: 3.5–21 MPa (35–210 kgf/cm²)

• Permissible Speed Range: 500–1800 r/min

• Theoretical Flow at 1800 rpm: 126.0 L/min

• Control Type: A3 — Pressure Compensator Control (mechanically adjusted), with remote control system (RC)

• Rotation: Clockwise (viewed from shaft end)

• Piping Direction: Side port

• Housing Material: Cast Iron

• Noise Level: ≤71 dB(A)

• Weight: Approx. 55 kg

V Series Displacement Size Reference:

• V8: 8.0 cm³/rev, max pressure 7 MPa, flow 13.5 L/min @1800rpm, noise ≤68 dB

• V15: 14.8 cm³/rev, max pressure 21 MPa, flow 26.6 L/min @1800rpm, noise ≤69 dB

• V15 (Type Y): 14.8 cm³/rev, max pressure 7 MPa

• V23: 23.0 cm³/rev, max pressure 25 MPa, flow 41.4 L/min @1800rpm, noise ≤69 dB

• V38: 37.7 cm³/rev, max pressure 25 MPa, flow 68.0 L/min @1800rpm, noise ≤70 dB

• V50: 51.6 cm³/rev, max pressure 21 MPa, flow 93.0 L/min @1800rpm, noise ≤70 dB

• V70: 69.8 cm³/rev, max pressure 21 MPa, flow 126.0 L/min @1800rpm, noise ≤71 dB

VZ Series Displacement Size Reference:

• VZ50: 50.2 cm³/rev, max pressure 28 MPa, flow 90.4 L/min @1800rpm

• VZ63: 63.0 cm³/rev, max pressure 21 MPa, flow 113.4 L/min @1800rpm

• VZ80: 79.6 cm³/rev, max pressure 28 MPa, flow 143.3 L/min @1800rpm

• VZ100: 104.6 cm³/rev, max pressure 28 MPa, flow 188.3 L/min @1800rpm

• VZ130: 135.9 cm³/rev, max pressure 21 MPa, flow 244.6 L/min @1800rpm

Key Technical Advantages

1. SAJS Power-Match Control with Automatic Overload Protection
The V38SAJS-ARX-80S21 and V70SAJS-ARX-20 are both equipped with the SAJS Power-Match Control module. This control method automatically reduces pump displacement as load increases, maintaining pump input power within the motor’s available power range and effectively preventing motor overload — achieving automatic matching between hydraulic system power and prime mover output power.Power-match control is particularly suitable for injection molding machines, forging presses, and other industrial hydraulic systems requiring stable power output under variable load conditions.

2. A3RX Pressure Compensator Control with Remote Adjustment Capability
The V70A3RX-60RC employs A3 pressure compensator control (mechanically adjusted) with a pressure adjustment range of 3.5–21 MPa. The discharge pressure can be set to the desired value by turning the pressure adjustment screw on the PC valve: clockwise rotation increases pressure, counterclockwise rotation decreases pressure.The RC code indicates the model is equipped with a remote control system, enabling remote pressure adjustment via a pilot valve. The pressure adjustment range with a remote control system is the 4th pattern (3rd pattern for VZ130).

3. Swashplate Design with Low Noise Operation Across Full Pressure Range
The V series features a unique swashplate angle variation function as its core design. By increasing the rigidity of the swashplate structure and optimizing the housing geometry using state-of-the-art measurement and analysis technologies, low noise operation is achieved across the entire pressure range. The V series maintains noise levels between 68–71 dB(A), providing a more comfortable working environment for operators.

4. High Power Density with Compact Lightweight Design
The V series employs a cradle swash plate design, achieving high pressure in a compact and lightweight body, resulting in increased output per unit weight. The V38 achieves a maximum operating pressure of 25 MPa and a theoretical flow of 68 L/min at 37.7 cm³/rev; the V70 achieves a theoretical flow of 126 L/min at 69.8 cm³/rev, leading its displacement class in power density.

5. VZ Series High-Pressure High-Density Upgrade
The VZ series, as the high-pressure high-density extension of the V series, raises the rated pressure to 28 MPa (VZ50, VZ80, VZ100) with displacements spanning 50.2–135.9 cm³/rev. The VZ series employs a spherical valve plate and optimized hydraulic balance, achieving stable and highly efficient operation over a broad range of operating conditions. The spherical valve plate with superior abrasion resistance improves anti-contaminant characteristics, extending maintenance intervals.

6. Wide Hydraulic Fluid Compatibility
The V series supports multiple hydraulic fluid types: no designation for petroleum-based hydraulic fluid, W for water-glycol hydraulic fluid, and F for phosphate ester hydraulic fluid. Note that the VZ series is only acceptable for petroleum-based hydraulic fluids.This wide compatibility enables V series pumps to meet the fluid requirements of diverse industrial applications.

Application Areas

• Machine Tools: CNC machine hydraulic systems, hydraulic fixtures, precision grinder hydraulic power sources

• Forging Equipment: Hydraulic presses, stamping equipment main hydraulic pumps

• Plastic Molding Equipment: Injection molding machine clamp and injection hydraulic systems

• Tool Machinery: Various tool machine hydraulic drive systems

• Metallurgical Equipment: Rolling mill hydraulic systems, smelting equipment hydraulic power sources

• Marine & Offshore: Ship deck machinery hydraulic systems, marine winch hydraulic systems

• Large Hydraulic Equipment: VZ series suitable for large hydraulic presses, die-casting machines, ships, metallurgy, and other heavy-duty industrial applications

Expert Maintenance Tips

1. Hydraulic Fluid Cleanliness
The V series control spool operates with tight clearances and is sensitive to particulate contamination. System fluid cleanliness must meet ISO 4406 18/15 or better. Recommended fluids are ISO VG32 or VG46 anti-wear hydraulic oils (petroleum-based) with a viscosity range of 20–400 mm²/s and temperature range of 0–60°C. Install a 10 μm absolute-rated filter element at the pump inlet. Replace elements at 500 hours after first commissioning, then every 1,000 operating hours or 6 months, whichever comes first.

2. SAJS Power-Match Controller Commissioning
The power-match controllers of the V38SAJS-ARX-80S21 and V70SAJS-ARX-20 should be calibrated according to the motor’s power characteristics. During commissioning, first confirm the motor’s rated power and rated current, then set the power control curve start point. The power control setting must ensure that the system does not exceed the motor’s available power at maximum working pressure, preventing motor overload. Adjust only with the system at zero load. Rotate the adjustment screw slowly and verify stable pressure gauge readings before proceeding.

3. A3RX Pressure Compensator Setting and Remote Adjustment
The V70A3RX-60RC pressure compensator adjustment range is 3.5–21 MPa. Set the pressure 15–20 bar above the maximum working load pressure, never exceeding 21 MPa. Turn the adjustment screw clockwise to increase discharge pressure, counterclockwise to decrease it. Excessive loosening of the adjustment screw may cause oil leakage from the threaded portion or parts to spring out; do not loosen the screw beyond the pressure adjustment range.The RC remote control system pilot valve should be selected from models JR-G(T)02, JRP-G02, or CR-G02P.

4. Case Drain Line Requirements
The case drain line must be installed independently, ensuring pressure within the pump housing is maintained at a normal pressure of less than 0.1 MPa and surge pressure of less than 0.5 MPa. The pipe end must be submerged in oil to prevent air ingestion. Never tie the drain line into the main system return line. For “shaft-up” vertical mounting positions, filling and air bleeding must be performed completely.

5. Pre-Start Priming and Air Bleeding
Before first start, fill the pump housing with clean hydraulic fluid through the case drain port. After installation, turn the drive shaft by hand several revolutions to confirm free rotation without binding. Position the control at neutral (zero displacement) and run at low speed for 5–10 minutes. Verify continuous bubble-free flow from the case drain. Only then apply load.

6. Hydraulic Fluid Replacement Interval
Replace hydraulic fluid every 1,000–3,000 operating hours or every six months, whichever comes first. 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 60°C. The VZ series is only acceptable for petroleum-based hydraulic fluids; note fluid compatibility when selecting.