P31VFR-20-CC-21-J Tokyo Keiki Variable Piston Pump 31cc

Product Overview

The P31VFR-20-CC-21-J is a TOKYO KEIKI P**V Series swashplate-type variable displacement piston pump with a maximum displacement of 31 cm³/rev (14.7 GPM) and rated operating pressure of 21 MPa (3,050 psi), with peak pressure capability up to 25 MPa. This model features FR combined control (load sensing + pressure compensation), delivering on-demand flow and constant pressure holding for energy-efficient operation.

The P**V Series is engineered for low noise, high performance, and exceptional reliability, employing a swashplate variable mechanism that delivers fast response and high stability. The series covers displacements from 8 to 130 cm³/rev with multiple control options including electric direct control, pressure compensator control, and load sensing control, adapting to a wide range of industrial applications from machine tools to construction machinery.

The P31VFR-20-CC-21-J offers exceptional field interchangeability, enabling direct replacement with same-series P31V pumps without requiring installation or plumbing modifications. The FR combined control is particularly suited for small-to-medium hydraulic systems requiring precise pressure stability and energy-saving operation.

Every P31VFR-20-CC-21-J undergoes 100% simulated duty-cycle testing prior to shipment — covering pressure holding, flow output, control response, and internal leakage — ensuring reliable field performance from day one.

Technical Specifications

• Model: P31VFR-20-CC-21-J

• Brand: TOKYO KEIKI / TOKIMEC

• Series: P**V Series swashplate-type variable displacement piston pump

• Maximum Displacement: 31 cm³/rev (14.7 GPM)

• Rated Operating Pressure: 21 MPa (3,050 psi)

• Peak Pressure: 25 MPa (with high-pressure seal configuration)

• Speed Range: 600–1800 rpm

• Common Operating Speed: 1500 / 1800 rpm

• Control Type: FR combined control (F = load sensing + R = pressure compensation)

• Direction of Rotation: Right-hand (clockwise, viewed from shaft end)

• Mounting Flange: SAE B flange (interchangeable with A37/P31/IPH5)

• Shaft Type: φ25 keyed shaft

• Seals: NBR (Nitrile) standard

• Housing Material: High-strength cast iron

• Port Connections: Suction Rc1″, Pressure Rc3/4″

• Weight: Approx. 28 kg

• Noise Level: ≤ 68 dB(A)

• Fluid Compatibility: Mineral oil, water-glycol (F11 option)

• Operating Temperature Range: 30–90 ℃

• Volumetric Efficiency: ≥ 94% (typical)

Key Technical Advantages

1. Low Noise Design — Quiet Operation Across Full Pressure Range
The P31VFR-20-CC-21-J employs TOKYO KEIKI’s proprietary low-noise swashplate design, maintaining a noise level of ≤ 68 dB(A) across the full pressure range. This is achieved through optimized valve plate flow passages, precision piston kinematics, and housing damping structures — particularly suitable for machine tools, precision injection molding machines, and other indoor industrial environments with stringent acoustic requirements.

2. FR Combined Control — Integrated Load Sensing and Pressure Compensation
The FR control integrates both load sensing (F) and pressure compensation (R) functions. Load sensing precisely matches pump output flow to actual system demand, eliminating relief losses; pressure compensation automatically reduces displacement to only leakage flow when system pressure reaches the set point. Combined, these functions deliver significant energy savings under variable load conditions while reducing system oil temperature and extending fluid and component life.

3. Fast Response and Pressure Stability
The swashplate variable mechanism combined with precision-machined control spools gives the P31VFR-20-CC-21-J rapid dynamic response capability. Under sudden load changes, the pump completes displacement adjustment within milliseconds, maintaining stable system pressure. Typical volumetric efficiency ≥ 94% and total efficiency ≥ 87% place it among the leaders in its class.

4. High-Strength Cast Iron Housing with Modular Design
The high-strength cast iron housing delivers superior impact and deformation resistance, suitable for heavy-duty and vibration-prone industrial environments. The modular control cover design supports rapid replacement and upgrade of control modes without pump disassembly, significantly reducing downtime. The pump is compatible with standard hydraulic oil and water-glycol media (F11 configuration), demonstrating exceptional media adaptability.

5. Exceptional Field Interchangeability
The P31VFR-20-CC-21-J features an SAE B standard mounting flange, fully interchangeable with other P31V series models as well as A37/IPH5 specifications. The φ25 keyed shaft standard interface and Rc1″ suction / Rc3/4″ pressure ports ensure rapid drop-in replacement with original TOKYO KEIKI products, dramatically reducing equipment downtime.

Application Areas

• Small-to-Medium Injection Molding Machines: 50–200 ton class clamping and injection circuits, FR control enabling energy-saving operation

• Precision CNC Machine Tools: Machining centers, CNC lathes, hydraulic fixtures and turret hydraulic systems, leveraging low noise and high pressure stability

• Hydraulic Presses: 50–200 ton class stretching, powder forming, and precision pressing stations

• Servo Bending Machines: Synchronous control, high-pressure holding, low-noise hydraulic power source

• Construction Equipment: Small excavators, loaders, truck-mounted cranes hydraulic systems

• Marine Deck Machinery: Anchor winches and steering gear (small) hydraulic power sources

• Rubber Machinery: Small vulcanizing machines and plasticizing machines

• Test Equipment: Pressure testing machines and fatigue testing machines (low flow, high pressure)

The P31VFR-20-CC-21-J is ideally suited for small-to-medium power hydraulic systems requiring 21 MPa continuous working pressure and displacements in the 20–31 cm³/rev range — the ideal configuration for precision injection molding machines and CNC machine tool hydraulic power units.

Expert Maintenance Tips

1. Shaft Alignment and Coupling Requirements
Maintain concentricity between the pump shaft and drive shaft within 0.05 mm. Flexible couplings are strongly recommended to accommodate minor angular misalignment. The P31VFR-20-CC-21-J features an SAE B flange and φ25 keyed shaft — never strike the shaft end during installation to avoid damaging internal seals and bearings. Ensure proper sealing of Rc1″ suction and Rc3/4″ pressure port connections to prevent air ingress.

2. Pre-Start Priming Procedure
Before initial startup, the pump must be slowly filled through the case drain port with clean hydraulic oil to ensure adequate lubrication and sealing during startup. Start the pump in jog mode until the pump and piping are sufficiently filled and vented. After complete venting, run at low pressure for 5–10 minutes, check piping and component tightness, then gradually increase to rated pressure.

3. FR Combined Controller Adjustment and System Commissioning
The load sensing and pressure compensation settings of the FR controller must be coordinated. The pressure compensation setting should be at least 10–15 bar below the system relief valve setting. The load sensing pressure differential is typically 1.5–2.0 MPa (depending on the specific control cover configuration). Adjustment must be performed with the pump at full displacement and low operating pressure to avoid system pressure oscillation.

4. Fluid Cleanliness and Filtration
Fluid cleanliness of ISO 18/16/13 (NAS Class 8) or better is recommended. Use pressure line filters with a filtration ratio β10 ≥ 75 (per ISO 4572). Avoid suction filters, which increase suction resistance and cavitation risk; if essential, use with a vacuum switch monitor. Install a breather filter with filtration accuracy ≤10 μm on the reservoir and regularly check oil level and fluid condition.

5. Restart Procedure After Extended Shutdown
If the pump has been idle for more than 30 days, manually rotate the shaft several turns to verify free rotation before restarting. Check for abnormal leakage at the case drain port. After startup, operate at low pressure for 10–15 minutes until oil temperature reaches normal operating range before applying full load. When using water-glycol media, shorten oil change intervals and increase fluid sampling frequency due to reduced lubricity.