Piston pump
HENGYUHANG Axial Piston ston fixed pump HYH4FO
HENGYUHANG HYH4FO Series is a heavy-duty swashplate axial piston fixed displacement pump engineered for open-circuit hydrostatic drives, delivering high overall efficiency, superior power density, low operating noise, and continuous fatigue-resistant 350/400 bar performance with multi-pump through-drive capability across mobile and stationary equipment.
| Applications
Designed for primary open-circuit hydraulic power supplies in mobile construction machinery, excavators, wheeled loaders, mobile cranes, concrete mixer trucks, mining vehicles, and stationary industrial applications such as metal forming presses, marine winches, and centralized hydraulic power units requiring robust fixed displacement flow, compact physical dimensions, and auxiliary through-drive compounding.
| Key Technical Specifications
Product Model: HYH4FO Series (Sizes 22, 28, 71, 125, 180, 250, 500)
Brand Replacement: Bosch Rexroth A4FO Series (Sizes 22, 28, 71, 125, 180, 250, 500; open circuit), OEM or as requested.
Displacement: 22.0, 28.0, 71.0, 125.0, 180.0, 250.0, 500.0 cm³/rev (7 frame sizes)
Rotation Direction: Clockwise (R) or Counter-clockwise (L), viewed from shaft end
Speed Range: Nominal rating n nom 1,320–3,600 rpm (high-speed H-versions up to 1,500–1,900 rpm; limiting speed n max up to 1,600–4,500 rpm with boosted inlet)
Peak Pressure: Nominal pressure p nom = 400 bar / Maximum peak pressure p max = 450 bar (Sizes 22, 28); Nominal pressure p nom = 350 bar / Maximum peak pressure p max = 400 bar (Sizes 71 to 500)
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| Overview of HENGYUHANG HYH4FO Series Hydraulic Pumps
The HENGYUHANG HYH4FO Series is an open-circuit, swashplate-design axial piston fixed displacement pump. Built to provide an exact, 1:1 seamless drop-in replacement for the global Bosch Rexroth A4FO series (covering Series 32 for Sizes 22 and 28, Series 10 for Size 71, and Series 30 for Sizes 125, 180, 250, and 500), this pump converts mechanical drive torque into high-pressure fluid power with outstanding mechanical-hydraulic and volumetric efficiency.
Flow delivery is directly proportional to drive speed and geometric displacement. Featuring optimized housing dimensions tailored for constrained machine spaces, heavy-duty spherical cylinder kinematics, superior self-priming suction characteristics, and low fluid-borne noise generation, the HYH4FO operates continuously at 350 bar (Sizes 71–500) or 400 bar (Sizes 22–28) with transient peak withstand ratings up to 450 bar. Equipped with standardized SAE J744 2-bolt flanges or ISO 3019 4-bolt/8-bolt mountings, precision DIN 5480 splined shafts, ANSI B92.1a splined shafts, DIN 6885 keyed parallel drive shafts, SAE J518 code 62 high-pressure ports, and modular auxiliary through-drives for compounding secondary pumps, the HYH4FO delivers zero-modification field replacement, extended bearing service life, and unmatched operating reliability.
| Dimension of HENGYUHANG HYH4FO Series Hydraulic Pumps
| Mechanical Installation Interface Specifications
| Frame Size Band | Mounting Flange Standard | Drive Shaft (Splined ANSI / DIN) | Drive Shaft (Parallel Keyed DIN 6885) | Working Pressure Port B / A (SAE J518) | Suction Port S (SAE J518) | Case Drain Ports T / T1 / T2 (DIN 3852) |
|---|---|---|---|---|---|---|
| HYH4FO22 / 28 | SAE J744 2-hole 101-2 (B) Spigot Ø101.6 mm | Splined shaft ANSI B92.1a: 7/8 in 13T 16/32DP (Shaft S) | — | 3/4 in (Metric thread M10×1.5, 17 deep; 450 bar peak) | 1 1/2 in (Metric thread M12×1.75, 18 deep; 35 bar peak) | Drain T1 / T2: M18×1.5 (12 deep); Measuring X3: M14×1.5 |
| HYH4FO71 | ISO 3019-2 4-hole Spigot Ø140 mm (h8) | Splined shaft DIN 5480: W40×2×18×9g (Shaft Z) | Parallel keyed DIN 6885: AS12×8×68 (Shaft P) | B & B1: 1 in (Metric thread M12×1.75, 17 deep; 400 bar peak) | 2 in (Metric thread M12×1.75, 20 deep; 30 bar peak) | Drain T & Air bleed R(L): M27×2 (16 deep); Measuring MB/MS: M14×1.5 |
| HYH4FO125 | ISO 3019-2 4-hole Spigot Ø160 mm (h8) | Splined shaft DIN 5480: W50×2×24×9g (Shaft Z) | Parallel keyed DIN 6885: AS14×9×80 (Shaft P) | B & B1: 1 1/4 in (Metric thread M14×2, 19 deep; 400 bar peak) | 2 1/2 in (Metric thread M12×1.75, 17 deep) | Drain T & Air bleed R(L): M33×2 (18 deep); Flushing U & MB/MS: M14×1.5 |
| HYH4FO180 | ISO 3019-2 4-hole Spigot Ø160 mm (h8) | Splined shaft DIN 5480: W50×2×24×9g (Shaft Z) | Parallel keyed DIN 6885: AS14×9×80 (Shaft P) | B & B1: 1 1/4 in (Metric thread M14×2, 19 deep; 400 bar peak) | 3 in (Metric thread M16×2, 24 deep) | Drain T & Air bleed R(L): M33×2 (18 deep); Flushing U & MB/MS: M14×1.5 |
| HYH4FO250 | ISO 3019-2 4-hole Spigot Ø224 mm (h8) | Splined shaft DIN 5480: W60×2×28×9g (Shaft Z) | Parallel keyed DIN 6885: AS18×11×100 (Shaft P) | B & B1: 1 1/2 in (Metric thread M16×2, 24 deep; 400 bar peak) | 3 in (Metric thread M16×2, 24 deep) | Drain T & Air bleed R(L): M42×2 (20 deep); Flushing U & MB/MS: M14×1.5 |
| HYH4FO500 | ISO 3019-2 8-hole Spigot Ø315 mm (h8) | Splined shaft DIN 5480: W80×3×25×9g (Shaft Z) | Parallel keyed DIN 6885: AS22×14×125 (Shaft P) | B & B1: 2 in (Metric thread M20×2.5, 24 deep; 400 bar peak) | 5 in (Metric thread M16×2, 23 deep) | Drain T & Air bleed R(L): M48×2 (22 deep); Flushing U & MB/MS: M18×1.5 |
| Notes on Working Ports & Orientation
Port Execution 12: SAE working port and suction port at side, diametrically opposite (Sizes 22 and 28).
Port Execution 25: SAE working port B and suction port S at side, offset by 90°; second pressure port B1 located diametrically opposite to port B (Sizes 71 to 500, plugged with high-pressure flange plate on delivery).
| Pump Installation Specifications
| Complete Ordering Code Structure
HYH4F−[Fluid]−O−[Size]/[Series]−[Rotation][Seals][Shaft][Flange][Working Port]−[Through Drive]
| Position | Code Segment | Available Designations & Options | Technical Description & Functional Purpose |
|---|---|---|---|
| 01 | Hydraulic Fluid | Blank / E- / H- | Blank: Mineral oil and HFD; E-: HFA, HFB, HFC fluids (Sizes 71 to 500); H-: High-speed execution (Sizes 250, 500) |
| 02 | Axial Piston Unit | HYH4F / A4F | Swashplate design, fixed displacement |
| 03 | Operating Mode | O | Pump, open-circuit hydrostatic drive |
| 04 | Geometric Frame Size | 022, 028, 071, 125, 180, 250, 500 | Rated displacement in cm³/rev (22, 28, 71, 125, 180, 250, 500) |
| 05 | Series / Index | 32, 10, 30 | 32: Sizes 22 and 28; 10: Size 71; 30: Sizes 125, 180, 250, 500 |
| 06 | Direction of Rotation | R, L | Clockwise (R) or Counter-clockwise (L), viewed facing drive shaft end |
| 07 | Sealing System | N, P, V | N: NBR with FKM shaft seal (Sizes 22, 28); P: NBR seals (Sizes 71 to 500); V: Full FKM seals (Sizes 71 to 500) |
| 08 | Drive Shaft Type | S, Z, P | S: Splined shaft ANSI B92.1a (Sizes 22, 28); Z: Splined shaft DIN 5480; P: Parallel keyed shaft DIN 6885 |
| 09 | Mounting Flange | C, B, H | C: SAE J744 2-hole flange; B: ISO 3019-2 4-hole flange; H: ISO 3019-2 8-hole flange (Size 500) |
| 10 | Working Line Ports | 12, 25 | 12: Ports opposite at side (Sizes 22, 28); 25: Ports offset by 90° with second pressure port B1 (Sizes 71–500) |
| 11 | Through-Drive Option | N00 / K.. / U.. | N00: Without through drive; K..: Direct through drive for tandem pumps; U..: Universal through-drive hub |
| Reading Your Replacement Code
| Rexroth OEM Model Code | HENGYUHANG Drop-In Code | Displacement | Frame / Rotation | Shaft & Flange Specification | Porting & Through Drive |
|---|---|---|---|---|---|
| A4FO28/32R-NSC12N00 | HYH4FO28/32R-NSC12N00 | 28.0 cm³/rev | Series 32, Clockwise | ANSI 7/8" 13T spline, SAE 2-bolt Ø101.6 flange | Side opposite ports, without through drive |
| A4FO71/10R-PZB25N00 | HYH4FO71/10R-PZB25N00 | 71.0 cm³/rev | Series 10, Clockwise | DIN 5480 W40 spline, ISO 4-bolt Ø140 flange | 90° offset ports + B1 port, no through drive |
| A4FO125/30R-PPB25N00 | HYH4FO125/30R-PPB25N00 | 125.0 cm³/rev | Series 30, Clockwise | DIN 6885 AS14 keyed shaft, ISO 4-bolt Ø160 flange | 90° offset ports + B1 port, no through drive |
| A4FO180/30R-VZB25K01 | HYH4FO180/30R-VZB25K01 | 180.0 cm³/rev | Series 30, Clockwise | DIN 5480 W50 spline, ISO 4-bolt Ø160 flange | SAE A through drive for secondary pump |
| A4FO250/30R-VZB25N00 | HYH4FO250/30R-VZB25N00 | 250.0 cm³/rev | Series 30, Clockwise | DIN 5480 W60 spline, ISO 4-bolt Ø224 flange | 90° offset ports + B1 port, no through drive |
| A4FO500/30R-VZH25N00 | HYH4FO500/30R-VZH25N00 | 500.0 cm³/rev | Series 30, Clockwise | DIN 5480 W80 spline, ISO 8-bolt Ø315 flange | 90° offset ports + B1 port, no through drive |
Technical Specifications of HENGYUHANG HYH4FO Series (Sizes 22–500/H)
4.1 Frame Size Performance Matrix (Data at pₐᵦₛ=1 bar at suction port S, mineral oil ρ=0.88 kg/L)
| Performance Parameter | Unit | HYH4FO22 | HYH4FO28 | HYH4FO71 | HYH4FO125 | HYH4FO180 | HYH4FO250 (/H) | HYH4FO500 (/H) |
|---|---|---|---|---|---|---|---|---|
| Displacement (Vg) | cm³/rev | 22.0 | 28.0 | 71.0 | 125.0 | 180.0 | 250.0 | 500.0 |
| Max Nominal Speed (nₙₒₘ) | rpm | 3,600 | 3,000 | 2,200 | 1,800 | 1,800 | 1,500 / 1,900* | 1,320 / 1,500* |
| Limiting Speed (nₘₐₓ) | rpm | 4,500 | 3,750 | 2,700 | 2,200 | 2,100 | 1,800 / 2,100* | 1,600 / 1,800* |
| Max Continuous Flow Rate (qV at nₙₒₘ) | L/min | 79 | 84 | 156 | 225 | 324 | 375 / 475* | 660 / 750* |
| Drive Power at Continuous Rated Pressure | kW | 53 (400 bar) | 56 (400 bar) | 91 (350 bar) | 131 (350 bar) | 189 (350 bar) | 219 / 277* (350 bar) | 385 / 438* (350 bar) |
| Drive Torque at Continuous Rated Pressure | Nm | 140 (400 bar) | 178 (400 bar) | 396 (350 bar) | 696 (350 bar) | 1,003 (350 bar) | 1,393 (350 bar) | 2,785 (350 bar) |
| Drive Shaft Torsional Stiffness (c, Splined) | kNm/rad | 29.9 (Shaft S) | 29.9 (Shaft S) | 146 (Shaft Z) | 263 (Shaft Z) | 332 (Shaft Z) | 543 (Shaft Z) | 1,136 (Shaft Z) |
| Drive Shaft Torsional Stiffness (c, Keyed) | kNm/rad | — | — | 146 (Shaft P) | 260 (Shaft P) | 328 (Shaft P) | 527 (Shaft P) | 1,145 (Shaft P) |
| Moment of Inertia for Rotary Group (J_GR) | kg·m² | 0.0017 | 0.0017 | 0.0121 | 0.0300 | 0.0550 | 0.0959 | 0.3325 |
| Max Angular Acceleration (α) | rad/s² | 38,000 | 38,000 | 20,000 | 13,000 | 10,000 | 8,000 | 4,800 |
| Housing Case Volume | L | 0.30 | 0.30 | 2.00 | 3.00 | 4.00 | 7.00 | 11.00 |
| Dry Weight (approx.) | kg | 13.5 | 13.5 | 34.0 | 61.0 | 76.0 | 120.0 | 220.0 |
*Values with /H denote the high-speed execution.
4.2 Operating Pressure Boundaries
| Size Range | Nominal Pressure pₙₒₘ | Maximum Peak Pressure pₘₐₓ | Single Operating Period | Total Operating Life Under pₘₐₓ |
|---|---|---|---|---|
| Sizes 22 and 28 | 400 bar absolute | 450 bar absolute | ≤1 s | 300 hours |
| Sizes 71 to 500 | 350 bar absolute | 400 bar absolute | ≤1 s | 300 hours |
System Pressure & Suction Thresholds:
Minimum Pressure on High-Pressure Port (Sizes 22, 28): pₘᵢₙ≥25 bar absolute (required to prevent rotary group separation).
Rate of Pressure Change (RAₘₐₓ): Up to 16,000 bar/s permissible across all frame sizes without pressure relief valve.
Suction Port Pressure (pₛ at Port S): Minimum pₛₘᵢₙ≥0.8 bar absolute; Maximum continuous suction pressure pₛₘₐₓ=2 bar absolute (Sizes 22, 28) and pₛₘₐₓ=30 bar absolute (Sizes 71 to 500).
Permissible Housing Case Pressure: Momentary pressure peaks (t<0.1 s) up to 10 bar permitted; continuous case pressure must equal or slightly exceed ambient pressure.
4.3 Hydraulic Fluid & Temperature Operational Limits
| Fluid Characteristic | Permissible Value | Operational Note |
|---|---|---|
| Recommended Fluid Media | Mineral oil (HL, HLP to DIN 51524) | High-grade anti-wear hydraulic oil |
| Optimum Operating Viscosity (νₒₚₜ) | 16 to 36 mm²/s | Optimal balance of volumetric and mechanical efficiency |
| Continuous Operating Viscosity | 10 to 400 mm²/s | Normal operating temperature range |
| Minimum Viscosity (νₘᵢₙ) | 10 mm²/s (Sizes 22, 28) / 7 mm²/s (Sizes 71–500) | Short-term limit (t<3 min) at elevated localized drain port temperature |
| Maximum Viscosity at Cold Start (νₘₐₓ) | 1,600 mm²/s (Sizes 22, 28) / 1,000 mm²/s (Sizes 71–500) | Cold start (p≤50 bar, n≤1,000 rpm, θ_St≥−40 ∘C, warm-up period ≤3 min) |
| Permissible Fluid Temperature Range | −25 ∘C to +90 ∘C (FKM seal up to +115 ∘C) | Standard FKM dynamic shaft seal; NBR seal required for cold starts down to −40 ∘C |
| Cleanliness Class | ISO 4406 Class 20/18/15 | At very high fluid temperatures (+90 ∘C to +115 ∘C), maintain Class 19/17/14 |
| Alternative Fluids | HFA, HFB, HFC (Sizes 71 to 500 only with E- code) | Synthetic HFDR/HFDU; observe operational limits in RE 90222 and RE 90223 |
| Prohibited Fluids for Sizes 22 & 28 | HFA, HFB, HFC | Water-based hydraulic fluids strictly prohibited for Sizes 22 and 28 |
Product Advantages
Heavy-Duty Swashplate Axial Piston Architecture
Employs a rigid swashplate assembly with hardened spherical piston shoes and a bi-metal valve plate for minimal hydrodynamic friction and reliable continuous open-loop delivery.
Continuous 350 / 400 Bar Pressure Rating
Engineered with a robust, fatigue-proof housing capable of handling 350 bar (Sizes 71–500) and 400 bar (Sizes 22–28) continuous working pressure, with transient peak ratings up to 450 bar.
Outstanding Power-to-Weight Ratio
Extremely compact envelope delivers up to 189 kW (Size 180), 277 kW (Size 250/H), and 438 kW (Size 500/H) continuous power, optimizing installation density in mobile chassis and power packs.
Superior Suction Capabilities & Low Operating Noise
Advanced fluid port fluidics and optimized cylinder porting ensure high self-priming filling speeds, low fluid-borne noise generation, and smooth pulsation damping.
Full-Torque Modular Through-Drive Capability
Equipped with robust secondary through-drives (SAE A, B, metric ISO 3019-2, and DIN 5480 splined hubs), permitting 100% torque through-coupling for secondary gear or piston pumps.
Precision 1:1 OEM Drop-In Compatibility
Exact adherence to Bosch Rexroth A4FO mounting flange geometry, shaft splines, key dimensions, and SAE J518 port schedules enables seamless, zero-modification field replacements.
| 6. Interchangeability & Cross Reference
6.1 Direct Replacement Matrix: Bosch Rexroth A4FO to HENGYUHANG HYH4FO
| Rexroth OEM Model | Displacement | Mounting Flange Standard | Drive Shaft Specification | Working Port Connection | HENGYUHANG Direct Match |
|---|---|---|---|---|---|
| A4FO22 | 22.0 cm³/rev | SAE J744 2-Hole 101-2 (B) Ø101.6 mm | Splined ANSI B92.1a 7/8 in 13T (S) | SAE 3/4" Port B / 1 1/2" Port S (Code 12) | HYH4FO22 |
| A4FO28 | 28.0 cm³/rev | SAE J744 2-Hole 101-2 (B) Ø101.6 mm | Splined ANSI B92.1a 7/8 in 13T (S) | SAE 3/4" Port B / 1 1/2" Port S (Code 12) | HYH4FO28 |
| A4FO71 | 71.0 cm³/rev | ISO 3019-2 4-Hole Spigot Ø140 mm | DIN 5480 W40 (Z) / Keyed AS12 (P) | SAE 1" Ports B & B1 / 2" Port S (Code 25) | HYH4FO71 |
| A4FO125 | 125.0 cm³/rev | ISO 3019-2 4-Hole Spigot Ø160 mm | DIN 5480 W50 (Z) / Keyed AS14 (P) | SAE 1 1/4" Ports B & B1 / 2 1/2" Port S (Code 25) | HYH4FO125 |
| A4FO180 | 180.0 cm³/rev | ISO 3019-2 4-Hole Spigot Ø160 mm | DIN 5480 W50 (Z) / Keyed AS14 (P) | SAE 1 1/4" Ports B & B1 / 3" Port S (Code 25) | HYH4FO180 |
| A4FO250 | 250.0 cm³/rev | ISO 3019-2 4-Hole Spigot Ø224 mm | DIN 5480 W60 (Z) / Keyed AS18 (P) | SAE 1 1/2" Ports B & B1 / 3" Port S (Code 25) | HYH4FO250 |
| A4FO500 | 500.0 cm³/rev | ISO 3019-2 8-Hole Spigot Ø315 mm | DIN 5480 W80 (Z) / Keyed AS22 (P) | SAE 2" Ports B & B1 / 5" Port S (Code 25) | HYH4FO500 |
6.2 Modular Through-Drive Attachment Cross Reference
| Through Drive Code | Secondary Flange Type | Secondary Drive Hub Coupling | Typical Compound Pump Attached |
|---|---|---|---|
| K01 | SAE J744 82-2 (A) 2-Hole | Splined hub SAE J744 5/8 in 9T (16-4) | Auxiliary gear pump / pilot pressure pump |
| K02 / K68 | SAE J744 101-2 (B) 2-Hole | Splined hub SAE J744 7/8 in 13T (22-4) | Medium auxiliary gear pump or HYH4FO28 |
| KB2 / KB3 | ISO 3019-2 2-Hole 80 / 100 mm | Splined hub SAE 3/4 in / 7/8 in | Standard European auxiliary gear pump |
| KB4 / KB5 | ISO 3019-2 2-Hole 100 / 125 mm | Splined hub SAE 1 in / 1 1/4 in | High-flow steering / cooling gear pump |
| K31 | ISO 3019-2 4-Hole 125 mm | Splined hub DIN 5480 W32×2×14×9g | Tandem piston pump (e.g. HYH10VSO28/45) |
| K33 | ISO 3019-2 4-Hole 140 mm | Splined hub DIN 5480 W40×2×18×9g | Tandem piston pump (e.g. HYH4FO71 / HYH10VSO71) |
| K34 | ISO 3019-2 4-Hole 160 mm | Splined hub DIN 5480 W50×2×24×9g | High-flow tandem piston pump (HYH4FO125/180) |
| K35 | ISO 3019-2 4-Hole 224 mm | Splined hub DIN 5480 W60×2×28×9g | Heavy-duty tandem piston pump (HYH4FO250) |
| 7. Brand Replacement
Bosch Rexroth (Primary 1:1 direct interchangeability for A4FO Series open-circuit fixed displacement pumps)
Parker Hannifin, Danfoss, Eaton, and Kawasaki open-circuit fixed axial piston pumps engineered upon request
| 8. Applications
Excavators and Mobile Earthmoving Equipment: Auxiliary hydraulic pump driving cooling fan motors, hydraulic steering units, and pilot valve circuits.
Concrete Mixer Trucks and Heavy Haulers: Primary or auxiliary open-loop pump powering water wash-down systems, drum auxiliary positioning, and chute jacks.
Mobile Cranes and Drilling Rigs: High-pressure power supply for boom telescoping, outrigger cylinders, rotary drive assist, and track tensioners.
Heavy Industrial Hydraulic Presses: Pre-fill and rapid-traverse pressure feeds for metal forming, stamping, punching, and briquetting presses.
Marine and Offshore Winch Systems: Reliable high-pressure fluid feed for anchor handling, deck cranes, and offshore mooring winches.
Centralized Hydraulic Power Packs: Compact primary fluid supply in industrial power stations requiring continuous duty and secondary pump through-coupling.
| 9. Packaging & Shipping
| Packaging Layer | Specification & Protection Material | Safety Standard |
|---|---|---|
| Inner Protection | Corrosion-inhibiting VCI plastic wrap, desiccants, and heavy-duty port thread plugs | Prevents moisture, atmospheric corrosion, and debris contamination |
| Shock Cushioning | Custom-molded high-density expanded polyethylene (EPE) foam enclosure | Absorbs severe multi-axis transit impacts and protects shaft extensions |
| Outer Enclosure | ISPM-15 export-certified solid fumigation-free engineered wooden crate | Structural reinforcement for global ocean, air, and multimodal handling |
| Logistics Options | Express Courier (DHL, FedEx, UPS), Air Freight, LCL/FCL Ocean Cargo, DDP door-to-door | Dispatch in 48–72 hours for standard configurations; tailored tracking provided |
| 10. Why Choose Hengyuhang?
Direct Factory Precision Manufacturing & CNC Excellence: State-of-the-art multi-axis CNC machining centers, precision spherical grinding equipment, and sub-micron gear and bearing fitment (Ra < 0.2 μm) guarantee superior rotary group alignment and low internal leakage.
100% Full-Cycle Multi-Parameter Factory Inspection: Every HYH4FO pump undergoes automated test-bench trials verifying volumetric efficiency (> 94%), continuous and peak pressure hold at 350/400/450 bar, internal case leakage limits, response hysteresis, and vibration/noise spectra prior to dispatch.
Seamless 1:1 OEM Drop-In Interchangeability: Engineered to match European DIN, ISO 3019-2, and SAE standards down to the millimeter, allowing immediate replacement of Bosch Rexroth A4FO units with zero pipe rework or bracket modification.
Flexible Engineering Customization & Rapid Prototyping: In-house hydraulic engineering team provides tailored control-valve calibrations, special shaft profiles, auxiliary flushing ports, and rapid prototype turnarounds with minimal MOQ requirements.
Robust Supply Chain, Extensive Inventory & Fast Global Dispatch: Continuous inventory of finished cast bodies, bearing kits, rotary groups, and modular port plates enables standardized orders to ship globally within 48 to 72 hours.
12-Month Comprehensive Warranty & Lifetime Technical Support: All units are backed by an unconditional 12-month factory warranty, 24-hour drawing verification service, and lifetime engineering consultation from certified fluid power specialists.
HENGYUHANG Axial Piston Fixed Pump HYH4FO Series (Heavy-Duty Swashplate Open-Circuit Hydraulic Pump, 22.00~500.00 cm³/rev) is a high-pressure, fixed-displacement axial piston pump designed in swashplate architecture for hydrostatic drive systems in open-circuit mobile, stationary, and heavy industrial applications. Manufactured by Quanzhou Hengyuhang Power Technology Co., Ltd. as an engineered, direct-fit replacement line designed to match the benchmark performance, mounting dimensions, and hydraulic characteristics of the Rexroth A4FO Series (Series 10, 30, and 32), the HYH4FO Series features an optimized swashplate rotary group, one-piece steel-reinforced slipper pistons, heavy-duty drive shaft bearings, and high-rigidity ductile iron housings. Technical specifications, pressure tiers, and dimensional envelopes are engineered according to the official OEM benchmark baseline (RE 91455). Output flow is directly proportional to drive speed and displacement, delivering high power density, superior total efficiency (ηt > 91%~93%), optimized dimensions for tight installation spaces, low operating noise, excellent suction capability (pabs min = 0.8 bar), and standard 100% through-drive capability for auxiliary pump combinations. Spanning 7 standard geometric frame sizes—22, 28, 71, 125, 180, 250, and 500 cm³/rev (with optional high-speed H-versions for sizes 250 and 500)—the HYH4FO Series operates at nominal continuous pressures of 400 bar (450 bar peak) for sizes 22 and 28, and 350 bar (400 bar peak) for heavy industrial sizes 71 through 500. Fitted with standard SAE J744 2-bolt flanges (sizes 22/28) or ISO 3019-2 4-bolt / 8-bolt flanges (sizes 71~500), ANSI B92.1a or DIN 5480 splined shafts, and SAE J518 Code 62 high-pressure split-flange ports, the HYH4FO Series serves as an ultra-reliable, cost-effective drop-in replacement for mobile earthmoving, mining, metallurgy, drilling, and industrial hydraulic power units.
| Applications
The HYH4FO Series swashplate fixed displacement pump is built for heavy-duty, continuous-duty open-circuit hydraulic systems requiring high operating pressure, compact dimensions, and through-drive multi-pump capability:
Heavy Mobile Construction & Earthmoving Equipment: Auxiliary and implement hydraulic supply for heavy excavators, wheel loaders, trenchers, and surface road construction machinery.
Rotary Drilling Rigs & Foundation Equipment: Primary high-pressure pump powering kelly bar drives, rotary drill heads, casing oscillators, and mast winches.
Mining Machinery & Tunnel Boring Units: Continuous open-circuit hydraulic power for roadheaders, underground haulage vehicles, hydraulic roof bolters, and tunnel boring auxiliary circuits.
Heavy Industrial Forging, Stamping & Extrusion Presses: Continuous 350~400 bar primary power supply for metal forging presses, scrap balers, shearers, and powder compaction presses.
Marine Deck Cranes & Winch Systems: Powers high-torque hydrostatic drives for shipboard cranes, offshore anchor handling winches, capstans, and oceanographic reels.
Multi-Pump Power Units & Industrial Test Benches: Leverages full-torque through-drive configurations (SAE A, SAE B, and ISO flanges) to mount secondary auxiliary gear or piston pumps in tandem.
| Key Specifications Overview
| Parameter | Hengyuhang HYH4FO Series Engineering Specification (OEM Benchmark Standard) |
|---|---|
| Pump Classification | Axial Piston Fixed Displacement Pump in Swashplate Design for Open Circuits (HYH4FO Series) |
| OEM Interchange Reference | Direct dimensional, functional, and hydraulic drop-in replacement for Rexroth A4FO Series (Series 10, 30, 32) |
| Standard Displacement Range | 7 Primary Frame Sizes: 22, 28, 71, 125, 180, 250, 500 cm³/rev (plus 250/H and 500/H High-Speed Versions) |
| Nominal Continuous Pressure (pnom) | Sizes 22 & 28: 400 bar (40 MPa / 5,800 psi); Sizes 71 to 500: 350 bar (35 MPa / 5,075 psi) |
| Maximum Peak Operating Pressure (pmax) | Sizes 22 & 28: 450 bar (45 MPa / 6,525 psi); Sizes 71 to 500: 400 bar (40 MPa / 5,800 psi) |
| Minimum High-Pressure Holding (pmin) | Sizes 22 & 28: 25 bar absolute minimum pressure required on high-pressure side to prevent slipper liftoff |
| Permissible Rate of Pressure Change (RA max) | 16,000 bar/s maximum permissible rate of pressure build-up and reduction across entire pressure range |
| Rotational Speed Range (at pabs = 1 bar) | Nominal drive speeds from 1320 rpm (Size 500) up to 3600 rpm (Size 22); High-speed version up to 1900 rpm (Size 250/H) |
| Delivery Flow Characteristics | Constant fixed delivery flow directly proportional to drive rotational speed and geometric displacement |
| Permissible Suction Pressure (Port S) | pS min = 0.8 bar absolute minimum continuous inlet pressure; pS max = 2 bar (sizes 22/28) / 30 bar (sizes 71~500) |
| Case Drain Pressure Rating (Ports T / T1 / T2) | Case pressure must be ≥ ambient pressure; Momentary pressure peaks up to 10 bar (t < 0.1 s) permissible |
| Rotary Group & Piston Technology | Rigid swashplate design with spheroidal cast iron cylinder block, steel-backed valve plate, and hardened pistons |
| Bearing System & Flush Port Option | Heavy-duty preloaded tapered roller bearings; Sizes 71~500 feature Port U for external bearing flushing |
| Mounting Flange Standards | Sizes 22/28: SAE J744 101-2 (SAE B 2-bolt, Code C); Sizes 71~250: ISO 3019-2 4-bolt (Code B); Size 500: ISO 8-bolt (Code H) |
| Drive Shaft Configurations | Sizes 22/28: ANSI B92.1a 7/8 in splined shaft (Code S); Sizes 71~500: DIN 5480 splined (Code Z) or DIN 6885 keyed (Code P) |
| High-Pressure Working Ports (B / A / B1) | SAE J518 Code 62 high-pressure 4-bolt split flange ports (metric fastening threads DIN 13); Dual outlet B/B1 on sizes 71~500 |
| Suction Fluid Port (Port S) | SAE J518 Code 61 standard 4-bolt split flange suction port (metric fastening threads DIN 13) |
| Sealing Material System | Code V: Premium FKM fluoroelastomer (-25°C to +115°C); Code N/P: NBR nitrile rubber for low temperature (-40°C to +90°C) |
| Direction of Rotation | Clockwise (Code R) or Counter-Clockwise (Code L), viewed facing input drive shaft |
| Operating Viscosity Range | Optimum: νopt = 16 to 36 mm²/s; Minimum: νmin = 10 mm²/s (short-term, max +115°C); Maximum: νmax = 1000 mm²/s (cold start) |
| Fluid Cleanliness Standard | ISO 4406 Class 20/18/15 minimum (Class 19/17/14 required for high operating temperatures 90°C~115°C) |
| Through-Drive Capability | Standard rear through-drive shaft (Code K / U) for mounting secondary axial piston, vane, or gear pumps |
| Technical Performance Matrix Across Available Sizes
| Model Number (Hengyuhang Series) | Geometric Displacement Vg (cm³/rev) | Drive Speed (rpm) | Delivery Flow @ n_nom (L/min) | Input Power P (kW) | Drive Torque T (Nm) | Rotary Stiffness c (kNm/rad) | Case Fill (L) | Unit Mass (kg, approx) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal n_nom | Max. n_max | @ 350 bar | @ 400 bar | @ 350 bar | @ 400 bar | Shaft Z/S | Shaft P | |||||
| Compact High-Pressure Series (Series 32, 400 bar Nominal / 450 bar Peak) | ||||||||||||
| HYH4FO-22 | 22.00 | 3600 | 4500 | 79.0 | — | 53.0 | — | 140.0 | 29.9 (Shaft S) | — | 0.30 | 13.5 |
| HYH4FO-28 | 28.00 | 3000 | 3750 | 84.0 | — | 56.0 | — | 178.0 | 29.9 (Shaft S) | — | 0.30 | 13.5 |
| Industrial Medium & Heavy Series (Series 10 & 30, 350 bar Nominal / 400 bar Peak) | ||||||||||||
| HYH4FO-71 | 71.00 | 2200 | 2700 | 156.0 | 91.0 | — | 396.0 | — | 146.0 | 146.0 | 2.00 | 34.0 |
| HYH4FO-125 | 125.00 | 1800 | 2200 | 225.0 | 131.0 | — | 696.0 | — | 263.0 | 260.0 | 3.00 | 61.0 |
| HYH4FO-180 | 180.00 | 1800 | 2100 | 324.0 | 189.0 | — | 1003.0 | — | 332.0 | 328.0 | 4.00 | 76.0 |
| HYH4FO-250 | 250.00 | 1500 | 1800 | 375.0 | 219.0 | — | 1393.0 | — | 543.0 | 527.0 | 7.00 | 120.0 |
| HYH4FO-250/H | 250.00 | 1900 | 2100 | 475.0 | 277.0 | — | 1393.0 | — | 543.0 | 527.0 | 7.00 | 120.0 |
| HYH4FO-500 | 500.00 | 1320 | 1600 | 660.0 | 385.0 | — | 2785.0 | — | 1136.0 | 1145.0 | 11.00 | 220.0 |
| HYH4FO-500/H | 500.00 | 1500 | 1800 | 750.0 | 438.0 | — | 2785.0 | — | 1136.0 | 1145.0 | 11.00 | 220.0 |
| Mounting Flange, Shaft and Port Specifications Across Sizes
| Size Group | Mounting Flange Standards | Drive Shaft Options (ANSI / DIN) | Fluid Port Connections (Service, Suction & Drain) |
|---|---|---|---|
| HYH4FO-22 / 28 | SAE J744 101-2 (SAE B 2-bolt): Pilot Ø101.6 mm (+0/-0.05 mm); Bolt pitch 146 mm; 2 × Ø14.3 mm holes | Code S: Splined shaft ANSI B92.1a 7/8 in, 13T 16/32DP, 30° pressure angle, flat root side fit (usable ext. 41.3 mm) | Port B(A) Service: SAE J518 Code 62 3/4 in (450 bar, M10×1.5, 17 deep); Port S Suction: SAE J518 Code 61 1 1/2 in (35 bar, M12×1.75, 18 deep); Drain T1/T2: DIN 3852 M18×1.5 (12 deep); Gauge X3: M14×1.5 |
| HYH4FO-71 | ISO 3019-2 4-hole (Code B): Pilot Ø140 mm h8 (-0.040 mm); Pitch circle Ø180 mm; 4 × Ø18 mm through holes | Code Z: Spline DIN 5480 W40×2×18×9g (ext. 45 mm); Code P: Keyed DIN 6885 AS12×8×68 (shaft Ø40 k6, ext. 68 mm, M12×1.75 thread) | Port B Service: SAE J518 Code 62 1 in (400 bar, M12×1.75, 17 deep); 2nd Port B1: Code 62 1 in (opposite B, plugged); Port S Suction: Code 61 2 in (30 bar, M12×1.75, 20 deep); Drain T: DIN 3852 M27×2 (16 deep) |
| HYH4FO-125 | ISO 3019-2 4-hole (Code B): Pilot Ø160 mm h8 (-0.040 mm); Pitch circle Ø200 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W50×2×24×9g (ext. 54 mm); Code P: Keyed DIN 6885 AS14×9×80 (shaft Ø50 k6, ext. 80 mm, M16×2 thread) | Port B Service: SAE J518 Code 62 1 1/4 in (400 bar, M14×2, 19 deep); 2nd Port B1: Code 62 1 1/4 in (opposite B, plugged); Port S Suction: Code 61 2 1/2 in (30 bar, M12×1.75, 17 deep); Drain T: DIN 3852 M33×2 (18 deep); Flush U: M14×1.5 |
| HYH4FO-180 | ISO 3019-2 4-hole (Code B): Pilot Ø160 mm h8 (-0.040 mm); Pitch circle Ø200 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W50×2×24×9g (ext. 54 mm); Code P: Keyed DIN 6885 AS14×9×80 (shaft Ø50 k6, ext. 80 mm, M16×2 thread) | Port B Service: SAE J518 Code 62 1 1/4 in (400 bar, M14×2, 19 deep); 2nd Port B1: Code 62 1 1/4 in (opposite B, plugged); Port S Suction: Code 61 3 in (30 bar, M16×2, 24 deep); Drain T: DIN 3852 M33×2 (18 deep); Flush U: M14×1.5 |
| HYH4FO-250 | ISO 3019-2 4-hole (Code B): Pilot Ø224 mm h8 (-0.046 mm); Pitch circle Ø280 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W60×2×28×9g (ext. 70 mm); Code P: Keyed DIN 6885 AS18×11×100 (shaft Ø60 m6, ext. 100 mm, M20×2.5 thread) | Port B Service: SAE J518 Code 62 1 1/2 in (400 bar, M16×2, 24 deep); 2nd Port B1: Code 62 1 1/2 in (opposite B, plugged); Port S Suction: Code 61 3 in (30 bar, M16×2, 24 deep); Drain T: DIN 3852 M42×2 (20 deep); Flush U: M14×1.5 |
| HYH4FO-500 | ISO 3019-2 8-hole (Code H): Pilot Ø315 mm h8 (-0.050 mm); Pitch circle Ø360 mm; 8 × Ø22 mm through holes | Code Z: Spline DIN 5480 W80×3×25×9g (ext. 90 mm); Code P: Keyed DIN 6885 AS22×14×125 (shaft Ø80 m6, ext. 125 mm, M20×2.5 thread) | Port B Service: SAE J518 Code 62 2 in (400 bar, M20×2.5, 24 deep); 2nd Port B1: Code 62 2 in (opposite B, plugged); Port S Suction: Code 61 5 in (30 bar, M16×2, 23 deep); Drain T: DIN 3852 M48×2 (22 deep); Flush U: M18×1.5 |
| Through-Drive Options and Multi-Pump Combinations
| Through-Drive Code | Mounting Flange Standard | Internal Splined Coupling Hub | Typical 2nd Pump Attachment Compatibility |
|---|---|---|---|
| N00 | Without through drive | None (closed rear housing end) | Single pump standalone operation |
| K01 / U01 | SAE J744 82-2 (SAE A 2-bolt) | Spline ANSI B92.1a 5/8 in 9T 16/32DP | Mini external gear pumps, pilot auxiliary pumps (HYH-HGP, AZPF) |
| K02 / U02 | SAE J744 101-2 (SAE B 2-bolt) | Spline ANSI B92.1a 7/8 in 13T 16/32DP | Medium gear pumps, secondary HYH4FO-22/28, HYH10VSO-28 |
| KB2 / UB2 | ISO 3019-2 80, 2-hole | Spline SAE J744 3/4 in 11T 16/32DP | European standard small gear and piston pumps |
| KB3 / UB3 | ISO 3019-2 100, 2-hole | Spline SAE J744 7/8 in 13T 16/32DP | Medium European gear pumps, HYH10VSO-28/45 |
| KB4 / UB4 | ISO 3019-2 100, 2-hole | Spline SAE J744 1 in 15T 16/32DP | HYH10VSO-45, heavy-duty gear pumps |
| K31 / U31 | ISO 3019-2 125, 4-hole | Spline DIN 5480 W32×2×14×9g | HYH10VSO-45, medium axial piston units |
| K33 / U33 | ISO 3019-2 140, 4-hole | Spline DIN 5480 W40×2×18×9g | Secondary HYH4FO-71, HYH10VSO-71 |
| K34 / U34 | ISO 3019-2 160, 4-hole | Spline DIN 5480 W50×2×24×9g | Secondary HYH4FO-125/180, HYH10VSO-100/140 |
| K99 / U99 | Universal mounting pad with cover | Shaft end prepared without intermediate hub | Reserved through-drive for future field retrofitting |
| Direct Interchangeability and OEM Replacement Matrix (Rexroth A4FO Series)
| Hengyuhang Series Model | OEM Original Rexroth Reference Model | Shaft & Flange Standard | Interchangeability Verification Status |
|---|---|---|---|
| HYH4FO-22 | A4FO 22 / 32R-NSC12N00 (or 32L-NSC12N00) | ANSI 7/8 in Spline, SAE B 2-Bolt | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-28 | A4FO 28 / 32R-NSC12N00 (or 32L-NSC12N00) | ANSI 7/8 in Spline, SAE B 2-Bolt | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-71 | A4FO 71 / 10R-PZB25N00 (or 10R-PPB25N00) | DIN 5480 W40, ISO 4-Bolt Ø140 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-125 | A4FO 125 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W50, ISO 4-Bolt Ø160 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-180 | A4FO 180 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W50, ISO 4-Bolt Ø160 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-250 | A4FO 250 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W60, ISO 4-Bolt Ø224 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-250/H | A4FO 250 / 30R-PZB25N00-H (High Speed) | DIN 5480 W60, ISO 4-Bolt Ø224 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-500 | A4FO 500 / 30R-PZH25N00 (or 30R-PPH25N00) | DIN 5480 W80, ISO 8-Bolt Ø315 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-500/H | A4FO 500 / 30R-PZH25N00-H (High Speed) | DIN 5480 W80, ISO 8-Bolt Ø315 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| Model Coding & Ordering Structure
| Code Field | Field Designation | Available Standard Codes | Technical Definition & Configuration Meaning |
|---|---|---|---|
| [01] Fluid | Hydraulic Fluid Compatibility | Standard (without code) / E- / H- | Standard: Mineral oil and HFD; Code E-: HFA/HFB/HFC water-based fluids; Code H-: High-speed version (Sizes 250 & 500) |
| [02] Unit Type | Axial Piston Pump Series | HYH4F | Swashplate design, fixed displacement axial piston machine |
| [03] Mode | Circuit Operation Mode | O | Open-circuit hydrostatic drive pump |
| [04] Frame Size | Geometric Displacement (cm³) | 022, 028, 071, 125, 180, 250, 500 | Nominal geometric displacement per revolution Vg in cm³/rev |
| [05] Series | Series & Design Index | 32 / 10 / 30 | Code 32: Series 3, Index 2 (Sizes 22/28); Code 10: Series 1, Index 0 (Size 71); Code 30: Series 3, Index 0 (Sizes 125~500) |
| [06] Rotation | Direction of Rotation | R / L | Code R: Clockwise rotation; Code L: Counter-Clockwise rotation, viewed facing drive shaft |
| [07] Seals | Sealing Material System | N / P / V | Code N: NBR nitrile rubber (Sizes 22/28); Code P: NBR with FKM shaft seal; Code V: Full FKM fluoroelastomer (-25°C to +115°C) |
| [08] Drive Shaft | Input Shaft Configuration | S / Z / P | Code S: ANSI B92.1a splined shaft (Sizes 22/28); Code Z: DIN 5480 splined shaft; Code P: DIN 6885 parallel keyed shaft |
| [09] Mounting Flange | Mounting Flange Style | C / B / H | Code C: SAE J744 2-bolt (Sizes 22/28); Code B: ISO 3019-2 4-bolt (Sizes 71~250); Code H: ISO 3019-2 8-bolt (Size 500) |
| [10] Working Ports | Service Port Configuration | 12 / 25 | Code 12: SAE pressure & suction opposite (Sizes 22/28); Code 25: SAE pressure & suction offset 90° with opposite plugged B1 |
| [11] Through Drive | Rear Through-Drive Attachment | N00 / K01~K43 / U01~U34 / K99 | Code N00: Without through drive; Code K/U: Standard auxiliary mounting flanges (SAE A, SAE B, ISO metric) |
| Technical Performance Matrix Across Available Sizes
| Model Number (Hengyuhang Series) | Geometric Displacement Vg (cm³/rev) | Drive Speed (rpm) | Delivery Flow @ n_nom (L/min) | Input Power P (kW) | Drive Torque T (Nm) | Rotary Stiffness c (kNm/rad) | Case Fill (L) | Unit Mass (kg, approx) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal n_nom | Max. n_max | @ 350 bar | @ 400 bar | @ 350 bar | @ 400 bar | Shaft Z/S | Shaft P | |||||
| Compact High-Pressure Series (Series 32, 400 bar Nominal / 450 bar Peak) | ||||||||||||
| HYH4FO-22 | 22.00 | 3600 | 4500 | 79.0 | — | 53.0 | — | 140.0 | 29.9 (Shaft S) | — | 0.30 | 13.5 |
| HYH4FO-28 | 28.00 | 3000 | 3750 | 84.0 | — | 56.0 | — | 178.0 | 29.9 (Shaft S) | — | 0.30 | 13.5 |
| Industrial Medium & Heavy Series (Series 10 & 30, 350 bar Nominal / 400 bar Peak) | ||||||||||||
| HYH4FO-71 | 71.00 | 2200 | 2700 | 156.0 | 91.0 | — | 396.0 | — | 146.0 | 146.0 | 2.00 | 34.0 |
| HYH4FO-125 | 125.00 | 1800 | 2200 | 225.0 | 131.0 | — | 696.0 | — | 263.0 | 260.0 | 3.00 | 61.0 |
| HYH4FO-180 | 180.00 | 1800 | 2100 | 324.0 | 189.0 | — | 1003.0 | — | 332.0 | 328.0 | 4.00 | 76.0 |
| HYH4FO-250 | 250.00 | 1500 | 1800 | 375.0 | 219.0 | — | 1393.0 | — | 543.0 | 527.0 | 7.00 | 120.0 |
| HYH4FO-250/H | 250.00 | 1900 | 2100 | 475.0 | 277.0 | — | 1393.0 | — | 543.0 | 527.0 | 7.00 | 120.0 |
| HYH4FO-500 | 500.00 | 1320 | 1600 | 660.0 | 385.0 | — | 2785.0 | — | 1136.0 | 1145.0 | 11.00 | 220.0 |
| HYH4FO-500/H | 500.00 | 1500 | 1800 | 750.0 | 438.0 | — | 2785.0 | — | 1136.0 | 1145.0 | 11.00 | 220.0 |
| Size Group | Mounting Flange Standards | Drive Shaft Options (ANSI / DIN) | Fluid Port Connections (Service, Suction & Drain) |
|---|---|---|---|
| HYH4FO-22 / 28 | SAE J744 101-2 (SAE B 2-bolt): Pilot Ø101.6 mm (+0/-0.05 mm); Bolt pitch 146 mm; 2 × Ø14.3 mm holes | Code S: Splined shaft ANSI B92.1a 7/8 in, 13T 16/32DP, 30° pressure angle, flat root side fit (usable ext. 41.3 mm) | Port B(A) Service: SAE J518 Code 62 3/4 in (450 bar, M10×1.5, 17 deep); Port S Suction: SAE J518 Code 61 1 1/2 in (35 bar, M12×1.75, 18 deep); Drain T1/T2: DIN 3852 M18×1.5 (12 deep); Gauge X3: M14×1.5 |
| HYH4FO-71 | ISO 3019-2 4-hole (Code B): Pilot Ø140 mm h8 (-0.040 mm); Pitch circle Ø180 mm; 4 × Ø18 mm through holes | Code Z: Spline DIN 5480 W40×2×18×9g (ext. 45 mm); Code P: Keyed DIN 6885 AS12×8×68 (shaft Ø40 k6, ext. 68 mm, M12×1.75 thread) | Port B Service: SAE J518 Code 62 1 in (400 bar, M12×1.75, 17 deep); 2nd Port B1: Code 62 1 in (opposite B, plugged); Port S Suction: Code 61 2 in (30 bar, M12×1.75, 20 deep); Drain T: DIN 3852 M27×2 (16 deep) |
| HYH4FO-125 | ISO 3019-2 4-hole (Code B): Pilot Ø160 mm h8 (-0.040 mm); Pitch circle Ø200 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W50×2×24×9g (ext. 54 mm); Code P: Keyed DIN 6885 AS14×9×80 (shaft Ø50 k6, ext. 80 mm, M16×2 thread) | Port B Service: SAE J518 Code 62 1 1/4 in (400 bar, M14×2, 19 deep); 2nd Port B1: Code 62 1 1/4 in (opposite B, plugged); Port S Suction: Code 61 2 1/2 in (30 bar, M12×1.75, 17 deep); Drain T: DIN 3852 M33×2 (18 deep); Flush U: M14×1.5 |
| HYH4FO-180 | ISO 3019-2 4-hole (Code B): Pilot Ø160 mm h8 (-0.040 mm); Pitch circle Ø200 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W50×2×24×9g (ext. 54 mm); Code P: Keyed DIN 6885 AS14×9×80 (shaft Ø50 k6, ext. 80 mm, M16×2 thread) | Port B Service: SAE J518 Code 62 1 1/4 in (400 bar, M14×2, 19 deep); 2nd Port B1: Code 62 1 1/4 in (opposite B, plugged); Port S Suction: Code 61 3 in (30 bar, M16×2, 24 deep); Drain T: DIN 3852 M33×2 (18 deep); Flush U: M14×1.5 |
| HYH4FO-250 | ISO 3019-2 4-hole (Code B): Pilot Ø224 mm h8 (-0.046 mm); Pitch circle Ø280 mm; 4 × Ø22 mm through holes | Code Z: Spline DIN 5480 W60×2×28×9g (ext. 70 mm); Code P: Keyed DIN 6885 AS18×11×100 (shaft Ø60 m6, ext. 100 mm, M20×2.5 thread) | Port B Service: SAE J518 Code 62 1 1/2 in (400 bar, M16×2, 24 deep); 2nd Port B1: Code 62 1 1/2 in (opposite B, plugged); Port S Suction: Code 61 3 in (30 bar, M16×2, 24 deep); Drain T: DIN 3852 M42×2 (20 deep); Flush U: M14×1.5 |
| HYH4FO-500 | ISO 3019-2 8-hole (Code H): Pilot Ø315 mm h8 (-0.050 mm); Pitch circle Ø360 mm; 8 × Ø22 mm through holes | Code Z: Spline DIN 5480 W80×3×25×9g (ext. 90 mm); Code P: Keyed DIN 6885 AS22×14×125 (shaft Ø80 m6, ext. 125 mm, M20×2.5 thread) | Port B Service: SAE J518 Code 62 2 in (400 bar, M20×2.5, 24 deep); 2nd Port B1: Code 62 2 in (opposite B, plugged); Port S Suction: Code 61 5 in (30 bar, M16×2, 23 deep); Drain T: DIN 3852 M48×2 (22 deep); Flush U: M18×1.5 |
| Hengyuhang Series Model | OEM Original Rexroth Reference Model | Shaft & Flange Standard | Interchangeability Verification Status |
|---|---|---|---|
| HYH4FO-22 | A4FO 22 / 32R-NSC12N00 (or 32L-NSC12N00) | ANSI 7/8 in Spline, SAE B 2-Bolt | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-28 | A4FO 28 / 32R-NSC12N00 (or 32L-NSC12N00) | ANSI 7/8 in Spline, SAE B 2-Bolt | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-71 | A4FO 71 / 10R-PZB25N00 (or 10R-PPB25N00) | DIN 5480 W40, ISO 4-Bolt Ø140 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-125 | A4FO 125 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W50, ISO 4-Bolt Ø160 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-180 | A4FO 180 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W50, ISO 4-Bolt Ø160 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-250 | A4FO 250 / 30R-PZB25N00 (or 30R-PPB25N00) | DIN 5480 W60, ISO 4-Bolt Ø224 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-250/H | A4FO 250 / 30R-PZB25N00-H (High Speed) | DIN 5480 W60, ISO 4-Bolt Ø224 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-500 | A4FO 500 / 30R-PZH25N00 (or 30R-PPH25N00) | DIN 5480 W80, ISO 8-Bolt Ø315 | 100% Direct Physical & Hydraulic Drop-in Replacement |
| HYH4FO-500/H | A4FO 500 / 30R-PZH25N00-H (High Speed) | DIN 5480 W80, ISO 8-Bolt Ø315 | 100% Direct Physical & Hydraulic Drop-in Replacement |
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