ZhongYi Gear Manufacturer (a member of ZhongYi Machinery) | China Precision Gear & Rack Factory Since 2003
China hydraulic gear pumps manufacturer
External hydraulic gear pumps, tandem dual-section units, and two-stage assemblies for agricultural tractors, forklifts, log splitters, and combine harvesters.
Source Factory
China Direct (2,800m² Plant)
Pressure Rating
Up to 25 MPa (250 bar)
Engineering DFM
< 24 Hours Turnaround
Testing Protocol
100% Bench Tested
China OEM factory manufacturing direct-fit replacement tractor hydraulic gear pumps for Ford, Fiat, Massey Ferguson, Deutz, and John Deere.
Product type
External gear hydraulic pump
Total entries
42
Brand families
8
Displacement range
5.0 to 33.0 ml/r (including 30/14 and 18/12 ml/r tandem units)
Product Matrix
Browse specialized replacement series, OEM interchange families, and application-specific hydraulic gear pumps. Each product line includes complete model tables, displacement, pressure ratings, and port dimensions.
China OEM factory manufacturing direct-fit replacement tractor hydraulic gear pumps for Ford, Fiat, Massey Ferguson, Deutz, and John Deere.
China direct factory supplying direct-fit replacement hydraulic gear pumps for Ford and New Holland agricultural tractors with OEM-matched ports.
China direct factory supplying replacement hydraulic gear pumps for Fiat and Hesston tractors with standard European 4-bolt flanges and tapered shafts.
China direct factory supplying direct-replacement hydraulic gear pumps for Massey Ferguson agricultural tractors (MF 135, 165, 240, 265, 390).
China direct manufacturer supplying high-pressure replacement hydraulic gear pumps for Deutz D-series, DX-series, and Agrotron tractors.
China direct OEM factory supplying replacement hydraulic gear pumps for Deutz-Fahr tractors and combine harvesters with 100% bench testing.
China direct factory supplying direct-fit replacement hydraulic gear pumps for John Deere utility tractors, loaders, and steering circuits.
China OEM factory manufacturing direct-fit replacement external gear pumps for Parker Commercial intermeshing series with cast-iron durability.
China direct manufacturer of replacement hydraulic gear pumps for Romanian UTB Universal 445, 550, and 650 agricultural tractors.
China OEM factory manufacturing high-pressure hydraulic gear pumps (up to 25 MPa) for 1-10 ton diesel, electric, and LPG forklifts.
China direct manufacturer of positive displacement diesel fuel transfer and lift pumps for forklift internal combustion engines.
China direct factory manufacturing high-performance two-stage hydraulic gear pumps (up to 28 MPa / 4000 PSI) for gas-powered log splitters.
China OEM factory supplying tandem dual-section hydraulic gear pumps for combine harvesters, headers, and grain unloading systems.
China precision manufacturer of internal crescent gear rotors, gerotor gear sets, and external hydraulic gear pump rotating components.
China OEM factory manufacturing direct-acting and pilot-operated pressure limiting relief valve cartridges for hydraulic gear pumps and power packs.
Manufacturing capability
As an established China hydraulic gear pump manufacturer and OEM factory in Zhejiang, ZhongYi supplies precision external gear pumps, tandem dual-displacement units, and two-stage assemblies for mobile machinery and industrial hydraulic power packs. Hydraulic gear pumps convert mechanical rotary power into pressurized hydraulic fluid to drive linear actuators, hydraulic motors, steering cylinders, and implement linkages. ZhongYi provides precision external gear pumps engineered for mobile machinery and industrial hydraulic power packs, covering single-section, tandem dual-displacement, and two-stage high/low pressure configurations. The range spans nominal displacements from 3.5 ml/r to 36.0 ml/r with working pressures up to 25.0 MPa (250 bar). Applications include agricultural tractor hydraulics (direct replacements for Ford, Fiat, Massey Ferguson, Deutz, Deutz-Fahr, John Deere, Parker, and UTB), heavy forklift mast lift and power steering circuits, two-stage log splitter rapid advance and high-tonnage splitting circuits, and combine harvester header drives. All units are manufactured from high-strength cast iron and aircraft-grade aluminum alloy housings with precision heat-treated gear pairs, offering clockwise (right-hand) and anti-clockwise (left-hand) rotation, multiple shaft configurations (splined, keyed, or tapered), and international port thread standards (UNF, metric fine, BSP, and NPT). We support custom OEM development and aftermarket reverse-engineering from physical samples or CAD drawings.
Product types & variants
The final product form is confirmed from the buyer drawing, mating component, assembly layout, operating conditions, and inspection requirements.
Direct-fit replacement gear pumps for Ford, Fiat, Massey Ferguson, Deutz, Deutz-Fahr, John Deere, Parker, and UTB tractors, featuring OEM-matching flanges, shafts, and ports.
High-pressure external gear pumps (rated 24.5 to 25.0 MPa with displacements 31.5 to 36.0 ml/r) engineered for heavy-duty mast lift and steering demands.
Dual-displacement tandem pumps that combine a high-flow low-pressure section for rapid ram extension with a low-flow high-pressure stage (up to 28 MPa) for log splitting.
Dual-section pumps on a single drive shaft (16/10 ml/r at 20 MPa) powering separate header and machine service hydraulic circuits.
Low-pressure positive displacement transfer pumps (14 ml/r at 2.0 MPa) for engine fuel delivery and priming systems.
Internal crescent gear pump rotors, gerotor gear sets, and external spur/helical pump gears for engine lubrication and hydraulic systems.
Direct-acting and pilot-operated pressure limiting valve cartridges and safety bypass valves for hydraulic pumps and lubrication circuits.
Selection & Metallurgy guidance
Selecting a replacement or OEM hydraulic gear pump requires verifying six core parameters before ordering. 1. Confirm nominal displacement in ml/r: displacement multiplied by input RPM determines pump output flow. 2. Verify maximum operating pressure against your system relief valve setting. 3. Confirm direction of rotation: inspect the drive shaft end to determine whether the pump turns Clockwise (Right) or Anti-Clockwise (Left). A pump driven backwards will create a vacuum at the outlet, fail to prime, and burn its internal seals within seconds. 4. Match port threads exactly: agricultural and industrial equipment mixes UNF, metric fine, BSP, and NPT ports; using the correct port thread avoids adapters that induce turbulence and leak paths. 5. Inspect drive shaft and mounting flange geometry: verify pilot diameter, bolt hole pitch circle, and whether the shaft is splined, keyed, or tapered. 6. For log splitters, ensure the two-stage unloading valve pressure transition matches the engine horsepower to prevent engine stalling under peak load.
Quality Control & Inspection Matrix
Overseas procurement teams require verifiable technical data, not unsupported claims. Every production batch at ZhongYi is inspected against approved CAD blueprints and international standards (DIN, AGMA, ISO).
Component-Specific Quality Focus:
All hydraulic gear pumps manufactured by ZhongYi undergo 100% computerized end-of-line bench testing prior to packaging and dispatch. Testing protocols verify: volumetric efficiency (≥93% at rated pressure), mechanical efficiency, maximum stall pressure, internal case drainage leakage, relief valve crack-pressure calibration, and shaft seal integrity. The manufacturing system operates under IATF 16949 / ISO 9001 certified quality management protocols. Critical housing dimensions, bore roundness, and gear pocket clearances are inspected on high-precision 3D coordinate measuring machines (CMM) to maintain micro-inch tolerances required for high-pressure fluid containment. Every batch is traceable by permanent laser engraving and backed by full factory test inspection reports.
Validates 3D spatial GD&T, bore concentricity, center distance, and geometric tolerances down to ±0.002 mm.
Inspects involute tooth profile error (fα), lead crowning (fβ), pitch cumulative error (Fp), and radial runout (Fr).
Verifies surface hardness (58–62 HRC), core toughness, and effective carburized / nitrided case depth gradient.
100% chemical composition verification of alloy steel forgings (20CrMnTi, 42CrMo, 18CrNiMo7-6, Stainless, POM).
We maintain strict incoming material spectroscopy, in-process CNC tooth coordinate monitoring, and 100% final pre-shipment dimensional inspection. All custom gear batches are backed by our full manufacturing warranty.
Application fit
Match the gear type with real machinery conditions, operating environment, load, speed, and replacement requirements.
Discover how this gear category meets extreme torque, low backlash, quiet operation, and weather-resistance demands in primary industry sectors:
High-torque, impact-resistant gears, girth rings, and planetary drive sets engineered for excavators, cranes, drilling rigs, and heavy mining crushers.
Low-backlash, ultra-precise fine-pitch gears, ground helical racks, and planetary gearheads for robotics, AGV wheel drives, and high-speed motion axes.
High-torque bevel gears, spur gears, and splined drive shafts for tractors, harvesters, rotary tillers, and agricultural PTO gearboxes.
Technical FAQ
These answers support early engineering and procurement review. Final dimensions, materials, tolerances, and process requirements are confirmed against the approved drawing file.
ZhongYi operates an integrated gear and hydraulic manufacturing plant in Zhejiang, China. Every pump undergoes 100% computerized bench testing for volumetric efficiency and pressure containment. With direct factory pricing, OEM flange/shaft customization, and proven compatibility with major tractor brands, we serve OEM machinery builders and aftermarket distributors worldwide.
The most reliable starting point is the OEM reference part number stamped on the existing pump housing or listed in your machine parts manual. Also check the nominal displacement (ml/r), maximum pressure rating, rotation direction (viewed from the shaft end), mounting flange dimensions, and inlet/outlet port thread types. If the part number is unreadable, our engineering team can identify or reverse-engineer the pump from clear photos and key physical measurements.
An external gear pump can only pump fluid in one direction determined by its gear rotation and internal pressure balancing plates. If driven in reverse, fluid cannot be drawn from the reservoir; the pump will run dry, cavitate, fail to build pressure, and suffer catastrophic internal seizure within seconds. Always verify whether your pump requires Clockwise (Right-Hand) or Anti-Clockwise (Left-Hand) rotation before installation.
A two-stage pump contains two separate gear sets inside one housing. During the unloaded phase (when the wedge is extending toward the wood), both sections pump together to deliver high fluid volume at low pressure (approx. 2.5 to 5.0 MPa), enabling rapid ram travel. When the wedge contacts the log and pressure rises, an internal unloading valve bypasses the large-displacement section to tank while the small-displacement section continues pumping up to high pressure (20 to 28 MPa). This achieves maximum tonnage without overloading small gas engines (e.g. 5–15 HP).
Yes. We welcome custom manufacturing inquiries based on 2D/3D CAD drawings or physical sample units. We can customize displacement, change mounting flanges (SAE, ISO, or proprietary engine pilot), modify port standards (UNF, BSPP, NPT, Metric), and supply splined, keyed, or tapered shafts for OEM machinery builders.
Send your 2D blueprints or 3D CAD models. Our senior gear engineering team will review tooth geometry, module/pitch, materials, heat treatment feasibility, and provide transparent factory pricing within 24 hours.
Mutual NDA Protection
We sign strict Non-Disclosure Agreements to safeguard proprietary designs.
< 24h DFM Feedback
Rapid manufacturability review, tolerance checks, and unit quotation.
Direct Factory Engineering
Direct technical communication with senior master gear artisans.
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