TECHNICAL WHITE PAPER
HANJIU OMH Series
Orbital Motor
Danfoss OMH Compatible | Large Displacement | High Torque Design
OMH 200 · 250 · 315 · 400 · 500
Shijiazhuang Hanjiu Technology Co., Ltd.
June 2025 | www.hjhydraulic.com
Table of Contents
Executive Summary................................................................................. 3
Chapter 1 OMH Series: Large Displacement Orbital Motor Technology..... 4
1.1 Roller Gear Ring Mechanism and Operating Principle..................... 4
1.2 OMH vs OMR: Structural and Performance Differentiators............. 5
Chapter 2 HANJIU OMH Complete Technical Specifications...................... 6
2.1 Five-Model Displacement Range................................................... 6
2.2 Continuous and Intermittent Performance Data............................ 7
2.3 Pressure, Torque and Speed Envelope.......................................... 8
Chapter 3 Cross-Reference and Compatibility Guide................................ 9
3.1 HANJIU OMH vs Danfoss OMH Cross-Reference............................. 9
3.2 Multi-Brand Interchangeability................................................... 10
Chapter 4 Spare Parts, Seal Kits and Service Solutions............................ 11
4.1 Core Spare Parts Catalog............................................................ 11
4.2 Maintenance Cost Optimization.................................................. 12
Chapter 5 Applications Across Industries............................................... 13
Chapter 6 Quality Assurance and Global Distribution............................. 15
Chapter 7 Ordering Guide and Technical Support................................... 17
Conclusion............................................................................................ 19
References............................................................................................ 20
Executive Summary
The HANJIU OMH series large-displacement orbital hydraulic motor delivers exceptional torque output and robust bearing capacity for applications that exceed the capabilities of standard medium-duty orbital motors. Positioned as the bridge between the OMR series and the heavy-duty OMS/OMT families, the OMH series features large-displacement gerotor sets, reinforced A4 mounting flanges, and oversized shaft bearings to handle extreme radial and axial loads. This white paper presents the complete HANJIU OMH product line covering five displacement models from OMH 200 through OMH 500, with comprehensive technical specifications, cross-reference data, and aftermarket support information.
Shijiazhuang Hanjiu Technology Co., Ltd. has developed its OMH series to achieve complete dimensional and performance interchangeability with the Danfoss OMH series, the globally recognized standard for large-displacement orbital hydraulic power. With geometric displacements ranging from 201.3 cm³ to 470.6 cm³, continuous torque output up to 340 Nm, and peak intermittent torque reaching 540 Nm, HANJIU OMH motors provide a high-performance, cost-effective alternative for OEM equipment builders, hydraulic system designers, and aftermarket service providers serving construction, mining, forestry, and marine industries worldwide.
Keywords: HANJIU OMH orbital motor, large displacement hydraulic motor, Danfoss OMH compatible, OMH 200 OMH 250 OMH 315 OMH 400 OMH 500, low speed high torque hydraulic motor, roller gear ring orbital motor, heavy duty construction machinery hydraulic motor, mining equipment hydraulic motor, hydraulic motor spare parts, orbital motor seal kit
Chapter 1 OMH Series: Large Displacement Orbital Motor Technology
1.1 Roller Gear Ring Mechanism and Operating Principle
The HANJIU OMH series, like all modern orbital hydraulic motors, converts hydraulic energy into mechanical rotation through a gerotor mechanism enhanced by a roller gear ring. The internal geometry consists of a fixed stator ring with precision-machined internal teeth and a star-shaped rotor with external teeth that mesh within the stator bore. The tooth count differential between stator and rotor creates a series of sealed chambers that progressively expand and contract as the rotor orbits and rotates.
The defining characteristic of the OMH design is the roller-equipped gear ring: cylindrical rollers are seated in each stator tooth pocket, establishing a rolling contact interface with the rotor teeth. This architecture delivers significant performance advantages over sliding-contact designs: rolling friction is inherently lower than sliding friction, reducing internal mechanical losses and improving overall efficiency; wear on the tooth profiles is dramatically reduced, extending service life under continuous high-pressure operation; and the roller distribution increases the effective load-bearing contact area, enabling higher torque transmission without component fatigue.
The distributor valve, integrated coaxially with the output shaft, employs a precision spool-type design to sequentially direct hydraulic fluid to the expanding chambers while evacuating fluid from the contracting chambers. This integrated valve eliminates the need for external timing mechanisms and ensures precise porting regardless of operating speed or pressure. The fixed ring gear mechanism converts the compound orbital-rotary motion of the rotor into pure rotary output at the shaft, delivering smooth, high-torque rotation at speeds from near-zero to maximum rated rpm.
1.2 OMH vs OMR: Structural and Performance Differentiators
While the OMH and OMR series share the same roller gear ring operating principle, the OMH incorporates substantial structural enhancements that elevate it to a higher displacement and load-bearing class. These differences make the OMH the motor of choice when application demands exceed the capacity of medium-duty alternatives:
● Displacement range: OMH motors cover 201.3 to 470.6 cm³, significantly larger than the OMR range of 51.6 to 397.0 cm³, providing torque output for the heaviest mobile equipment applications
● Mounting flange: the OMH employs a robust A4 4-hole oval flange rather than the OMR's A2 2-hole flange, providing superior structural attachment for high-torque reactions and shock loading
● Shaft bearing capacity: OMH shaft bearings are dimensioned for substantially higher radial and axial loads, permitting direct-drive installations without external bearing support in most applications
● Shaft diameter: standard OMH shaft options include 32 mm and 35 mm cylindrical shafts, larger than the OMR's maximum 32 mm, enabling higher torque transmission
● Maximum return pressure: the OMH achieves 200 bar continuous return pressure (with drain line), compared to 175 bar for the OMR, supporting closed-loop and regenerative circuit applications
● Port sizing: OMH main ports are sized at G1/2 (BSP) or 7/8-14 UNF O-ring boss, providing higher flow capacity than the OMR's G1/2 configuration
● Overall envelope: the OMH is approximately 15% to 20% larger and heavier than the corresponding OMR displacement model, reflecting the increased structural robustness
Chapter 2 HANJIU OMH Complete Technical Specifications
2.1 Five-Model Displacement Range
The HANJIU OMH series encompasses five large-displacement models providing continuous torque output from 340 Nm at the OMH 200 to comparable levels at the OMH 500, with each model optimized for a specific operating envelope. All five models share common shaft, flange, and port interface dimensions, simplifying inventory management for distributors and maintenance facilities:
| OMH 200 | OMH 250 | OMH 315 | OMH 400 | OMH 500 |
| 201.3 cm³ | 252.0 cm³ | 314.9 cm³ | 396.8 cm³ | 470.6 cm³ |
| A4 Flange | A4 Flange | A4 Flange | A4 Flange | A4 Flange |
| 4-hole oval | 4-hole oval | 4-hole oval | 4-hole oval | 4-hole oval |
2.2 Continuous and Intermittent Performance Data
The following table presents verified continuous-duty and intermittent-duty performance specifications for all HANJIU OMH series orbital motors. Continuous ratings define sustained operation for normal service life. Intermittent ratings apply to peak loads not exceeding 10% of operating cycle time. All data measured with ISO VG 46 mineral hydraulic oil at 50°C and 35 mm²/s viscosity:
| Model | Disp. | Speed | Torque | Power | Press. | Press. | Flow | Flow |
| (cm³) | (rpm) | (Nm) | (kW) | Cont.(bar) | Int.(bar) | Cont.(L/m) | Int.(L/m) | |
| OMH 200 | 201.3 | 370 | 340 | 11.2 | 115 | 170 | 75 | 90 |
| OMH 250 | 252.0 | 295 |
340 | 7.5 | 90 | 145 | 75 | 90 |
| OMH 315 | 314.9 | 235 | 340 | 5.2 | 75 | 120 | 75 | 90 |
| OMH 400 | 396.8 | 185 | 340 | 4.8 | 60 | 95 | 75 | 90 |
| OMH 500 | 470.6 | 155 | 340 | 3.7 | 50 | 75 | 75 | 90 |
2.3 Pressure, Torque and Speed Envelope
The HANJIU OMH series exhibits a distinctive performance envelope optimized for large-displacement, low-speed, high-torque applications. Maximum continuous pressure drop ranges from 115 bar (OMH 200) to 50 bar (OMH 500), while intermittent pressure drop capability extends from 170 bar to 75 bar respectively. Peak pressure capability reaches 225 bar for the OMH 200 and 250 models, providing substantial overload margin for shock load conditions.
Maximum operating speed varies inversely with displacement, from 370 rpm continuous for the OMH 200 to 155 rpm continuous for the OMH 500. Intermittent speed ratings extend these limits by approximately 20% for short-duration operation. Maximum continuous output torque is rated at 340 Nm across the OMH 200, 250, 315, and 400 models, with the OMH 500 delivering 340 Nm continuous and 520 Nm intermittent.
Maximum output power at continuous duty reaches 11.2 kW for the OMH 200, declining to 3.7 kW for the OMH 500 as the operating envelope shifts toward torque-dominant applications. All models achieve high starting torque, averaging 85% to 90% of rated continuous torque, ensuring reliable cold-start performance under full load. Volumetric efficiency exceeds 90% across the specified speed and pressure ranges, with overall efficiency reaching 80% at optimum operating points.
Maximum permissible return pressure with drain line connection reaches 200 bar continuous, 225 bar intermittent, and 250 bar peak for all OMH models, enabling closed-loop and regenerative circuit operation without external drain plumbing. The high-pressure shaft seal (HPS) option is recommended for applications where return line pressure exceeds 50 bar.
Chapter 3 Cross-Reference and Compatibility Guide
3.1 HANJIU OMH vs Danfoss OMH Cross-Reference
HANJIU OMH series orbital motors achieve verified dimensional and functional interchangeability with the Danfoss OMH series. The following cross-reference table provides direct model mapping for replacement, retrofit, and new equipment design applications:
| HANJIU Model | Danfoss Model | HANJIU BMH Code | Compatibility Notes |
| OMH 200 | OMH 200 | BMH 200 | Direct replacement, all shaft options |
| OMH 250 | OMH 250 | BMH 250 | Direct replacement, all shaft options |
| OMH 315 | OMH 315 | BMH 315 | Popular for construction and mining |
| OMH 400 | OMH 400 | BMH 400 | Heavy-duty material handling |
| OMH 500 | OMH 500 | BMH 500 | Largest OMH displacement available |
Every HANJIU OMH motor undergoes 100% dimensional verification, hydrostatic pressure testing at 1.5 times rated maximum pressure, and performance validation confirming output speed, torque, and volumetric efficiency within specification tolerances. Mounting flange geometry, shaft configurations, port thread specifications, and overall envelope dimensions conform to Danfoss OEM standards, ensuring direct drop-in replacement without system modification.
3.2 Multi-Brand Interchangeability
Beyond Danfoss compatibility, HANJIU OMH series motors serve as direct replacements for the following major international brands, providing a universal solution for large-displacement orbital motor requirements:
● M+S Hydraulic (Bulgaria) MH series large-displacement orbital motors
● Eaton Char-Lynn 2000 series and 4000 series low speed high torque motors
● Parker / White Drive TG and DF series large-displacement motors
● SAM Brevini BGH and BGHT series heavy-duty orbital motors
● Bosch Rexroth MCR3 and MCR5 series radial piston and gerotor motors
● Intermot NAM and NHM series large orbital hydraulic motors
Chapter 4 Spare Parts, Seal Kits and Service Solutions
4.1 Core Spare Parts Catalog
HANJIU maintains a comprehensive inventory of genuine replacement components for the entire OMH series, supporting both preventive maintenance programs and field repair operations. The spare parts catalog encompasses:
| Part Description | HANJIU Part Code | Application |
| Complete Seal Kit (Standard) | SK-OMH-STD | All OMH models, standard shaft seal |
| Complete Seal Kit (HPS) | SK-OMH-HPS | All OMH models, high-pressure shaft seal |
| Gerotor Set (Rotor + Stator + Rollers) | GS-OMH-XXX | Model-specific roller gear ring set |
| Distributor Valve / Spool Valve | DV-OMH-STD | Standard valve, all models |
| Output Shaft (32 mm Cylindrical) | OS-OMH-C32 | Standard shaft option |
| Output Shaft (35 mm Cylindrical) | OS-OMH-C35 | Heavy-duty shaft option |
| Output Shaft (SAE 6B Splined 1 in) | OS-OMH-S1 | High torque transmission |
| Output Shaft (Tapered 35 mm 1:10) | OS-OMH-T35 | Precision coupling applications |
| A4 Mounting Flange Gasket | MF-OMH-A4 | 4-hole oval flange gasket |
| Slide Bearing Set | SB-OMH-SET | Standard bearing configuration |
4.2 Maintenance Cost Optimization
Selecting HANJIU OMH orbital motors and genuine spare parts delivers significant economic advantages throughout the equipment ownership lifecycle:
● Acquisition cost reduction of 35% to 55% versus original Danfoss equipment, with verified equivalent performance and service life expectancy
● Complete seal kit replacement costs 40% to 60% below OEM pricing, with all kits including precision-matched shaft seals, O-rings, and gaskets
● Standard delivery lead times of 1 to 7 days globally, with 24-hour emergency dispatch available for critical requirements
● Total cost of ownership reduction of 25% to 35% achieved through consistent parts availability, extended motor service life, and minimized equipment downtime
● Complimentary technical consultation provided by qualified hydraulic engineers with average response time under 2 hours
Chapter 5 Applications Across Industries
The HANJIU OMH series large-displacement orbital motor serves demanding applications across multiple industry sectors where high torque at low speed, robust bearing capacity, and proven durability under extreme conditions are essential requirements.
5.1 Construction and Earthmoving Equipment
Construction machinery constitutes the primary application segment for OMH series orbital motors. Typical installations include hydraulic excavator swing drives for machines from 8 to 20 tons, wheel loader axle and wheel drives for articulated loaders, backhoe loader stabilizer leg and bucket crowd drives, skid-steer loader and compact track loader propulsion systems, road roller drum vibration and travel drives, concrete pump truck slewing and outrigger drives, and crane and aerial work platform lift and slew mechanisms. The OMH 200 and OMH 250 models predominate in construction applications, where their combination of high torque and moderate speed delivers the precise, powerful motion control required by earthmoving and material handling equipment.
5.2 Mining and Heavy Material Handling
Mining operations subject hydraulic components to continuous high-load duty cycles in abrasive, contaminated environments. The OMH series powers underground LHD vehicle traction and bucket rotation drives, roof bolter drill head and feed drives, portable crushing and screening plant conveyor systems, and stacker-reclaimer boom and bucket wheel drives. In port and terminal operations, OMH motors drive ship loader and unloaders, container handling equipment, and bulk material conveyor systems. The OMH 315, OMH 400, and OMH 500 models provide the substantial torque output required by these continuous-duty heavy material handling applications.
5.3 Forestry, Agriculture and Marine
In the forestry sector, OMH motors power log forwarder and skidder winch drives, harvester head rotation and feedroll mechanisms, and delimber arm actuation systems. Agricultural applications include large forage harvester header and kernel processor drives, combine harvester reel and unloading auger systems, and large-scale center-pivot irrigation propulsion. Marine installations encompass anchor winch and windlass drives, capstan and mooring systems, commercial fishing net and longline haulers, and stern ramp and hatch cover actuators. The OMH's high return pressure tolerance and robust shaft seal options make it particularly well-suited to marine environments where system back pressure is inherently elevated.
5.4 Industrial and Specialized Equipment
Industrial applications include heavy conveyor belt drives, rotary drum mixer and blender drives, large indexing table and positioning systems, plastic extrusion and injection mold handling, automated guided vehicle and mobile robot propulsion, and steel mill auxiliary equipment drives. Specialized installations span tunnel boring machine cutter head drives, offshore platform equipment, wind turbine pitch and yaw systems, and amusement ride motion platforms. The OMH 200 and OMH 250 are the most commonly specified models for industrial applications, where their high torque density and smooth speed control characteristics deliver precise, reliable motion.
Chapter 6 Quality Assurance and Global Distribution
HANJIU Technology operates a vertically integrated manufacturing facility in Shijiazhuang featuring CNC machining centers, automated gerotor set production lines, precision assembly stations, and comprehensive testing and validation equipment. The quality management system is certified to ISO 9001:2015 standards, with CE marking compliance for all products supplied to European Union markets.
● 100% hydrostatic pressure testing: every OMH motor is pressure-tested at 1.5 times maximum rated working pressure to verify housing integrity, seal performance, and absence of leakage
● Performance validation: output speed, torque, and volumetric efficiency are measured and recorded for each production unit against specification tolerances
● Dimensional verification: precision measurement using coordinate measuring machines and conventional metrology confirms interchangeability with Danfoss OEM dimensions
● Material certification: nodular cast iron housings, alloy steel shafts, and precision gerotor sets sourced from qualified suppliers with full material traceability
● Warranty coverage: 12-month warranty against defects in materials and workmanship under normal operating conditions
The global distribution network serves customers in more than 80 countries through authorized dealers, OEM direct accounts, and aftermarket distributors. Strategic regional warehouse locations in Europe, North America, Southeast Asia, and the Middle East ensure delivery times of 1 to 7 days for standard orders. HANJIU's commitment to quality, competitive pricing, and responsive customer service has driven consistent double-digit annual growth in international export volumes.
Chapter 7 Ordering Guide and Technical Support
7.1 Selection Procedure
Specifying the correct HANJIU OMH orbital motor follows a systematic engineering procedure:
● Step 1: Calculate required output torque including application service factor (typically 1.25 to 1.5 for construction and mining equipment)
● Step 2: Determine available system working pressure and confirm motor pressure rating adequacy for continuous or intermittent duty
● Step 3: Calculate required hydraulic flow rate: Q = Vg x n / 1000 (L/min), where Vg is displacement in cm³ and n is desired speed in rpm
● Step 4: Verify that calculated speed, flow, and pressure all fall within the motor's continuous duty envelope
● Step 5: Select shaft type (32 mm or 35 mm cylindrical, SAE 6B splined, or tapered), A4 flange configuration, and port thread specification
● Step 6: Specify shaft seal configuration (standard or high-pressure HPS) based on expected return line back pressure
7.2 Technical Support Channels
HANJIU Technology provides comprehensive technical support through multiple channels: direct telephone consultation during extended business hours (China Standard Time); email technical inquiry with guaranteed response within 2 hours during business hours; complete technical documentation including datasheets, installation manuals, troubleshooting guides, and hydraulic schematic diagrams available for download; video technical support and remote diagnostic assistance for complex application challenges; and on-site field service for major OEM accounts and distribution partners. The technical support team comprises qualified hydraulic engineers with decades of combined experience across construction machinery, mining equipment, agricultural systems, marine hydraulics, and industrial automation.
Conclusion
The HANJIU OMH series large-displacement orbital hydraulic motor delivers proven performance for the most demanding low-speed, high-torque applications across construction, mining, forestry, agriculture, marine, and industrial sectors. With five displacement models from OMH 200 to OMH 500 delivering geometric displacements from 201.3 cm³ to 470.6 cm³, continuous torque output to 340 Nm, peak intermittent torque to 540 Nm, and complete dimensional interchangeability with the Danfoss OMH series, HANJIU addresses the full spectrum of large-displacement hydraulic power transmission requirements.
The roller gear ring mechanism, reinforced A4 mounting flange, oversized shaft bearings, and high return pressure tolerance position the OMH series as the motor of choice for heavy-duty mobile equipment and industrial systems. Combined with extensive spare parts availability, competitive lifecycle costs, and responsive global technical support, HANJIU OMH orbital motors deliver tangible value that strengthens OEM competitiveness and reduces operating costs for end-user equipment fleets. As the industry advances toward higher efficiency and smarter hydraulic integration, HANJIU remains committed to advancing its OMH product line through sustained engineering investment and manufacturing excellence.
References
[1] Danfoss Power Solutions. Orbital Motors Type OMP, OMR and OMH Technical Information [151-1013]. 2011.
[2] Danfoss Power Solutions. OMH Technical Data and Function Diagrams [151-1850 through 151-1854]. 2023.
[3] Danfoss Power Solutions. OMH Dimensions European and US Versions [151-1857 through 151-1859]. 2023.
[4] Zeus Hydratech. Sauer Danfoss OMH Orbital Motors Technical Data. 2024.
[5] Shijiazhuang Hanjiu Technology Co., Ltd. HANJIU OMH Series Orbital Motor Product Catalog. 2024.
[6] Shijiazhuang Hanjiu Technology Co., Ltd. Model Cross Reference Guide: HANJIU OMH vs Danfoss, Eaton, M+S. 2024.
[7] ISO 9001:2015. Quality Management Systems - Requirements. International Organization for Standardization.
[8] Directive 2006/42/EC. Machinery Directive. European Parliament and Council.