TECHNICAL WHITE PAPER
HANJIU OMP Series
Orbital Motor
Danfoss OMP Compatible | 14 Displacements | Global Supply Chain Solutions
Low Speed High Torque Hydraulic Motor | Construction, Agriculture, Mining & Industrial Applications
Shijiazhuang Hanjiu Technology Co., Ltd.
June 2025 | www.hjhydraulic.com
Table of Contents
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Executive Summary................................................................................. 3
Chapter 1 Introduction to Orbital Motor Technology............................... 4
1.1 Working Principle of Gerotor Orbital Motors................................. 4
1.2 Danfoss OMP Series as Industry Benchmark.................................. 5
Chapter 2 HANJIU OMP Series Complete Technical Specifications............ 6
2.1 Full Range Displacement Coverage................................................ 6
2.2 Continuous and Intermittent Performance Data............................ 7
2.3 Pressure, Speed and Torque Ratings............................................. 8
Chapter 3 Model Comparison and Cross-Reference Guide........................ 9
3.1 HANJIU vs Danfoss Model Cross-Reference................................... 9
3.2 Compatibility with Other Major Brands....................................... 10
Chapter 4 Spare Parts, Seal Kits and Maintenance Solutions................... 11
4.1 Comprehensive Spare Parts Catalog............................................ 11
4.2 Cost Savings and Lifecycle Analysis.............................................. 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 OMP series orbital hydraulic motor represents a comprehensive solution for low-speed, high-torque power transmission across construction machinery, agricultural equipment, material handling systems, mining operations, and industrial automation. This technical white paper presents the complete HANJIU OMP product line, encompassing 14 displacement variants from OMP 25 through OMP 500, with detailed performance specifications, cross-reference data, spare parts availability, and total cost of ownership analysis.
Shijiazhuang Hanjiu Technology Co., Ltd. has established itself as a leading Chinese manufacturer of orbital hydraulic motors, achieving full dimensional and performance compatibility with the Danfoss OMP series, the industry's most widely recognized benchmark. With annual production exceeding 300,000 units and distribution to over 80 countries worldwide, HANJIU delivers verified quality at significantly reduced acquisition and lifecycle costs, supported by responsive technical service and extensive spare parts inventory.
Keywords: HANJIU orbital motor, OMP hydraulic motor, Danfoss OMP compatible, low speed high torque hydraulic motor, gerotor orbital motor, construction machinery hydraulic motor, agricultural machinery hydraulic motor, hydraulic motor spare parts, orbital motor seal kit
Chapter 1 Introduction to Orbital Motor Technology
1.1 Working Principle of Gerotor Orbital Motors
The orbital hydraulic motor, also known as a gerotor motor, operates on a distinctive mechanical principle that enables exceptional torque generation at low rotational speeds. The core mechanism consists of two primary components: a star-shaped inner rotor with external teeth, and an outer stator ring with precisely machined internal tooth profiles that exceed the rotor tooth count by one.
During operation, high-pressure hydraulic fluid enters the motor and is distributed around the rotor-stator interface through a precision valve plate. The hydraulic pressure forces the rotor to orbit eccentrically within the stator while simultaneously rotating about its own axis. This compound orbital-plus-rotary motion creates a series of expanding and contracting fluid chambers that continuously advance around the periphery, converting hydraulic energy into smooth, powerful shaft rotation.
This design architecture delivers inherent advantages that make orbital motors the preferred choice across numerous industries: extremely high starting torque without minimum speed requirements; smooth, pulsation-free output across the entire speed range; compact power-to-weight ratio; ability to withstand high radial and axial shaft loads; bi-directional operation capability; and proven durability under extreme operating conditions including contamination, temperature variation, and high return pressure.
1.2 Danfoss OMP Series as Industry Benchmark
The Danfoss OMP series has served as the global standard for medium-duty orbital hydraulic motors for over four decades. Characterized by its oval mounting flange (A2 flange), versatile shaft options including cylindrical, splined, and tapered configurations, and displacement range spanning 25 to 400 cubic centimeters per revolution, the OMP series has achieved universal adoption across OEM and aftermarket channels worldwide.
Key distinguishing features of the OMP design include smooth running characteristics across the entire speed envelope, constant operating torque over a wide speed range, high starting torque for demanding load conditions, high return pressure tolerance without requiring external drain connections (when equipped with high-pressure shaft seal), robust construction suitable for both open-loop and closed-loop hydraulic systems, and compatibility with a comprehensive range of hydraulic fluids including mineral oils, biodegradable fluids, and fire-resistant hydraulic media.
Chapter 2 HANJIU OMP Series Complete Technical Specifications
2.1 Full Range Displacement Coverage
The HANJIU OMP series provides comprehensive coverage of the Danfoss OMP displacement spectrum, offering 14 distinct models that enable precise matching to any application requirement. Each model designation corresponds to the nominal geometric displacement in cubic centimeters per revolution:
| OMP 25 | OMP 32 | OMP 40 | OMP 50 | OMP 60 | OMP 80 | OMP 100 |
| 25.0 cm³ | 32.0 cm³ | 40.0 cm³ | 48.6 cm³ | ~60 cm³ | 77.8 cm³ | 97.3 cm³ |
| OMP 125 | OMP 160 | OMP 200 | OMP 250 | OMP 315 | OMP 400 | OMP 500 |
| 120.2 cm³ | 157.2 cm³ | 194.6 cm³ | 240.3 cm³ | 314.5 cm³ | 389.5 cm³ | 486.5 cm³ |
2.2 Continuous and Intermittent Performance Data
The following tables present complete performance data for all HANJIU OMP series orbital motors. Continuous ratings define the parameters for sustained operation with normal service life expectancy. Intermittent ratings apply to short-duration peak loads not exceeding 10% of operating time.
| Model | Disp. (cm³) | Speed (rpm) | Torque (Nm) | Power (kW) | Pressure (bar) | Flow (L/min) |
| OMP 25 | 25.0 | 1600 | 33 | 4.5 | 100 | 40 |
| OMP 32 | 32.0 | 1560 | 43 | 5.8 | 100 | 50 |
| OMP 40 | 40.0 | 1500 | 52 | 7.0 | 100 | 60 |
| OMP 50 | 48.6 | 1230 | 93 | 10.0 | 140 | 60 |
| OMP 80 | 77.8 | 770 | 150 | 10.0 | 140 | 60 |
| OMP 100 | 97.3 | 615 | 190 | 11.0 | 140 | 60 |
| OMP 125 | 120.2 | 490 | 236 | 10.0 | 140 | 60 |
| OMP 160 | 157.2 | 383 | 302 | 10.0 | 140 | 60 |
| OMP 200 | 194.6 | 310 | 360 | 10.0 | 140 | 60 |
| OMP 250 | 240.3 | 250 | 380 | 8.5 | 140 | 60 |
| OMP 315 | 314.5 | 192 | 375 | 7.0 | 140 | 60 |
| OMP 400 | 389.5 | 155 | 435 | 6.0 | 140 | 60 |
| OMP 500 | 486.5 | 120 | 385 | 5.0 | 140 | 60 |
2.3 Pressure, Speed and Torque Ratings
Maximum permissible operating pressure for the HANJIU OMP series reaches 140 bar continuous and 175 bar intermittent across the majority of the product range, with the smaller displacement models (OMP 25 through OMP 40) rated at 100 bar continuous and 140 bar intermittent. Maximum speed capability is inversely proportional to displacement, ranging from 1600 rpm for the OMP 25 down to 120 rpm for the OMP 500, ensuring optimal power density across all application sizes.
Maximum torque output scales directly with displacement, from 33 Nm continuous for the OMP 25 to 435 Nm continuous for the OMP 400. The OMP 500 extends this capability further to 385 Nm continuous. All models exhibit high starting torque, typically 80% to 90% of the rated continuous torque, eliminating the need for auxiliary starting mechanisms in most applications.
Chapter 3 Model Comparison and Cross-Reference Guide
3.1 HANJIU vs Danfoss Model Cross-Reference
The HANJIU OMP series (marketed as BMP/BM1 in certain regions) achieves complete interchangeability with the Danfoss OMP series across all critical dimensions and performance parameters. The following cross-reference table enables direct substitution:
| HANJIU Model | Danfoss Model | HANJIU BMP Code | Notes |
| OMP 25 | OMP 25 | BMP 25 | Direct replacement, all shaft options |
| OMP 32 | OMP 32 | BMP 32 | Direct replacement, all shaft options |
| OMP 40 | OMP 40 | BMP 40 | Direct replacement, all shaft options |
| OMP 50 | OMP 50 | BMP 50 | Reference 11186729 cross-match |
| OMP 80 | OMP 80 | BMP 80 | Popular for agriculture and construction |
| OMP 100 | OMP 100 | BMP 100 | Widely stocked for rapid delivery |
| OMP 125 | OMP 125 | BMP 125 | Balanced torque and speed performance |
| OMP 160 | OMP 160 | BMP 160 | High torque industrial applications |
| OMP 200 | OMP 200 | BMP 200 | Reference 11185705 / 151-0615 |
| OMP 250 | OMP 250 | BMP 250 | Heavy-duty mining and forestry |
| OMP 315 | OMP 315 | BMP 315 | Maximum torque OMP variant |
| OMP 400 | OMP 400 | BMP 400 | Reference 151-0618 cross-match |
| OMP 500 | OMP 500 | BMP 500 | Extended range beyond Danfoss OEM |
Every HANJIU orbital motor undergoes comprehensive dimensional verification, pressure testing, and performance validation to ensure drop-in compatibility. Mounting flange dimensions, shaft configurations, port thread specifications, and overall envelope dimensions match Danfoss OEM specifications precisely, enabling direct replacement without modification to existing equipment or hydraulic systems.
3.2 Compatibility with Other Major Brands
Beyond Danfoss interchangeability, HANJIU OMP series orbital motors also serve as direct replacements for the following internationally recognized brands:
● M+S Hydraulic (Bulgaria) MP and HP series orbital motors
● Eaton Char-Lynn H series low speed high torque motors
● Parker / White Drive TC, TE, and TB series motors
● SAM Brevini BG series orbital motors
● Ross TRW MF and MG series hydraulic motors
● Bosch Rexroth MGP and GXP series gerotor motors
This broad cross-brand compatibility positions HANJIU as a universal solution provider for orbital motor replacement, reducing inventory complexity for distributors and maintenance facilities while ensuring rapid fulfillment regardless of the original equipment manufacturer.
Chapter 4 Spare Parts, Seal Kits and Maintenance Solutions
4.1 Comprehensive Spare Parts Catalog
HANJIU maintains a complete inventory of replacement components for the entire OMP series product line, ensuring that maintenance and repair operations can proceed without delay. Available spare parts include:
| Part Description | HANJIU Part Code | Application |
| Complete Seal Kit (Standard) | SK-OMP-STD | All OMP models, standard shaft seal |
| Complete Seal Kit (HPS) | SK-OMP-HPS | All OMP models, high pressure shaft seal |
| Gerotor Set (Rotor + Stator) | GS-OMP-XXX | Model-specific, replace XXX with displacement |
| Valve Plate / Distributor | VP-OMP-STD | Standard configuration, all models |
| Output Shaft (Cylindrical 25mm) | OS-OMP-C25 | Standard shaft option |
| Output Shaft (Cylindrical 1 inch) | OS-OMP-C1 | North American standard |
| Output Shaft (Splined 1 inch) | OS-OMP-S1 | High torque transmission option |
| Needle Bearing Set | NB-OMP-SET | For OMPW wheel motor variants |
| Slide Bearing Set | SB-OMP-SET | Standard bearing configuration |
| Check Valve Cartridge | CV-OMP-STD | For motors with integrated check valves |
| Mounting Flange Gasket | MF-OMP-A2 | A2 flange oval pattern gasket |
4.2 Cost Savings and Lifecycle Analysis
Implementing HANJIU OMP orbital motors and genuine spare parts delivers measurable economic benefits throughout the equipment lifecycle:
● Acquisition cost reduction of 35% to 55% compared to original Danfoss equipment, with no compromise in performance or service life
● Complete seal kit replacement cost savings of 40% to 60%, with all kits including precision-matched seals, O-rings, and gaskets
● Standard delivery lead times of 1 to 7 days globally, with 24-hour express dispatch for urgent requirements, minimizing equipment downtime
● Extended motor service life achieved through consistent availability of genuine replacement parts, reducing total cost of ownership by 25% to 35% over the equipment lifecycle
● Free technical consultation and troubleshooting support provided by qualified hydraulic engineers with average response time under 2 hours
Chapter 5 Applications Across Industries
The HANJIU OMP series orbital motor serves an exceptionally diverse range of applications across multiple industry sectors, leveraging its high starting torque, compact dimensions, and reliable performance under demanding conditions.
5.1 Construction Machinery
Construction equipment represents one of the largest application segments for OMP series orbital motors. Typical installations include swing drives for mini excavators and compact loaders, wheel drive systems for skid-steer loaders and compact track loaders, auger drives for post-hole diggers and foundation drilling equipment, winch drives for utility trucks and crane booms, and concrete mixer drum rotation systems. The OMP 50 through OMP 200 models predominate in this sector, providing the torque and durability required for continuous-duty earthmoving and material handling operations.
5.2 Agricultural Machinery
Modern agricultural equipment relies extensively on orbital motors for functions including combine harvester reel and auger drives, tractor-mounted implement power such as mowers, tillers, and balers, center-pivot irrigation system propulsion, vineyard and orchard sprayer fan drives, and livestock feed mixer wagon drives. The OMP 80, OMP 100, and OMP 160 models are particularly well-suited to agricultural applications where resistance to contamination, temperature variation, and intermittent heavy loading are essential.
5.3 Mining, Forestry and Marine Applications
In the mining sector, OMP motors power drilling rig rotation heads, conveyor belt drives, and underground utility vehicle traction systems. Forestry equipment utilizes these motors for log grapple rotation, harvester head drives, and forwarder crane articulation. Marine applications include anchor winch drives, capstan operations, hatch cover actuators, and fishing equipment deployment systems. The larger displacement models including OMP 250, OMP 315, and OMP 400 provide the substantial torque output required by these demanding applications.
5.4 Industrial and Special Purpose Equipment
Industrial automation applications encompass conveyor systems, mixing and blending equipment, rotary indexing tables, plastic injection mold handling, and textile machinery. Special purpose installations include road sweeper brush drives, airport runway maintenance equipment, snow blower auger and discharge chute rotation, turf care machinery reel drives, and waste management equipment compaction systems. The HANJIU OMP series provides the versatility to satisfy virtually any low-speed, high-torque hydraulic power requirement.
Chapter 6 Quality Assurance and Global Distribution
HANJIU Technology operates a state-of-the-art manufacturing facility in Shijiazhuang, Hebei Province, China, equipped with precision CNC machining centers, automated assembly lines, and comprehensive testing equipment. The quality management system has been certified to ISO 9001 standards, ensuring consistent product quality and continuous process improvement.
● Every HANJIU orbital motor undergoes 100% pressure testing at 1.5 times maximum rated pressure to verify housing integrity and seal performance
● Performance testing confirms output speed, torque, and volumetric efficiency within specified tolerances for every unit produced
● Dimensional inspection using precision measurement equipment ensures interchangeability with Danfoss and other OEM specifications
● CE marking compliance confirms adherence to European machinery safety directives for all products exported to EU markets
● All motors are delivered with 12-month warranty coverage against defects in materials and workmanship under normal operating conditions
The global distribution network encompasses authorized dealers and service partners across more than 80 countries, with strategic warehouse locations ensuring rapid delivery to major markets. HANJIU's export volumes have grown consistently year-over-year, reflecting the confidence of international customers in product quality, competitive pricing, and responsive service.
Chapter 7 Ordering Guide and Technical Support
Specifying the correct HANJIU OMP orbital motor for a given application requires consideration of several key parameters. The selection process begins with determining the required torque at the specified operating pressure, then verifying that the resulting flow rate and speed fall within the motor's continuous rating envelope.
7.1 Selection Procedure
● Step 1: Calculate required torque including application safety factor (typically 1.2 to 1.5)
● Step 2: Determine available system pressure and verify motor pressure rating adequacy
● Step 3: Calculate required flow rate based on desired output speed and selected displacement
● Step 4: Verify that calculated speed, flow, and pressure all fall within continuous ratings
● Step 5: Select shaft type, mounting flange, and port configuration to match installation requirements
7.2 Technical Support Channels
HANJIU Technology provides comprehensive technical support through multiple channels: direct telephone consultation during business hours; email technical inquiry with guaranteed response within 2 hours; online documentation including datasheets, installation manuals, and troubleshooting guides; video technical support for complex diagnostic situations; and on-site field service for major accounts and distributors. The technical support team comprises qualified hydraulic engineers with extensive practical experience across construction, agricultural, mining, and industrial applications.
Conclusion
The HANJIU OMP series orbital hydraulic motor offers a compelling combination of verified quality, comprehensive specification coverage, and significant cost advantage for OEM and aftermarket applications worldwide. With 14 displacement variants providing continuous torque from 33 Nm to 435 Nm, pressure ratings to 175 bar, and complete dimensional interchangeability with the Danfoss OMP series, HANJIU addresses the full spectrum of low-speed, high-torque hydraulic power requirements.
The extensive spare parts availability, responsive technical support, and proven global distribution network position HANJIU as a reliable long-term partner for equipment manufacturers, hydraulic distributors, and maintenance organizations seeking to optimize procurement costs without compromising operational reliability. As hydraulic technology continues to evolve toward higher efficiency and smarter integration, HANJIU remains committed to advancing its orbital motor product line through continued innovation and investment in manufacturing excellence.
References
[1] Danfoss Power Solutions. Orbital Motors Type OMP, OMR and OMH Technical Information [520L0262 Rev DA]. 2014.
[2] Danfoss Power Solutions. OMP X 50 Orbital Motor Datasheet [Reference 11186729]. 2023.
[3] Danfoss Power Solutions. OMP X 200 Orbital Motor Datasheet [Reference 11185705]. 2023.
[4] Shijiazhuang Hanjiu Technology Co., Ltd. HANJIU OMP Series Orbital Motor Product Catalog. 2024.
[5] Shijiazhuang Hanjiu Technology Co., Ltd. Model Cross Reference Guide: HANJIU vs Danfoss, Eaton, M+S. 2024.
[6] ISO 9001:2015. Quality Management Systems - Requirements. International Organization for Standardization.
[7] Directive 2006/42/EC. Machinery Directive. European Parliament and Council.
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