Product Overview
The OMP125 151B-0313 is a 125-displacement model in Danfoss’s OMP Series of medium-duty, low-speed high-torque (LSHT) orbital hydraulic motors, with a geometric displacement of 123.8 cm³/rev. The OMP Series is Danfoss‘s classic gerotor motor line, recognized for its compact design, high starting torque, and the ability to withstand high return-line pressure without a case drain line.
The OMP125 151B-0313 features a 25 mm cylindrical shaft with an A8×7×32 mm parallel key (DIN 6885), an A2 two-bolt flange mounting, side ports in G 1/2, and a standard G 1/4 drain port. The motor housing is cast iron, equipped with a reinforced shaft seal that allows elevated return-line pressure without an external case drain, simplifying system layout.
Each OMP125 151B-0313 undergoes 100% simulated duty-cycle testing prior to shipment, validating volumetric efficiency and torque output under both dynamic instantaneous and static steady loads. Dimensional and functional interchangeability with the original Danfoss motor ensures true drop-in replacement—mounting flange, shaft configuration, and port geometry all match Danfoss OEM specifications.
Technical Specifications
Model: OMP125 151B-0313
Series: Danfoss OMP Series
Motor Type: Gerotor Orbital Motor
Geometric Displacement: 123.8 cm³/rev
Maximum Speed (Continuous): 490 rpm
Maximum Speed (Intermittent): 590 rpm
Maximum Differential Pressure (Continuous): 140 bar
Maximum Differential Pressure (Intermittent): 175 bar
Maximum Peak Pressure: 225 bar
Maximum Torque (Continuous): 237 Nm
Maximum Torque (Intermittent): 285 Nm
Maximum Power (Continuous): 10 kW
Maximum Oil Flow (Continuous): 60 L/min
Maximum Oil Flow (Intermittent): 75 L/min
Mounting Flange: A2 Two-Bolt, 82.5 mm Pilot, 106.4 mm Bolt Circle
Shaft: 25 mm Cylindrical, A8×7×32 mm Key (DIN 6885)
Ports: G 1/2 Side Ported
Drain Port: G 1/4
Housing Material: Cast Iron
Weight: Approx. 6.0 kg
Key Technical Advantages
Gerotor design with high starting torque. The OMP125 utilizes Danfoss’s classic gerotor rotor set, where the rotor-stator pair forms a dynamic seal under high-pressure oil film action, delivering high torque from startup. The OMP Series maintains constant output torque characteristics across all displacement sizes, ensuring stable and reliable drive force under varying operating conditions.
High return pressure capability without case drain. The OMP Series features a reinforced shaft seal as standard, allowing significantly elevated return-line pressure without an external case drain line. This design offers dual engineering value: it eliminates an additional hydraulic connection and its associated leak potential, simplifying system layout, and reduces installation space requirements—particularly beneficial in space-constrained applications.
Cast iron housing with compact structure. The OMP125 uses a cast iron housing, offering higher rigidity and wear resistance than aluminum alternatives. Housing deformation under high pressure is minimized, helping maintain distribution accuracy and sealing reliability. The motor‘s compact overall structure delivers high power density, providing exceptional torque output within a limited envelope.
Broad hydraulic fluid compatibility. The OMP Series is compatible with a wide range of hydraulic fluids and can operate in both open and closed circuits. Brake options are available for applications requiring parking brakes. High volumetric efficiency ensures stable output performance across the entire speed range.
Application Areas
Agricultural auger drives
Combine harvester drive systems
Seeder and spreader drives
Skid steer attachments
Small winches and hoists
Conveyor drives
Sweeper brush drives
Marine deck machinery
Industrial mixing equipment
Aerial work platform drives
Expert Maintenance Tips
Verify model variant before installation. The 151B-0313 and 151-0313 are the same model under different numbering systems, and the OMP125 also exists as variant 151-0613, with differences primarily in port configuration or seal material. When replacing an original motor, confirm the complete model code on the nameplate, and verify shaft type (cylindrical/splined) and port dimensions.
Prime and bleed before first start. After initial installation or extended storage, air may be trapped within the motor casing. Fill the casing with clean hydraulic oil through the highest port before startup, then jog the motor at low pressure (≤30 bar) several times to purge residual air. Apply full working pressure only after the motor runs smoothly. Inadequate bleeding may cause low-speed stick-slip or abnormal noise.
Maintain oil cleanliness and viscosity. Premium quality anti-wear hydraulic oil is recommended, with a viscosity range of 20-75 cSt and maximum oil temperature not exceeding 80°C. System cleanliness should meet ISO 18/16/13 or better. The OMP Series gerotor set is sensitive to particulate contamination; inadequate cleanliness accelerates rotor-stator wear.
Inspect shaft seal and drain port periodically. The OMP125 features a reinforced shaft seal as standard, but continuous operation at high return pressure accelerates seal aging. Inspect the shaft seal for weeping or dripping every 2,000 operating hours, and verify the drain port remains unobstructed. If seal leakage is detected, replace the seal kit promptly.
