BM4 BMT OMT Orbital Hydraulic Motor | Danfoss OMT Replacement

Genlu Hydraulic proudly introduces our BM4 / BMT / OMT Series heavy-duty industrial and mobile-grade high-torque low-speed (LSHT) orbital hydraulic motors. Engineered to deliver unyielding continuous torque, superior radial/axial load compliance, and outstanding mechanical start-up tracking under punishing environmental conditions, this line serves as a precision-manufactured, drop-in replacement for the industry-standard Danfoss OMT series and domestic benchmark BM4 disc-valve orbital configurations. We specialize in cross-referencing and supplying the full displacement spectrum, notably 160, 200, 230, 250, 315, 400, 500, 630, and 800 cc/rev variants, available with diverse standard flanges, splined/keyed shafts, and integrated wet disc brake modifications.

Acting as the fundamental mechanical motive source for high-resistance rotary mechanisms—such as tracked undercarriages, winch drums, and heavy-duty augers—Genlu’s BM4/BMT series conforms strictly to international geometric standards. We guarantee 100% Drop-in Interchangeability across standard mounting footprints (standard 4-bolt square or wheel-mount flanges), output shaft profiles (metric parallel keyed, SAE splined, or tapered shafts), port sizing matrices, and low-speed stability curves. Every single production unit undergoes 100% full-load low-speed anti-stalling qualification, continuous peak torque sweeps, and shaft-chamber high-backpressure leakage audits, ensuring lag-free reversing and an extensive wear lifecycle under volatile load shifts.

Technical Specifications 

• Product Line: BM4 / BMT / OMT Series Fixed Displacement Disc-Valve Orbital Hydraulic Motor

• Displacement Parameters (Theoretical Volumetric Output):

  • OMT/BMT 160 Model: 160.8 $cc/rev$

  • OMT/BMT 200 Model: 200.9 $cc/rev$

  • OMT/BMT 250 Model: 252.2 $cc/rev$

  • OMT/BMT 315 Model: 314.5 $cc/rev$

  • OMT/BMT 400 Model: 400.9 $cc/rev$

  • OMT/BMT 500 Model: 502.5 $cc/rev$

  • OMT/BMT 630 Model: 629.1 $cc/rev$

  • OMT/BMT 800 Model: 798.5 $cc/rev$

• Maximum Continuous Working Pressure: Ranges from 20.0 MPa (200 bar) down to 12.0 MPa (120 bar) (Gradually scaled relative to larger displacement frames)

• Maximum Intermittent Peak Pressure: 24.0 MPa (240 bar)

• Maximum Continuous Output Torque: Up to 1250 Nm (Intermittent peak peaks up to 1400 Nm on large-frame models)

• Rotational Velocity Envelopes (Continuous): 30 rpm to 625 rpm (High speed for smaller frames; heavy torque/low speed for larger profiles)

• Drive Configuration: Fixed displacement geroler gear set geometry, where output velocity is strictly proportional to the input volume stream

• Output Shaft Formats: $\Phi 38.1$ splined shaft / $\Phi 40$ cylindrical parallel keyed shaft / $\Phi 45$ tapered shaft

• Port Sizing Layout: Standard G 3/4 main threaded pressure ports with an independent G 1/4 case drain terminal

Key Technical Advantages:

• Advanced Geroler Gear Set with Rollers for Extended Service Life: Features an engineered design integrating hydrodynamic rollers into the orbit rotor envelope. By replacing sliding friction with rolling friction, the motor maintains stable operation at extremely low speeds (<30 rpm), completely eliminating stick-slip jitter while securing a mechanical startup torque efficiency exceeding 85%.

• Independent Disc Valve Distribution with Wear Compensation: Incorporates a separate disc-valve face-distribution array driven synchronously by a dedicated drive link. This configuration provides automatic wear compensation under continuous 20 MPa pressure, preserving high volumetric retention over time and offering superior tolerance against microscopic particulate fluid contamination.

• Tapered Roller Bearings for High Radial and Axial Load Capacity: The output shaft is mounted within heavy-duty, paired tapered roller bearings at both front and rear positions. This robust design allows the assembly to directly withstand radial loads up to 30 kN and significant axial thrusts, enabling direct coupling to drive wheels or winch drums without additional outboard bearing blocks.

• High-Pressure Shaft Sealing with Internal Check Valves: Outfitted with a premium heavy-capacity shaft lip-seal assembly capable of handling casing backpressures up to 5.0 MPa without an external drain line connected. Built-in internal check valves route localized cavity pressure directly to the low-pressure return line to protect the seal lip from blowout.

Application Areas:

• Modern Agricultural Machinery: Reel and header drives for combine harvesters, net-wrapping attachments for round balers, heavy fertilizer distribution spinners, and rotating harvesting brushes.

• Mobile Construction & Deck Machinery: Crawler track drive motors for compact excavators or drilling rigs, hydraulic winch line pullers for truck cranes, and marine mooring/capstan drives.

• Industrial Mixing & Recycling Systems: Primary rotational drives for heavy material agitators, commercial plastic shredders, and high-load waste-conveying flight augers on municipal sweepers.

Expert Maintenance Tips:

• Plumb an Independent Case Drain Line for Demanding Duty Cycles: Although the motor features a high-pressure shaft seal, connecting a dedicated case drain line from the central G 1/4 port straight back to the reservoir is highly recommended during rapid bi-directional cycling, high surge spikes, or series-connected motor setups. This keeps shaft cavity pressure minimal, extends seal life, and continuously flushes heat away from the roller bearings.

• Ensure Fluid Priming and Air Bleeding Before Operation: Prior to initial commissioning or after prolonged system shutdown, fill the motor cavity with clean, filtered hydraulic oil. Run the motor at low idle under zero load for 5 to 10 minutes to purge all trapped air pockets from the loop, preventing cavitation damage to the internal disc-valve interface.

• Maintain Strict Fluid Temperature and Viscosity Control: Orbital motors depend on stable oil viscosity to perform efficiently. Maintain an ideal working viscosity envelope of 37-73 $cSt$ and a continuous oil temperature between -30°C and +60°C. Excessive fluid temperatures thin the oil, causing a drop in volumetric efficiency that can manifest as erratic turning or a loss of torque at low speeds.