Rexroth MR Series Radial Piston Motor | MR1100 MR1800 MR4500 MR7000 | Hydraulic High Torque Motor

The MR Series (including MR1800H N1N1N1N) radial piston motors, manufactured by Chengyuan Hydraulic, are high-torque, low-speed (HTLS) power units engineered to the exact standards of the Bosch Rexroth MR Series. These motors are designed for heavy-duty applications where high starting torque and smooth operation at low speeds are critical. Chengyuan guarantees 100% drop-in interchangeability, matching all original mounting interfaces, shaft extensions, and port configurations. Every motor undergoes a rigorous 100% simulation load test on our digital benches to ensure volumetric efficiency and mechanical integrity that rivals original brand performance.

Technical Specifications 

• Compatible Brand: Bosch Rexroth (MR Series)

• Core Model Codes: MR1100, MR1600, MR1800, MR2400, MR2800, MR3600, MR4500, MR6500, MR7000

• Displacement Range: 1126 cc/rev to 7103 cc/rev

• Rated Pressure: 250 bar (25 MPa)

• Peak Pressure: 400 bar (40 MPa)

• Max Speed: 100 – 300 rpm (depending on frame size)

• Starting Torque Efficiency: ≥ 90%

• Displacement Type: Fixed Displacement

• Specific Configuration: MR1800H N1N1N1N (High-pressure H-series)

Key Technical Advantages:

• Superior Low-Speed Stability: The radial piston configuration combined with precision timing plate technology eliminates “cogging” at low speeds, ensuring smooth torque output even at speeds as low as 1 rpm.

• High Volumetric Efficiency: Utilizing high-strength ductile iron cylinders and precision-ground pistons, our motors minimize internal leakage, maintaining overall efficiency above 90% under rated conditions.

• Heavy-Duty Bearing Design: Integrated heavy-duty tapered roller bearings allow the motor to withstand significant radial and axial loads from the driven equipment, extending the service life in harsh environments.

• Advanced Sealing System: Equipped with premium-grade composite seals, the motor exhibits exceptional resistance to high case pressures and thermal aging, ensuring long-term leak-free operation.

Application Areas:

• Injection Molding Machines: Powering screw rotation for precise plasticizing torque.

• Marine & Deck Machinery: Ideal for winches, crane hoists, and capstan systems.

• Mining & Construction: Driving cutter heads on TBMs (Tunnel Boring Machines), heavy crushers, and drilling rigs.

• Material Handling: Driving large conveyor belts and heavy-duty rotary tables.

Expert Maintenance Tips:

• Case Drain Management: The drain line must be connected directly to the tank (not to the return line) and the case must be filled with oil before startup to ensure proper lubrication and cooling of internal components.

• Fluid Viscosity & Temperature: Use ISO VG 46/68 anti-wear hydraulic oil. Maintain operating temperatures between 30°C – 60°C and ensure oil cleanliness stays within NAS Class 9.

• Commissioning Protocol: After installation, run the motor at no-load for 15-30 minutes, gradually increasing the load. This ensures all air is bled from the system, preventing cavitation damage to the piston surfaces.