MR2800I-N1N1N1N1N0500/58037 Parker Radial Piston Motor 2792cc

Product Overview

The MR2800I-N1N1N1N1N0500/58037 is a low-speed high-torque radial piston fixed displacement motor built on the Parker/Denison/Calzoni MR series platform, in the MR2800I displacement size (2,792 cm³/rev). The motor employs Parker’s unique Fluid Column technology, where a pressurized oil column transmits piston force directly to the rotating shaft, eliminating the connecting rods, pistons, shims, and pin joints found in conventional radial piston motors, fundamentally reducing friction and leakage paths.

The MR series motor is available in 10 different frame sizes, corresponding to 39 standard displacements ranging from 75 to 9,000 cm³/rev. The MR2800I is a large frame size within this series, with a displacement of 2,792 cm³/rev, continuous working pressure of 250 bar, intermittent pressure of 300 bar, peak pressure of 420 bar, minimum smooth operating speed of 0.5 rpm, maximum speed of 215 rpm, and a weight of approximately 322 kg.

The MR2800I-N1N1N1N1N0500/58037 features a 335 h7 mounting flange, DIN 5463 male splined shaft, six-bolt connection, and optional Viton® seals. This model shares identical mounting flange and shaft dimensions with other MR2800I configurations (such as MR2800I-P1N1N1N1N0500/58152 and MR2800I-N1N1V1C1N0500/58589), differing only in seal material, port configuration, or rotation code.

Engineered as a form-fit-function replacement for original Parker/Calzoni MR2800I series motors, this model maintains identical mounting flange dimensions, shaft specifications, and port locations, enabling drop-in interchangeability without modification to the host machine’s mounting interface or hydraulic circuit. Each unit undergoes 100% simulated load testing prior to shipment, validating output torque and volumetric efficiency against original specifications.

Technical Specifications 

• Model: MR2800I-N1N1N1N1N0500/58037

• Reference Number: 358037 (Hydrola system)

• Original Brand: Parker / Denison / Calzoni

• Series: MR Series Radial Piston Fixed Displacement Motor

• Motor Type: Fixed displacement radial piston motor

• Design Feature: Five-piston design, Fluid Column technology, fixed displacement

• Displacement: 2,792 cm³/rev (170.4 in³/rev)

• Continuous Working Pressure: 250 bar (25 MPa / 3,625 psi)

• Intermittent Working Pressure: 300 bar (30 MPa / 4,351 psi)

• Peak Pressure: 420 bar (42 MPa / 6,092 psi)

• Minimum Smooth Operating Speed: 0.5 rpm

• Maximum Speed: 215 rpm

• Mechanical Efficiency: Up to 96%

• Volumetric Efficiency: Up to 99%

• Starting Torque: Up to 95% of theoretical value

• Mounting Flange: 335 h7

• Shaft Type: DIN 5463 male spline

• Connection Type: Six-bolt connection

• Seal Material: Viton® (optional)

• Rotation: Clockwise (standard configuration)

• Weight (approx.): 322 kg (710 lb)

• Hydraulic Fluid: Mineral-based; fire-resistant fluids (confirm seal compatibility)

• Circuit: Open circuit / Closed circuit

Key Technical Advantages

1. Fluid Column Technology — Eliminating Wear Paths by Design

The core technology of the MR2800I is Parker’s unique Fluid Column technology. Conventional radial piston motors transmit piston force to the crankshaft through connecting rods, pistons, shims, and pin joints — components that inevitably generate friction, clearance, and wear during high-frequency reciprocating motion. The MR series fundamentally eliminates these connecting components: the pressurized oil column itself becomes the force transmission medium, with cylinders performing only linear extension and retraction, transmitting force directly to spherical pairs on the rotating shaft. This design eliminates the friction and clearance issues inherent to linkage mechanisms, maintaining high mechanical efficiency across the full speed range.

2. 0.5 rpm Ultra-Low Speed Smooth Operation and Positioning Accuracy

Thanks to Fluid Column technology and the balanced-force design of the opposed five-piston layout, the MR2800I operates smoothly at speeds as low as 0.5 rpm, without stick-slip or speed fluctuation. This characteristic is critical for applications requiring precise positioning and stable low-speed operation — winch constant-tension control, injection molding screw drives, and jack-up systems demand stable torque output even at extremely low speeds. Starting torque reaches up to 95% of the theoretical value, preventing torque drop-off during heavy-load starting.

3. High Mechanical Efficiency and Long Service Life

The MR series motor achieves mechanical efficiency up to 96% and volumetric efficiency up to 99%. The high volumetric efficiency stems from the Fluid Column sealing principle: the spherical pair between the piston and cylinder head, and between the cylinder head and rotating shaft, forms two precision sealing interfaces, with pressure oil performing only linear motion within the extending/retracting cylinder — far fewer leakage paths than conventional designs. Fluid Column technology also gives the motor excellent thermal shock resistance, maintaining sealing performance during rapid oil temperature changes.

4. Modular Series with Broad Application Adaptability

The MR series offers 39 standard displacements from 75 to 9,000 cm³/rev, covering needs from compact to ultra-large sizes. The MR2800I is a large frame size within this series, sharing mounting interfaces and design architecture with models such as the MR2400I and MR3600L, enabling machine manufacturers to flexibly match displacement requirements. The MR series supports motor/pump reversible operation, is available with a full range of parking brakes, and suits winches, injection molding machines, mooring (constant tensioning), steerable thrusters, shredders, slew drives, and various other applications.

Application Areas

• Winches & Lifting Equipment: Heavy-duty winch drives, constant-tension mooring systems, offshore platform jacking systems

• Injection Molding & Die Casting: Injection molding screw drives, die casting clamping drives

• Marine & Offshore: Steerable thrusters, deck machinery, windlasses

• Material Processing & Recycling: Shredders (recycling industry), crusher drives

• Slew Drive Systems: Excavator swing, crane swing, stacker/reclaimer swing

• Industrial Heavy-Duty Drives: Various heavy-duty rotary or linear drive scenarios requiring ultra-low speed smooth operation and high starting torque

Expert Maintenance Tips

1. Mounting Alignment Requirements: The MR2800I features a six-bolt connection and DIN 5463 male splined shaft. During installation, ensure the coaxiality deviation between the motor shaft and drive-end spline does not exceed 0.05 mm. Spline mating surfaces must be clean and free of burrs, coated with appropriate grease to prevent corrosion. Tighten flange bolts diagonally to the specified torque.

2. Case Drain Management: The case drain port must be connected separately to the reservoir, with return lines below the minimum oil level. Back pressure should not exceed 0.5 MPa; higher back pressure will damage the shaft seal and deform the housing. In systems with multiple motors in series, ensure upstream component return back pressure does not exceed this limit.

3. Oil Preparation for Ultra-Low Speed Operation: The MR2800I can operate at 0.5 rpm, but this condition demands higher oil viscosity and cleanliness. ISO VG46 anti-wear hydraulic oil is recommended, with fluid cleanliness maintained at ISO 18/15 or NAS Level 9 or better. Before ultra-low speed operation, ensure the system is fully warmed up with oil temperature no lower than 20°C.

4. Fluid Column Technology Maintenance Characteristics: Fluid Column technology eliminates conventional piston motor linkage and pin components, shifting maintenance focus to spherical sealing pairs. If volumetric efficiency drops or case drain leakage increases, inspect the piston-cylinder head spherical pair and cylinder head-rotating shaft spherical pair sealing condition. Inspect case drain leakage every 1,000 operating hours; normal leakage should remain below 2 L/min.

5. Restart After Extended Storage: For motors stored over 6 months, manually rotate the shaft 2–3 revolutions to confirm free rotation before restart. Run at low pressure (5 MPa) under no load for 10 minutes, confirming normal case temperature and leakage before gradually applying load.