MS08-2-G25-R08-1720-5DEJM Poclain Radial Piston Motor

Product Overview

The MS08 series low-speed high-torque (LSHT) radial piston hydraulic motors are a core product line within the Poclain Hydraulics MS multipurpose motor platform. Featuring an advanced radial piston cam ring design combined with multi-action disc valve distribution technology, these motors deliver low sensitivity to pressure and temperature variations, automatic compensation of the distribution friction pair, and exceptional starting torque with smooth low-speed operation. The MS08 series is available in both Classic and HighFlow™ versions.

Designed to fully comply with Poclain MS08 series mounting and interface standards, this motor offers 100% direct interchangeability with original Poclain units—enabling plug-and-play replacement without any管路 modifications or adapter plates, significantly minimizing downtime and retrofit costs.

The MS series covers an ultra-wide displacement range from 172 cc/rev to 15,000 cc/rev, including MS02, MS05, MS08, MS11, MS18, MS25, MS35, MS50, MS83, MS125, and MS250. The MS08 series delivers up to 1,248 cc/rev maximum displacement and 41 kW maximum power, making it ideal for wheel motor and tool drive applications. This model MS08-2-G25-R08-1720-5DEJM features a dual displacement (2-speed) configuration, enabling displacement switching via control ports to achieve high/low-speed mode transitions for varying operating conditions. Every unit undergoes 100% factory testing under simulated real-world working conditions, validating pressure, flow, torque output, and performance characteristics before shipment—ensuring reliable operation from the very first start.

Model Code Interpretation:

MS08-2-G25-R08-1720-5DEJM

• MS – Series code: Radial piston hydraulic motor (multipurpose platform, 450 bar working pressure)

• 08 – Size code: 08 platform, max power 41 kW, max displacement 1,248 cc/rev

• 2 – Displacement type: Dual displacement (2-speed) configuration

• G25 – Displacement group code

• R08 – Mounting flange and shaft configuration

• 1720 – Specific displacement code (dual displacement configuration)

• 5DEJM – Brake and special options configuration code

Technical Specifications 

MS08-2-G25-R08-1720-5DEJM

• Model: MS08-2-G25-R08-1720-5DEJM

• Type: Radial piston hydraulic motor (LSHT)

• Series Maximum Displacement: 1,248 cc/rev (76.1 cu.in/rev)

• Displacement Range: 467 – 1,248 cc/rev

• Maximum Pressure (MS series): 450 bar (6,527 PSI)

• Maximum Torque: 7,945 N·m (5,859 lb-ft)

• Maximum Power: 41 kW (55 HP)

• Maximum Speed: 450 RPM

• Displacement Type: Dual displacement (2-speed)

• Brake Configuration: Service Brake (optional) / Parking Brake (optional)

• Anti-skid Option: Twin-Lock™ available (optional)

• Medium: Mineral oil, synthetic hydraulic oil

• Operating Temperature Range: -40°C to +80°C (standard seals)

MS Series Maximum Specifications by Size:

• MS02/MSE02: Max displacement 398 cc/rev, max power 22 kW

• MS05/MSE05: Max displacement 750 cc/rev, max power 50 kW

• MS08/MSE08: Max displacement 1,248 cc/rev, max power 41 kW

• MS11/MSE11: Max displacement 1,687 cc/rev, max power 50 kW

• MS18/MSE18: Max displacement 2,812 cc/rev, max power 70 kW

• MS25: Max displacement 3,006 cc/rev, max power 90 kW

• MS35: Max displacement 4,198 cc/rev, max power 110 kW

• MS50: Max displacement 6,011 cc/rev, max power 140 kW

• MS83: Max displacement 10,019 cc/rev, max power 200 kW

• MS125: Max displacement 15,000 cc/rev, max power 240 kW

Key Technical Advantages

1. 100% Direct Interchangeability – Zero Modification Required

The MS08 series is engineered to exact Poclain mounting and interface specifications, with identical dimensions, port locations, and shaft end configurations. End users can replace original units directly without any管路 modifications or adapter plates—transforming unplanned downtime into scheduled, rapid maintenance while significantly reducing spare parts procurement costs and equipment downtime losses.

2. Radial Piston Cam Ring Design – Superior Starting Torque and Low-Speed Performance

The advanced radial piston cam ring design, combined with multi-action disc valve distribution technology, delivers exceptional performance. The radial piston configuration enables the motor to generate enormous traction force directly on the output shaft, even at extremely low speeds (as low as 0.5 RPM) . The MS08 series offers low sensitivity to pressure and temperature variations with automatic compensation of the distribution friction pair. This design makes the MS08 series ideal for wheel drive and low-speed heavy-load applications.

3. Dual Displacement (2-Speed) Configuration – Flexible Adaptation to Operating Conditions

This model features a dual displacement (2-speed) configuration with displacement switching via control ports. The displacement ratio reaches 2:1, enabling high/low-speed mode transitions—adapting to the speed and torque requirements of mobile machinery under varying operating conditions. This eliminates the need for additional gear-shifting mechanisms, simplifying system architecture.

4. Modular Design with Flexible Multi-Function Configuration

The MS08 series features a modular design with selectable output modules, function modules, distribution modules, and brake modules based on actual requirements. Optional service brakes, parking brakes, and Twin-Lock™ anti-skid systems are available. The disc distribution module features automatic wear compensation, maintaining high volumetric efficiency over the long term.

5. High-Pressure Capability with Long-Life Bearing System

MS series operates at 450 bar working pressure—industry-leading pressure ratings in the radial piston motor class. The high-durability bearing design accommodates substantial external axial and radial loads. Reliable high-temperature shaft seals ensure long-term sealing performance under demanding operating conditions.

6. 100% Factory Testing Under Simulated Working Conditions

Every MS08 series unit undergoes rigorous factory testing under simulated real-world conditions, validating pressure, flow, torque output, volumetric efficiency, and thermal characteristics across the full operating range. Test media match actual operating conditions, ensuring each unit is ready for immediate installation and reliable operation upon delivery—eliminating the risk of “dead on arrival” components.

Application Areas

The MS08 series motors are widely deployed across the following industries and equipment types:

• Construction Equipment: Excavator travel drives, skid steer loader wheel drives

• Road Construction: Roller travel drives, road maintenance equipment

• Material Handling: Forklifts, port cranes, handling equipment

• Agricultural Machinery: Combine harvester travel drives, self-propelled sprayers

• Mining Equipment: Mining machinery

• Railway Equipment: Railway engineering machinery

• Marine & Shipbuilding: Marine winches, deck machinery

• Industrial Equipment: Industrial tool drives, conveyors

Expert Maintenance Tips

1. Hydraulic Fluid Cleanliness Management

The MS08 series utilizes radial piston designs with minimal clearances between pistons and cylinder bores, making them highly sensitive to fluid contamination. It is recommended to install filters with ≤10μm filtration rating, maintaining fluid cleanliness to ISO 4406 19/17/14 or better. Never use degraded or substandard hydraulic fluids.

2. Air Bleeding Before Start-up

Always bleed air from the motor housing via the highest bleed screw before initial start-up or after extended shutdown periods to prevent cavitation damage. Use a waste oil collector to recover hydraulic fluid escaping during the filling process.

3. Case Drain and Backpressure Control

Ensure the case drain line is unrestricted with no flow restrictions. Shaft seal withstands 5 bar pressure. Excessive case backpressure will cause shaft seal damage and premature bearing failure. The drain line should return directly to the reservoir, not in parallel with the return line.

4. Rotation Direction Confirmation

Reversing the fluid flow direction will reverse the motor’s direction of rotation. Verify that the system circuit direction matches the required rotation direction before installation.

5. Dual Displacement Configuration Tuning

This model features dual displacement (2-speed) configuration with displacement switching via control ports. During commissioning, verify that the switching control pressure is stable and response is rapid. Avoid frequent switching under load to prevent shock loads.

6. Brake System Inspection

This series offers optional multi-disc service brakes and parking brakes. Before first use, verify that brake pressure settings are correct and the brake releases fully to avoid abnormal wear from starting with the brake engaged.

7. Coupling Alignment Requirements

Maintain shaft alignment within 0.05 mm concentricity and 0.5° angular deviation between the drive shaft and the load shaft. Excessive misalignment will lead to premature bearing wear and shaft seal leakage.

8. Periodic Inspection and Maintenance

Inspect shaft seals for leakage and listen for abnormal operating noise every 1,000 operating hours or every 6 months (whichever comes first). If reduced torque output or abnormal operating noise is observed, timely overhaul of the piston assembly and valve plate is recommended.