HMS18-B-C21-F19-1220 Poclain Radial Piston Motor 1501cc

Product Overview

The HMS18-B-C21-F19-1220-25DJM is a mid-large displacement radial piston hydraulic motor from the Poclain Hydraulics MS18/MSE18 multipurpose motor series, HMS18 frame size. The motor employs a radial piston cam-lobe design, in which working cylinders are arranged radially around a crankshaft, delivering high torque at low speeds. The MS18/MSE18 series offers a maximum displacement of 2812 cc/rev, maximum power of 70 kW, maximum working pressure of 450 bar (6,527 PSI), and maximum speed of 170 rpm. The HMS18, as a derivative of the MS18 series, employs the same radial piston design principle with rated pressure of 25 MPa and maximum pressure of 31.5 MPa.

The model code decodes as: “HMS18” = MS18 frame derivative series, “B” = displacement group code (corresponding to configurations within the 1501–1745 cm³/rev range), “C21” = control and distribution configuration, “F19” = F19 wheel flange mounting (flange diameter 98 mm), “1220” = port and mounting interface configuration code, “25DJM” = additional function and seal/brake configuration code.

The MS18/MSE18 series features a modular architecture comprising four major modules: output module (output shaft, flange, bearings), function module (pistons, cam ring), distribution module (valve plate, valve block), and brake module (parking/service brake). Each module can be independently configured and replaced. The MS18 series employs an internal curve radial piston design with a five-piston configuration for low-excitation-frequency operation, featuring low noise, high starting torque, and excellent low-speed stability.

The MS18/MSE18 series is widely compatible with 3.5–5 ton excavator travel drive systems, as well as marine winches, port lifting equipment, mining machinery, agricultural machinery, and other heavy-duty drive applications. The motor offers complete interchangeability: mounting flange, output shaft, and port configuration are identical to the original Poclain specification. Every unit undergoes 100% simulated duty-cycle testing before shipment.

Series-Related Models: The Poclain MS multipurpose motor series spans 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 1248 cc/rev, max power 41 kW), MS11/MSE11 (max displacement 1687 cc/rev, max power 50 kW), MS18/MSE18 (max displacement 2812 cc/rev, max power 70 kW), MS25 (max displacement 3006 cc/rev, max power 90 kW), MS35 (max displacement 4198 cc/rev, max power 110 kW), MS50 (max displacement 6011 cc/rev, max power 140 kW), MS83 (max displacement 10019 cc/rev, max power 200 kW), and MS125 (max displacement 15000 cc/rev, max power 240 kW). The MSE series is the frame variant with integrated brake.

Technical Specifications 

HMS18-B-C21-F19-1220-25DJM (Primary Model)

• Model: HMS18-B-C21-F19-1220-25DJM

• Brand Series: Poclain Hydraulics MS18 / MSE18 Derivative Series

• Motor Type: Radial piston, internal curve cam-lobe design, low-speed high-torque

• Displacement Group: B (corresponding to approx. 1501–1745 cm³/rev)

• Displacement Range (HMS18 Series): 1091–2812 cm³/rev

• Rated Pressure: 25 MPa (250 bar)

• Maximum Pressure: 31.5 MPa (315 bar)

• Series Maximum Pressure (MS18/MSE18): 450 bar (6,527 PSI)

• Maximum Speed (MS18/MSE18 Series): 170 rpm

• Theoretical Torque (@10 MPa, 1501 displacement group): Approx. 2387 N·m

• Rated Torque (@25 MPa, 1501 displacement group): Approx. 3580 N·m

• Maximum Torque (@31.5 MPa, 1501 displacement group): Approx. 4420 N·m

• Maximum Power: 70 kW (94 HP, standard displacement)

• Mounting Flange: F19 wheel flange (flange diameter 98 mm)

• Mounting Configuration Code: 1220

• Additional Configuration Code: 25DJM

• Rotary Group Inertia: 0.2 kg·m²

• Modular Design: Output, function, distribution, and brake modules

• Brake Options: Optional multi-disc parking brake / service brake

• Anti-Skid Feature: Optional TwinLock™ integrated anti-skid system

• Speed Sensor: Optional (T4/TR/TD type)

• Operating Temperature Range: -20°C to +80°C (reference: MS series general data)

MS18/MSE18 Series Displacement Specifications (Series Reference)

• Displacement 1091 cm³/rev (Group 6): Theoretical torque @10MPa 1735 N·m, rated speed 100 rpm, speed range 0–170 rpm

• Displacement 1395 cm³/rev (Group 8): Theoretical torque @10MPa 2218 N·m, rated speed 100 rpm, speed range 0–155 rpm

• Displacement 1571 cm³/rev (Group 9): Theoretical torque @10MPa 2498 N·m, rated speed 100 rpm, speed range 0–140 rpm

• Displacement 1747 cm³/rev (Group 0): Theoretical torque @10MPa 2778 N·m, rated speed 80 rpm, speed range 0–125 rpm

• Displacement 1911 cm³/rev (Group 1): Theoretical torque @10MPa 3038 N·m, rated speed 80 rpm, speed range 0–115 rpm

• Displacement 2099 cm³/rev (Group 2): Theoretical torque @10MPa 3337 N·m, rated speed 80 rpm, speed range 0–110 rpm

• Displacement 2340 cm³/rev (Group 0): Theoretical torque @10MPa 3721 N·m, rated speed 63 rpm, speed range 0–90 rpm

• Displacement 2560 cm³/rev (Group 1): Theoretical torque @10MPa 4070 N·m, rated speed 63 rpm, speed range 0–85 rpm

• Displacement 2812 cm³/rev (Group 2): Theoretical torque @10MPa 4471 N·m, rated speed 63 rpm, speed range 0–75 rpm

Note: MS18/MSE18 series parameters are compiled from Poclain official technical documentation and publicly available supplier technical data.

Poclain MS Series Other Frame Sizes (Series Reference)

• MS02/MSE02: Max displacement 398 cc/rev, max power 22 kW, max pressure 450 bar

• MS05/MSE05: Max displacement 750 cc/rev, max power 50 kW, max pressure 450 bar

• MS08/MSE08: Max displacement 1248 cc/rev, max power 41 kW, max pressure 450 bar

• MS11/MSE11: Max displacement 1687 cc/rev, max power 50 kW, max pressure 450 bar

• MS18/MSE18: Max displacement 2812 cc/rev, max power 70 kW, max pressure 450 bar

• MS25: Max displacement 3006 cc/rev, max power 90 kW

• MS35: Max displacement 4198 cc/rev, max power 110 kW

• MS50: Max displacement 6011 cc/rev, max power 140 kW

Key Technical Advantages

① Radial Piston Internal Curve Design — Low-Speed High Torque with Wide High-Efficiency Range

The HMS18-B-C21-F19-1220-25DJM utilizes Poclain‘s tried and tested radial piston cam design, which is continually being improved. Working cylinders arranged radially around a crankshaft deliver high torque at extremely low speeds (minimum 0.5–1 rpm) without requiring reduction gearing. Poclain official documentation states that MS series motors are “highly efficient at any speed or operating pressure, operating reliably in demanding applications across construction, material handling, agriculture, mining, railway, and marine industries.”For wheel-drive or tool-drive applications, this design simplifies the transmission chain while maintaining high torque output, reducing system complexity.

② Modular Architecture — Flexible Configuration and Simplified Maintenance

The MS18/MSE18 motor features a modular design concept comprising output, function, distribution, and brake modules. Each module can be independently removed and replaced; field service requires only the failed module to be replaced rather than a complete motor teardown, dramatically reducing machine downtime. The output module employs biconical roller bearings capable of withstanding strong radial and axial combined loads. The modular architecture also enables customers to flexibly specify brake presence, shaft type, and port orientation, reducing spare parts inventory complexity and maintenance costs.

③ F19 Wheel Flange Configuration — Compact Installation with High Load Capacity

The HMS18-B-C21-F19-1220-25DJM features an F19 wheel flange mounting configuration with flange diameter of 98 mm. The F19 flange is a standard Poclain wheel-mount interface that enables direct integration into wheel hubs or tool drive shafts, significantly reducing overall drivetrain dimensions. The standardized F19 flange mounting dimensions allow direct replacement of equivalent Poclain original motors, compatible with 3.5–5 ton excavator travel drive systems, marine winches, port lifting equipment, and other applications.

④ Integrated Brake System and TwinLock™ Anti-Skid Function

The MS18/MSE18 series offers multiple integrated brake options including emergency brake, service brake, and parking brake. The negative-type multi-disc parking brake works in conjunction with the motor’s distribution module, automatically engaging at stop and releasing at start, and engaging automatically in the event of hydraulic pressure loss or failure to prevent rollback on slopes. The MS18 series also offers the optional Poclain-patented TwinLock™ integrated anti-skid system, which automatically distributes flow between the two displacement chambers of the two-speed motor; when one wheel loses traction, the system transfers torque to the wheel with grip, significantly improving vehicle mobility on low-traction surfaces such as mud, sand, or slopes.

⑤ Broad Interchange Compatibility and Series Selection

The HMS18-B-C21-F19-1220-25DJM‘s standardized mounting interface (F19 wheel flange) allows direct replacement of equivalent Poclain original motors. The MS18/MSE18 series offers complete displacement coverage from 1091 cc/rev to 2812 cc/rev, enabling users to precisely select displacement size based on specific application torque, speed, and flow requirements. Standardized interface design maintains mounting compatibility across different displacement sizes within the same series, facilitating equipment upgrades or displacement adjustments. The series is widely compatible with 3.5–5 ton excavators, marine winches, port lifting equipment, mining machinery, and other heavy-duty drive applications.

Application Areas

• Excavator Travel Drives: 3.5–5 ton excavators, mini tracked excavators, compact wheeled excavators

• Marine & Offshore: Deck machinery, mooring winches, windlasses, hatch cover drives

• Port Lifting Equipment: Port crane slew and hoist mechanisms, grab drives, handling machinery

• Mining Machinery: Coal mine drills, underground LHDs, heavy-duty haulage vehicles

• Construction Equipment: Skid steer loaders, compact loaders, road roller travel drives

• Agricultural Machinery: Mini farming vehicles, ditchers, tractor drives

• Material Handling: Forklifts, telehandlers, grab drives

• Industrial Applications: Hydraulic transmission systems requiring low-speed high-torque direct drive

Expert Maintenance Tips

Pre-Installation Inspection: Verify flatness and cleanliness of the F19 wheel flange mating surface; check thread condition of mounting bolt holes. For wheel-mount (1220 configuration) applications, ensure wheel hub-to-output flange coaxiality within 0.05 mm; excessive misalignment causes bearing edge loading and premature seal wear. The splined output shaft-to-drive wheel fit should be free of interference. Use bolts of strength class 8.8 or higher, tightened in diagonal sequence to specified torque.

First Commissioning: The motor casing must be filled with clean hydraulic oil before initial start-up. Poclain official technical documentation explicitly states: “Very important: Fill the motor body with oil through its drain port before start-up.”Fill through the highest casing port until oil overflows from the level port. Dry starting causes metal-to-metal contact between piston-to-cam ring surfaces and the valve plate without lubrication, resulting in irreversible damage. For MS18 models equipped with integrated brakes, confirm the brake circuit has been properly bled to avoid delayed brake release.

Fluid Cleanliness: Maintain system oil cleanliness at NAS 8 (ISO 4406 18/16/13) or better. The radial piston motor’s valve plate and piston pairs are sensitive to particulate contamination; excessive contamination accelerates wear and causes volumetric efficiency degradation. Inspect return filter elements regularly and replace per the machine manufacturer‘s recommended interval. The MS18/MSE18 series is compatible with mineral oil, biodegradable hydraulic fluids, and other fluid types.

Scheduled Inspection: Check casing drain flow and brake clearance every 500 operating hours. Under normal conditions, drain flow should remain stable; a sustained increase indicates accelerated wear of piston pairs or valve plate surfaces, and preventive maintenance should be scheduled. Inspect the output flange area for oil seepage; replace seals at the first sign of degradation. For marine winch and port lifting applications, pay particular attention to motor operation under heavy loads and frequent start-stop conditions.

Long-Term Storage Protection: If the motor will be idle for more than 3 months, fill the casing with rust-preventive hydraulic oil and manually rotate the shaft several turns monthly to prevent corrosion or adhesion on piston-to-cam ring interfaces and valve plate surfaces. Perform a no-load run-in before returning to service.