MS18-2-121-A18 Poclain Motor | 450 Bar 2099cc Radial Piston

Product Overview

The MS18-2-121-A18-1330-00-MR is a dual-displacement radial piston hydraulic motor from Poclain Hydraulics’ MS/MSE18 series, featuring a full displacement of 2099 cc/rev and a half displacement of 1049 cc/rev. The MS/MSE18 series is the large frame offering in Poclain’s multi-purpose motor line, covering displacements from 1091 to 2812 cc/rev with up to 70 kW (94 HP) power, 17,900 N·m (13,202 lb-ft) maximum torque and 450 bar (MS version) / 400 bar (MSE version) maximum pressure, with a multi-speed concept reaching up to 170 rpm.

The MS/MSE18 series employs a modular design concept allowing a single base motor to be configured with different displacement groups, flow-distribution modules, brake modules and output-end modules for wheel-drive or shaft-drive installation. Primary applications include construction equipment, material handling, agriculture, environment, mining, rail, marine and industry. The MS18 series features 100% interchangeable interfaces with original Poclain motors, widely deployed in road rollers, wheeled excavators, scrapers and mining equipment.

The series is built on a tried and tested radial piston cam design that is continually being improved, delivering high efficiency at any speed or operating pressure and making a major contribution to machine energy efficiency. Optimized through thousands of hours of development and testing, MS series motors withstand the most extreme operating conditions while requiring very little maintenance, reducing machine downtime and optimizing productivity.

The model code breaks down as follows: MS18 identifies the MS series 18 frame size; 2 denotes displacement group 2 (2099/1049 cc/rev dual displacement); 121 is the flow-distribution/function module code (1=valving type, 2=lug fixing, 1=standard configuration); A18 is the shaft and mounting configuration code (wheel flange mounting, 8×Ø22 on Ø275); 1330 is the additional option combination code; 00-MR denotes rotation direction and additional options.

Every unit undergoes 100% simulated operating-condition bench testing prior to shipment. Mounting flange, shaft end and port dimensions match the original Poclain MS18 series exactly, enabling true drop-in interchangeability with zero modification required.

Technical Specifications

MS18/MSE18 Series Frame Size Specifications:

• MS18-8: Full displacement 1395 ml/r, half displacement 697 ml/r, max power 62 kW, theoretical torque at 10 MPa 2085 N·m, rated torque 5212 N·m, rated pressure 25 MPa, max pressure 40 MPa, rated speed 55 rpm, speed range 0–150 rpm

• MS18-9: Full displacement 1571 ml/r, half displacement 785 ml/r, max power 62 kW, theoretical torque at 10 MPa 2348 N·m, rated torque 5870 N·m, rated pressure 25 MPa, max pressure 40 MPa, rated speed 55 rpm, speed range 0–150 rpm

• MS18-0: Full displacement 1747 ml/r, half displacement 873 ml/r, max power 62 kW, theoretical torque at 10 MPa 2611 N·m, rated torque 6528 N·m, rated pressure 25 MPa, max pressure 40 MPa, rated speed 55 rpm, speed range 0–150 rpm

• MS18-1: Full displacement 1911 ml/r, half displacement 955 ml/r, max power 62 kW, theoretical torque at 10 MPa 2856 N·m, rated torque 7140 N·m, rated pressure 25 MPa, max pressure 35 MPa, rated speed 55 rpm, speed range 0–135 rpm

• MS18-2 (This Model): Full displacement 2099 ml/r (128.0 cu.in/rev), half displacement 1049 ml/r (64.0 cu.in/rev), max power 62 kW (1C) / 42 kW (2C), theoretical torque at 10 MPa 3137 N·m, rated torque 7843 N·m, rated pressure 25 MPa, max pressure 35 MPa, rated speed 50 rpm, speed range 0–125 rpm

• MS18-6/8/9/0/1/2 (MSE18 Series): Full displacement 2340–2812 ml/r (142.7–171.6 cu.in/rev), max torque 6,680–7,945 N·m, max pressure 400 bar (MSE version), max speed 130 rpm, max power 41 kW (55 HP)

MS18/MSE18 Series Common Specifications:

• Series Max Displacement: 2812 cc/rev (171.6 cu.in/rev)

• Series Max Torque: 17,900 N·m (13,202 lb-ft)

• MS Series Max Working Pressure: 450 bar (6,527 psi)

• MSE Series Max Working Pressure: 400 bar (5,801 psi)

• Series Max Power: 70 kW (94 HP)

• Series Max Speed: 170 rpm

• Type: Radial piston LSHT hydraulic motor (internal curve cam ring design)

• Control: Single or dual displacement

• Brake: Service brake, parking brake and hydrostatic boosted brake options

• Motor Type: Wheel motor / shaft motor (modular)

• Anti-Skid Option: TwinLock™ integrated anti-skid available

• Motor Inertia: 0.2 kg·m²

• Displacement Range: 1091–2812 cc/rev

• Original Design: Poclain Hydraulics, France

MS18-2-121-A18-1330-00-MR Additional Specifications:

• Model Code: MS18-2-121-A18-1330-00-MR

• Type: Radial piston LSHT hydraulic motor, internal curve cam ring design

• Displacement: 2099 ml/r (128.0 cu.in/rev) full / 1049 ml/r (64.0 cu.in/rev) half

• Displacement Ratio: 2:1

• Rated Working Pressure: 25 MPa (250 bar)

• Max Working Pressure: 35 MPa (350 bar)

• Rated Torque: 7,843 N·m (5,784 lb-ft)

• Theoretical Torque at 10 MPa: 3,137 N·m (full displacement)

• Max Speed: 125 rpm (2C dual displacement)

• Rated Speed: 50 rpm

• Valving Type: Dual displacement valving module (121 code)

• Mounting Flange: Wheel flange mounting, 8×Ø22 on Ø275

• Shaft Configuration: Wheel flange output

• Brake Configuration: 1330 option configuration (parking brake optional)

• Anti-Skid Option: TwinLock™ available

• Motor Type: Wheel motor

• Operating Temperature Range: -40°C to +115°C

• Hydraulic Fluid: Mineral oil (ISO VG46/68), synthetic oil, water glycol

• Original Design: Poclain Hydraulics, France

MS18-9-121-A18-1120-0000 Additional Specifications (Same Series Reference):

• Model Code: MS18-9-121-A18-1120-0000

• Displacement: 1571 ml/r full / 785 ml/r half

• Theoretical Torque at 10 MPa: 2,348 N·m

• Rated Torque: 5,870 N·m

• Max Pressure: 40 MPa (400 bar)

• Rated Speed: 55 rpm

• Speed Range: 0–150 rpm

• Mounting Flange: Wheel flange mounting (A18 configuration)

• Manufacturer Part Number: 004643748C

Key Technical Advantages

1. Internal Curve Radial Piston Design for High Startup Torque and Smooth Low-Speed Operation

The MS18-2 employs Poclain’s patented internal curve radial piston design, with multiple pistons arranged radially around a cam ring to deliver high torque at extremely low speeds. With theoretical torque of 3,137 N·m at 10 MPa and rated torque of 7,843 N·m at full displacement, the motor operates smoothly across the 0–125 rpm speed range without stick-slip. High startup torque ensures reliable starting under load, making it ideal for wheel-drive and road roller vibration shaft applications.

2. Modular Architecture for Maximum Adaptability

The MS/MSE18 series employs Poclain’s modular design concept, allowing displacement group, flow-distribution module, brake module and output-end module to be reconfigured. The wheel flange mounting configuration (8×Ø22 on Ø275) supports wheel-drive mounting for road rollers, wheeled excavators, scrapers and mining equipment. Optional TwinLock™ integrated anti-skid provides differential locking via hydraulic control for improved traction on challenging terrain. Brake options include service brake, parking brake and hydrostatic boosted brake modules.

3. High-Precision Cam Ring and Long Service Life

The MS18-2 cam ring is manufactured from high-hardness alloy steel with precision grinding to resist high-frequency contact fatigue from piston rollers. A hydrodynamic oil film forms between rollers and cam ring, significantly reducing wear rate and extending overhaul intervals. The modular design allows replacement of individual worn modules rather than the entire motor, substantially reducing total cost of ownership. The motor features low noise, high radial load capacity and high starting torque.

4. High Radial Load Capacity and Hydrostatic Dynamic Braking

The MS/MSE18 series motors can withstand substantial axial and radial forces, with large diameter bearing support enabling direct handling of wheel or tool-end radial loads without additional bearing support mechanisms, simplifying drivetrain design. Hydrostatic dynamic braking is an inherent design feature of the motor, providing reliable dynamic braking without additional braking mechanisms.

5. 100% Simulated Load Testing & Drop-In Interchangeability

Each MS18-2-121-A18-1330-00-MR unit is bench-tested under simulated operating conditions prior to dispatch, covering pressure cycling, speed shifting and thermal variation. Mounting flange, shaft end and port dimensions match the original Poclain MS18 series exactly, enabling direct replacement without pipework or interface modification. Motor performance is very close to original Poclain motors, sometimes even superior, with both complete motors and spare parts 100% interchangeable.

Application Areas

The MS18/MSE18 series is widely deployed in heavy-duty travel and tool drives:

• Road Rollers: Hamm 4011 and similar vibratory roller wheel drives and vibration shaft drives

• Construction: wheeled excavator travel drives, scraper drives, rotary drill head drives, trenchers

• Agriculture: combine harvesters, self-propelled sprayers, cotton pickers

• Material Handling: heavy-duty forklifts, aerial work platforms, beam carriers

• Mining: roadheader star wheel drives, subsurface loaders, coal mining machinery travel drives

• Marine & Offshore: deck machinery, winch drives

• Industrial: shredders, industrial conveyors, mill drives

Expert Maintenance Tips

1. Dual Displacement Valving Module Maintenance: The dual displacement valving module is controlled by pilot pressure. If shift response is sluggish or excessively harsh, inspect the pilot control spool for sticking and the flow-distribution shaft O-rings for aging. Shift operations should be performed at low speed or standstill to avoid impact loading on the distribution mechanism. Inspect pilot control pressure and valving module seal condition every 1,000 hours.

2. Wheel Flange Mounting Surface Inspection: The MS18-2-121-A18 features wheel flange mounting (8×Ø22 on Ø275). Periodically inspect the output flange plane and wheel hub mating surface for wear or deformation. Ensure flange mating surface parallelism deviation does not exceed 0.05 mm during installation, and tighten bolts evenly in a diagonal sequence to Poclain technical manual torque values. Mounting surface flatness requirement is 0.2 mm with Ra 12.5 μm surface roughness.

3. Oil Cleanliness and Temperature Control: Maintain system oil cleanliness at ISO 4406 18/16/13 or better. HV46 hydraulic oil is recommended. Operating oil temperature should be kept below 80°C; elevated temperatures accelerate seal degradation. Replace hydraulic oil and filter after the first 500 hours, then follow a 2,000-hour or annual replacement cycle. Case drain temperature is affected by pressure and speed and is always higher than circuit temperature—system temperature must not exceed 115°C at any point.

4. Drain Line Management and Housing Priming: The drain port must return to the reservoir independently—housing back pressure must not exceed 2 bar. The drain line end must remain submerged to prevent air ingestion. Fill the housing with clean hydraulic oil before first startup. After extended shutdown, fill the housing again before restarting.

5. Periodic Piston Group and Cam Ring Inspection: As a radial piston motor, the MS18-2-121-A18’s primary wear points are the piston rollers and cam ring contact surface. Inspect piston roller wear and cam ring working surface every 2,000 hours. Both displacement cam surfaces require inspection. Abnormal noise or efficiency loss requires immediate shutdown and service. Use Poclain original specification parts when replacing piston groups to ensure fit accuracy and assembly torque per technical manual requirements.

6. Troubleshooting Guide: According to the Poclain MS18 official repair manual, common issues include abnormal noise, vibration and excessive internal leakage. Abnormal noise typically indicates worn bearing support requiring replacement; vibration may originate from loose fasteners or bearing wear; excessive internal leakage requires inspection of the distribution valve and piston group condition. Establish a regular inspection regime recording motor operating parameter trends to detect potential faults early.

7. Modular Repair Strategy: The MS/MSE18 series modular design allows replacement of individual worn modules rather than the entire motor. Establish a modular spare parts inventory including flow-distribution module seals, piston groups and cam rings to minimize machine downtime. When replacing modules, follow Poclain official technical manual torque values and assembly sequences.