MS18-1-121-A18 Poclain Two-Speed Motor 1911cc 450 bar

Product Overview

The MS18-1-121-A18-1320-5000 is a two-speed variable displacement model within the 18 frame size of Poclain Hydraulics’ MS Series multipurpose radial piston hydraulic motors, with a maximum displacement of 1911 cm³/rev. The MS Series is a direct drive hydraulic motor range ideal for wheel motor or tool drive applications, with displacements from 172 cc/rev to 15000 cc/rev, widely used in construction equipment, material handling, agricultural, environmental, mining, on rail, marine, and industrial sectors.

The MS18-MSE18 is one of the largest frame sizes in the MS Series, with maximum displacement of 2812 cc/rev, up to 70 kW maximum power, maximum torque of 17900 N·m, and maximum pressure of 450 bar. The motor features a modular design for flexible configuration across demanding applications, meeting all requirements of the most demanding markets. With multi-speed conception, maximum speed reaches 170 rpm.

Model code breakdown: MS18 = MS Series size 18; 1 = dual displacement configuration (2-Displacement); 121 = displacement code; A18 = mounting flange and port configuration; 1320 = shaft output and brake configuration; 5000 = variant suffix. The MS18 Series offers displacement options from 1091 cc/rev to 2812 cc/rev, covering both 1-displacement (single-speed) and 2-displacement (two-speed) configurations.

As a drop-in replacement, the motor is fully compatible with the OEM Poclain specification in mounting interface, port configuration, and performance characteristics, enabling direct replacement without hydraulic circuit or mounting bracket modification. Every unit undergoes 100% simulation-based testing prior to shipment, covering displacement calibration, torque output, pressure holding, and internal leakage.

Technical Specifications

All parameters below are based on Poclain Hydraulics official product technical documentation (801578116T) and verified supplier technical pages:

• Complete Model: MS18-1-121-A18-1320-5000

• Part Number: 999060 / 007043769V

• Brand: Poclain Hydraulics

• Product Series: MS Series multipurpose radial piston motor, MS18-MSE18 frame size

• Product Type: Two-speed variable radial piston motor, wheel/tool direct drive

• Max Displacement (Series): 2812 cm³/rev (171.6 cu.in/rev)

• This Model Displacement (MS18-1): 1911 cm³/rev (116.6 cu.in/rev)

• Half Displacement: 956 cm³/rev (58.3 cu.in/rev)

• Displacement Options (Series): 1091 / 1395 / 1571 / 1747 / 1911 / 2099 / 2340 / 2560 / 2812 cm³/rev

• Nominal Working Pressure: 400 bar (5802 PSI)

• Max Working Pressure: 450 bar (6527 PSI)

• Max Torque (Series): 17900 N·m (13202 lb-ft)

• This Model Theoretical Torque (@100 bar): 3038 N·m (1545 lb-ft)

• Max Power: 70 kW (94 HP)

• Max Speed (Max Displacement): 170 rpm

• Max Speed (Min Displacement): 315 rpm

• Drive Type: Radial piston cam design

• Mounting: Wheel mount / shaft mount

• Motor Type: Wheel motor / shaft motor

• Brake Type: Service brake / parking brake / hydrostatic boosted brake (optional)

• Anti-Skid Feature: TwinLock™ (optional)

• Hydraulic Fluid: Mineral oil-based hydraulic fluid

• Weight: Approx. 120 kg (115 – 160 kg with brake options)

• Application Markets: Construction equipment, material handling, agriculture, environment, mining, on rail, marine, industry

Note: Specifications are based on Poclain Hydraulics official product technical documentation (801578116T) and verified supplier technical pages (Radward, Howo Spare Parts, Hainzl, etc.). The MS18-1-121-A18-1320-5000 is the 1911 cm³/rev two-speed specification within the MS18 Series. The series features a modular design with model code options for displacement, mounting flange, brake, shaft output, and other configurations. Always verify against the complete model code and consult the latest Poclain official technical documentation during selection.

Key Technical Advantages

1. Radial Piston Cam Design for Ultra-Low-Speed High-Torque Direct Drive

The MS18 employs Poclain’s classic radial piston cam design, delivering low-speed, high-torque direct drive characteristics. This design enables the motor to output high torque directly at the wheel end or tool end without additional gearbox reduction, simplifying the transmission system structure. Poclain’s patented spherical control area and multi-roller guide structure enable the motor to maintain smooth output of full rated torque even at extremely low speeds of 1 RPM, completely eliminating the “crawling” or vibration phenomena often observed in conventional orbital motors. The MS Series motors exhibit stability, reliability, and compactness in roller applications, facilitating the direct propulsion of the rollers’ drums and obviating the necessity for a gearbox.

2. Two-Speed Variable Function for Wide Operating Range Adaptability

The MS18-1-121 features a dual displacement (2-Displacement) configuration, supporting both 1-displacement and 2-displacement valve block configurations. Utilizing a built-in electronically controlled pilot valve, it enables seamless switching between “high-torque, low-speed climbing” and “low-torque, high-speed travel” while the machine is in motion, providing greater operator comfort. Standard displacement configuration power is 70 kW at maximum displacement of 2812 cm³/rev with maximum speed of 170 rpm; half displacement configuration achieves maximum speed up to 315 rpm.

3. Modular Design for Flexible Configuration

The MS18 Series employs a modular design architecture, composed of torque displacement module, distributor module, brake/wheel mounting module, output shaft module, and other modules. Users can select different displacements, mounting flanges, brake types (service/parking/hydrostatic boosted), shaft output forms (wheel hub shaft/shaft motor), and other configurations based on specific application requirements. This modular design greatly enhances system integration flexibility and maintenance convenience.

4. Integrated Braking System and TwinLock™ Anti-Skid Function

The MS18 can be equipped with service, parking, and hydrostatic boosted brake functions, with the brake module integrated into the motor structure, ensuring safety during slope parking and emergency braking. Additionally, the optional TwinLock™ anti-skid function is available, with the solution available from MS02 to MS50 and MHP motor series, further enhancing equipment traction performance and safety on low-friction surfaces.

5. Heavy-Duty Bearings with High Radial Load Capacity

The motor is equipped with heavy-duty internal roller bearings, and the output flange directly withstands the substantial vehicle loads and lateral impact forces transmitted through the tires, making it ideal for mounting directly onto the wheel assembly as a “Wheel Motor.” While the F12 Series employs a 40° bent axis structure with heavy-duty cylindrical roller bearings rated for 1900 kg maximum radial shaft load, the MS18 further enhances radial and axial load capacity, adapting to the most demanding construction machinery travel conditions.

6. 100% Simulation-Based Testing and Drop-In Interchangeability

Every MS18-1-121 undergoes 100% simulation-based testing prior to shipment. Test protocols cover displacement calibration, torque output verification, pressure holding performance, and internal leakage detection. As a drop-in replacement, the motor is fully compatible with the OEM Poclain specification in mounting dimensions (A18 flange configuration), port layout (1320 shaft output and brake configuration), and performance characteristics, enabling direct replacement of the original motor. The product is widely used in SDLG and other brand rollers and graders for both OEM and aftermarket applications.

Application Areas

• Compactor Travel Drive: Travel motors for SDLG and other brand vibratory and pneumatic tire compactors — the most typical and primary application of the MS18

• Grader Assist Drive: Assist drive systems for SDLG G9220 and similar model graders, with VDF freewheeling valves for stable drive

• Construction Equipment Wheel Drive: Wheel drive systems for medium excavators, wheel loaders, and telehandlers

• Material Handling Equipment: Travel drives for large forklifts, stackers, and reach stackers

• Agricultural Machinery: Travel drive systems for large harvesters, self-propelled sprayers, and other agricultural equipment

• Environmental Equipment: Travel drives for garbage compactors and road cleaning vehicles

• Mining Equipment: Wheel drive motors for underground auxiliary transport vehicles and mining trucks

• Railway & Marine: Hydraulic drive systems for track maintenance equipment and marine deck machinery

Expert Maintenance Tips

Pre-Installation Checks:

• Verify mounting flange (A18 configuration) alignment with equipment mounting surface; ensure surface is clean and free of burrs

• Inspect port seals for damage and confirm compatibility with the hydraulic fluid in use

• The motor must be fully filled with clean hydraulic fluid via the housing drain port prior to installation to prevent dry friction damage to piston/cylinder during startup

• Confirm brake (if equipped) release pressure meets system requirements; verify TwinLock™ function (if equipped) is operational

Operational Maintenance:

• Use pressure filters with ≤ 10 μm filtration accuracy; maintain hydraulic oil cleanliness to required level

• Recommended fluid: mineral oil-based anti-wear hydraulic oil; replace filter elements and oil at regular intervals

• Periodically inspect motor exterior for leakage signs, focusing on shaft seal and port connections

• Periodically monitor motor operating temperature and noise level; abnormal increase may indicate internal wear or fluid contamination

• The motor’s drain line must run directly and independently to the hydraulic reservoir — connecting it in series with the system’s main return line is strictly prohibited! If the back pressure exceeds 5 bar, the main shaft oil seal will instantly deform, leak fluid, or even rupture

• Periodically check brake function and release pressure (if equipped); verify TwinLock™ anti-skid function is operational

• Two-speed shifting function should be tested periodically to confirm smooth, shock-free switching

Troubleshooting Guide:

• Motor fails to rotate or speed abnormal: Check hydraulic system supply pressure; verify directional valve and brake release are functioning properly; check oil cleanliness

• Insufficient output torque: Confirm system pressure reaches rated value (400 bar continuous / 450 bar intermittent); inspect cam ring and pistons for wear

• Abnormal noise or vibration: Check housing oil fill level; verify suction line is unobstructed; check mounting bolt tightness

• External leakage: Inspect shaft seal for aging or damage; verify drain line back pressure is within 5 bar

• Two-speed switching failure: Check two-speed switching control signal reaches the motor correctly; verify switching valve spool is not stuck

• Brake abnormality: Check brake release pressure; inspect brake friction plates for wear

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