Poclain MK Series Radial Piston Motor | MK47 MK35 MK18 Low Noise Hydraulic Drive

The MK Series radial piston motors (including MK18, MK35, and MK47 models) by Chengyuan Hydraulic are premium high-pressure, Low-Speed High-Torque (LSHT) drive units engineered to be fully compatible with Poclain Hydraulics standards. Utilizing the classic multi-stroke radial piston architecture, these motors deliver exceptionally smooth power output via a precision-engineered cam-lobe curve. For specific models like MK47-2-A21, MK35-2-121, and MK18-1-D21, we have optimized the friction characteristics of the distribution plates and roller sub-assemblies. Every motor undergoes 100% simulated load testing before dispatch to ensure starting torque and volumetric efficiency meet original standards, guaranteeing 100% original-place interchangeability for heavy-duty construction, marine, and mining equipment.

Technical Specifications :

• Model Variants: MK18-1-D21 / MK35-2-121 / MK47-2-A21

• Displacement Range: 1058 $cm^3/rev$ (MK18) to 6000 $cm^3/rev$ (MK47)

• Rated Operating Pressure: 320 bar (32 MPa)

• Intermittent Peak Pressure: 450 bar (45 MPa)

• Rated Output Torque: 5000 N·m to 28000 N·m (model dependent)

• Maximum Peak Torque: Up to 35,000 N·m (under extreme duty)

• Speed Range: 0 – 150 rpm (optimized for high torque at low speed)

• Maximum Power Output: 70 kW to 150 kW

• Control Type: Fixed Displacement (Standard) / Dual-Displacement (Optional)

• Net Weight: Approx. 95 kg (MK18) to 280 kg (MK47)

Key Technical Advantages:

• Multi-Stroke Cam Lobe Technology: The internal cam ring features a multi-lobe curve that allows pistons to stroke multiple times per revolution. This dramatically increases power density and ensures high torque stability at ultra-low speeds, eliminating jerky “crawling” motions.

• Ultra-Low Noise Signature: By optimizing the roller-to-track geometry and employing a symmetrical piston layout, the motor cancels internal radial forces. This reduces structural vibration caused by hydraulic pulses, resulting in a noise level more than 15% lower than conventional motors.

• Hydrostatic Balanced Distribution: The flat axial distribution plate technology features automatic wear compensation. This minimizes internal leakage while drastically reducing starting friction, ensuring excellent cold-start performance and high volumetric efficiency.

• Reinforced Bearings and Seals: Heavy-duty tapered roller bearings allow for massive radial and axial load capacities, making these motors ideal for direct-wheel or hub-drive applications. Combined with premium high-pressure seals, they ensure leak-free operation even under high back-pressure conditions.

Application Areas:

• Construction & Road Machinery: Crawler excavator drives, vibratory rollers, and skid steer loaders.

• Marine & Port Equipment: Heavy-duty winches, capstan drives, and slewing mechanisms for cranes.

• Mining Machinery: Cutter head drives for roadheaders and heavy-duty conveyor drives.

Expert Maintenance Tips:

• Mandatory Pre-filling: Prior to the initial startup, always fill the motor housing with clean hydraulic oil through the highest drain port to prevent dry friction damage to the pistons and cam ring.

• Drain Line Back-pressure: The drain line must be connected directly to the reservoir. Back-pressure should strictly not exceed 2 bar, as excessive case pressure will cause shaft seal failure.

• Oil Cleanliness Standard: Maintain a system cleanliness level of at least ISO 4406 19/16/13 (NAS 7). Regular fluid analysis is recommended to protect the precision-ground cam surfaces from abrasive wear.