Product Overview
The MK04-2-114-K04-3340-3000 is a high-performance compact radial piston hydraulic motor from the Poclain Hydraulics MK/MKD04 Series. The MK Series is a compact direct drive motor platform specifically developed for compactor wheel drive, with the MK04 frame size covering displacements from 272 to 408 cc/rev, maximum power of 18 kW (24 HP), maximum torque of 2,600 Nm, maximum pressure up to 400 bar, and high speeds reached at 120 rpm. Through its ultra-short structure, large diameter 4-contact roller bearing, and modular design, this series has been extensively validated in compactor drive applications, while also being suitable for mining, agriculture, environmental, and other markets.
The MK04-2-114-K04-3340-3000 belongs to the “2” displacement group within the MK04 frame size, featuring 408 cc/rev displacement in a single displacement configuration with integrated brake. Model code breakdown: MK04 designates the 04 frame size compact radial piston motor in the MK Series; 2 indicates the displacement group (408 cc/rev); 114 specifies the mounting flange and shaft configuration; K04 defines port location and connection specification; 3340 specifies the control and valve body configuration; and 3000 indicates the special option code (with brake configuration).
The motor is manufactured to original Poclain Hydraulics specifications with 100% drop-in interchangeability, requiring no modification to mounting interfaces, port positions, or hydraulic connections. Every unit undergoes 100% simulated operating condition testing at the factory, including rated pressure loading, volumetric efficiency verification, seal integrity assessment, and low-speed smoothness validation prior to shipment. This model is the original equipment motor for Bomag BW120 AD-3 and comparable compactor travel drive systems.
Technical Specifications
MK04-2-114-K04-3340-3000:
Series / Type: Poclain MK/MKD04 Series compact radial piston hydraulic motor
Displacement group: Displacement Group 2
Displacement: 408 cc/rev (24.9 cu.in/rev)
Design: Radial piston cam-lobe design, working cylinders radially arranged around crankshaft
Maximum working pressure: 400 bar (5,802 psi / 40 MPa)
Maximum torque: 2,600 Nm (1,918 lb-ft)
Theoretical torque at 100 bar: 649 Nm (330 lb-ft)
Maximum power: 18 kW (24 HP)
Maximum speed: 100–120 rpm
Direction of rotation: Bidirectional
Mounting: Wheel Motor or Shaft Motor
Bearing arrangement: Large diameter 4-contact roller bearing
Brake: Integrated parking brake
Minimum brake release pressure: 17 bar (246 PSI)
Motor inertia: 0.028 kg·m²
Mounting screws: 5 x M16 x 2, grade 12.9, tightening torque 355 Nm
Housing material: High-strength cast iron
Approximate weight: 31 kg
MK/MKD04 Series displacement range (for reference):
MK04-8: 272 cc/rev (16.6 cu.in/rev), theoretical torque 432 Nm, max speed 120 rpm
MK04-0: 340 cc/rev (20.7 cu.in/rev), theoretical torque 541 Nm, max speed 110 rpm
MK04-2: 408 cc/rev (24.9 cu.in/rev), theoretical torque 649 Nm, max speed 100 rpm
MKD04-0: 456 cc/rev (27.8 cu.in/rev), theoretical torque 725 Nm, max speed 90 rpm
MKD04-1: 502 cc/rev (30.6 cu.in/rev), theoretical torque 798 Nm, max speed 82 rpm
MKD04-2: 545 cc/rev (33.2 cu.in/rev), theoretical torque 867 Nm, max speed 75 rpm
Note: MK04 is the single displacement configuration; MKD04 is the larger displacement extended configuration. Working pressure is 400 bar for both. Displacement, pressure, torque, and speed data above are sourced from Poclain Hydraulics official technical brochures and selection guides. For precise technical specifications of the MK04-2-114-K04-3340-3000, always consult the official Poclain Hydraulics technical manual or the product nameplate data.
Key Technical Advantages
1. Ultra-Short Structure Design with Compact Direct Drive
The MK04 Series employs Poclain’s compact direct drive design with an extremely compact structure, ideally suited for wheel drive or tool drive applications. The ultra-short structure allows the motor to be installed directly within the compactor drum or wheel hub without additional reduction mechanisms or drive shafts, significantly simplifying drivetrain design. Output shaft bearings accommodate simultaneous radial and axial external loads, eliminating the need for separate bearing support housings and reducing installation costs and system complexity.
2. Radial Piston Cam-Lobe Principle for High Starting Torque
The MK04-2-114-K04-3340-3000 employs Poclain’s signature radial piston cam-lobe architecture, with working cylinders arranged radially around the crankshaft and pistons converting radial force into crankshaft rotational torque through the cam ring. Piston force is applied directly to the crankshaft eccentricity, maximizing the moment arm and enabling extremely high starting torque even at very low speeds. Starting torque is calculated at 85% of initial torque at given pressure, with high starting torque characteristics. The motor maintains smooth operation even at extremely low speeds without stick-slip phenomena, particularly suited to compactors requiring extremely low-speed uniform advancement during compaction operations.
3. Large Diameter 4-Contact Roller Bearing
The MK04 Series employs a large diameter 4-contact roller bearing, capable of simultaneously accommodating significant radial and axial external loads. The engineering advantage of this bearing configuration lies in its ability to directly absorb radial and axial forces generated by compactor drums without requiring a separate bearing support housing. Compared to conventional bearings, the 4-contact roller bearing offers higher load capacity and longer service life, performing particularly well under frequent start-stop and shock load conditions.
4. Integrated Parking Brake
The MK04-2-114-K04-3340-3000 is equipped with an integrated parking brake, with minimum release pressure of 17 bar (246 PSI). The brake operates on a spring-applied, hydraulically-released principle, automatically applying braking force upon loss of system pressure to ensure safe load holding during power failure or hydraulic system malfunction. For applications with stringent safety braking requirements such as compactors, this integrated design eliminates the need for a separately configured brake, simplifying system integration and reducing installation space requirements. Parking brake functionality is a standard option.
5. Optimized Specifically for Compactor Applications
The MK Series was developed specifically by Poclain for compactor wheel drive, with the MK04 achieving 408 cc/rev displacement capability and 2,600 Nm maximum torque output within its compact envelope. The engineering value of direct drive includes: elimination of gear transmission backlash and energy losses, improving transmission efficiency; reduced system complexity with fewer maintenance points; and greater machine architecture flexibility for manufacturers. The MK04 Series is widely applicable to wheel drive and tool drive systems across construction equipment, mining, agriculture, environmental, and other markets.
Application Areas
Road construction and maintenance: Vibratory roller wheel drives (Bomag BW120 AD-3 and comparable brands), the series is specifically developed for compaction equipment
Construction equipment: Mini rollers, walk-behind rollers, tandem drum roller travel drives
Mining equipment: Mining mini loaders, underground transport vehicle drives
Agricultural machinery: Mini tractor wheel drives, specialty agricultural equipment travel systems
Environmental equipment: Sanitation vehicle travel drives, street sweeper drives
Tool drives: Drill, milling, and cutting tool rotary drives
Material handling: Mini forklift travel drives, aerial work platform travel systems
Expert Maintenance Tips
1. Case Filling and Air Purging — The First Step Before Startup
The MK04-2-114-K04-3340-3000 must be filled with oil through its drain port before commissioning. Poclain technical manual specifically emphasizes: the motor body must be filled with oil through its drain port before startup. The MK04 radial piston architecture creates a complex internal case cavity geometry; starting an un-purged motor can cause dry friction damage between piston ball ends and the cam ring, leading to irreversible premature wear.
2. Fluid Cleanliness Management Is the Primary Task
The MK04 Series operates with micron-level clearances between radial pistons and the cam ring, and between pistons and cylinder bores. Particulate contamination in hydraulic fluid is the leading cause of piston scoring and cam ring wear. Systems must be equipped with filtration rated to ISO 4406 18/16/13 or better. In high-contamination environments such as compactor or construction job sites, consider increasing filtration to ISO 4406 17/15/12 and shortening filter replacement intervals to 500–800 hours.
3. Case Drain Line Configuration Requirements
Case drain from the MK04 motor must be routed to the reservoir through the highest drain port, with case pressure strictly controlled within specified limits. Excessive case pressure will cause shaft seal failure; insufficient pressure will reduce lubrication and heat rejection effectiveness. The case drain line must terminate below the minimum oil level in the reservoir to maintain positive return flow under all operating conditions. For models equipped with a brake, the brake leakage oil circuit should drain independently and must not share the motor case drain line.
4. Periodic Parking Brake Inspection and Maintenance
The MK04-2-114-K04-3340-3000 is equipped with an integrated parking brake with minimum release pressure of 17 bar (246 PSI). Periodically inspect brake friction disc wear and brake piston seal condition. Brake release pressure must be set to the value specified in the Poclain technical manual — excessive release pressure will damage seals, while insufficient pressure will cause brake drag and overheating. Replace friction discs when brake clearance exceeds specified limits.
5. Installation Alignment and Tightening Torque
The MK04 uses wheel flange mounting. During installation, verify that the output shaft spline is properly aligned with the mating component. Mounting screws are 5 x M16 x 2, grade 12.9, with tightening torque of 355 Nm (262 lb.ft). Installation misalignment will cause abnormal spline wear and bearing side loading, significantly shortening service life. For wheel drive applications, pay particular attention to the concentricity between the wheel hub and motor flange. The chassis mounting surface Ra roughness should be controlled within 12.5 μm, with flatness tolerance of 0.2 mm.
6. Low-Speed Smoothness Monitoring and Maintenance
One of the MK04 Series’ core advantages is smooth low-speed operation. If crawling or vibration is observed at extremely low speeds, it may indicate increased piston-to-bore clearance, cam ring wear, or flow distribution surface sealing degradation. Record the minimum smooth operating speed under standard conditions quarterly as a trend monitoring baseline; deviation exceeding 15% from the initial value warrants inspection.
