JMDG6-400 Radial Piston Hydraulic Motor 397cc 20MPa

Product Overview

The JMDG6 series (JMDG6-400, JMDG6-450, JMDG6-500, JMDG6-600, JMDG6-700, JMDG6-750), JMDG11 series, JMDG16 series, JMDG31 series, and JMDG100 series are crankshaft connecting rod radial piston hydraulic motors from the JMDG family (also known as “external five-star motors”)—low-speed high-torque (LSHT) radial piston hydraulic motors. The series features a five-piston eccentric shaft structure with five pistons radially arranged at 72° intervals in a five-star configuration.

The JMDG series motors are designed and manufactured according to Italian standards with adaptations for the Chinese market. Key components are machined on imported machining centers and CNC equipment, with castings produced using polyester sand ductile iron precision casting. All seals and high-strength hexagon socket screws are imported from Germany, Italy, and Taiwan.

The JMDG series covers a wide displacement range from JMDG6 (397–799 cc/rev) to JMDG100 (6300–10000 cc/rev). The product portfolio includes JMDG6 series (400–800 cc/rev), JMDG11 series (700–1300 cc/rev), JMDG16 series (1400–2300 cc/rev), JMDG31 series (2500–5000 cc/rev), and JMDG100 series (6300–10000 cc/rev) . Rated pressures range from 14 to 32 MPa, meeting requirements from light-duty to ultra-heavy-duty applications.

Designed as 100% interchangeable direct replacements for original JMDG series motors, these products match OEM specifications in mounting dimensions, porting interfaces, and performance characteristics. Every unit undergoes 100% simulated duty cycle testing prior to shipment, validating volumetric efficiency, mechanical efficiency, and sealing integrity under actual operating load conditions.

The JMDG series is widely applied in hydraulic transmission systems for petroleum, chemical, mining, marine, and construction machinery—particularly suited for injection molding machine screw drives, winches, drums, various rotary mechanism drives, and tracked or wheeled travel drives.

Technical Specifications 

JMDG6 Series

• Series Name: JMDG6 Crankshaft Connecting Rod Radial Piston Motor (External Five-Star Motor)

• Structure: Five-piston eccentric shaft, 72° radial arrangement

• Rotation Direction: Reversible

• Operating Oil Temperature: 20°C–80°C

JMDG6-400

• Displacement: 397 cc/rev

• Rated Pressure: 16 MPa

• Max Pressure: 20 MPa

• Rated Torque: 930 N.m

• Max Torque: 1160 N.m

• Speed Range: 7–800 r/min

• Max Power: 52 kW

• Weight: 66 kg

JMDG6-450

• Displacement: 452 cc/rev

• Rated Pressure: 16 MPa

• Max Pressure: 20 MPa

• Rated Torque: 1059 N.m

• Max Torque: 1320 N.m

• Speed Range: 7–700 r/min

JMDG6-500

• Displacement: 491 cc/rev

• Rated Pressure: 16 MPa

• Max Pressure: 20 MPa

• Rated Torque: 1150 N.m

• Max Torque: 1440 N.m

• Speed Range: 7–600 r/min

JMDG6-600

• Displacement: 594 cc/rev

• Rated Pressure: 16 MPa

• Max Pressure: 20 MPa

• Rated Torque: 1392 N.m

• Max Torque: 1740 N.m

• Speed Range: 7–500 r/min

JMDG6-700

• Displacement: 683 cc/rev

• Rated Pressure: 16 MPa

• Max Pressure: 20 MPa

• Rated Torque: 1600 N.m

• Max Torque: 2000 N.m

• Speed Range: 6–420 r/min

JMDG6-750

• Displacement: 754 cc/rev

• Rated Pressure: 14 MPa

• Max Pressure: 16 MPa

• Rated Torque: 1546 N.m

• Max Torque: 1760 N.m

• Speed Range: 6–350 r/min

• Max Power: 110 kW

JMDG6-800

• Displacement: 799 cc/rev

• Rated Pressure: 14 MPa

• Max Pressure: 16 MPa

• Rated Torque: 1446 N.m

• Max Torque: 1872 N.m

• Speed Range: 6–330 r/min

JMDG11 Series

• Series Name: JMDG11 Crankshaft Connecting Rod Radial Piston Motor (External Five-Star Motor)

• Structure: Five-piston eccentric shaft, 72° radial arrangement

• Rated Pressure: 14–16 MPa

• Max Pressure: 16–20 MPa

• Speed Range: 18–280 r/min

• Rotation Direction: Reversible

JMDG11-700

• Displacement: 714 cc/rev

• Rated Torque: 1673 N.m

• Max Torque: 2080 N.m

• Max Power: 80 kW

• Weight: 90 kg

JMDG11-800

• Displacement: 782 cc/rev

• Rated Torque: 1832 N.m

• Max Torque: 2280 N.m

JMDG11-900

• Displacement: 903 cc/rev

• Rated Torque: 1955 N.m

• Max Torque: 2444 N.m

JMDG11-1000

• Displacement: 990 cc/rev

• Rated Torque: 2332 N.m

• Max Torque: 2920 N.m

JMDG11-1100

• Displacement: 1116 cc/rev

• Rated Torque: 2615 N.m

• Max Torque: 3260 N.m

JMDG11-1200

• Displacement: 1175 cc/rev

• Rated Torque: 2409 N.m

• Max Torque: 2752 N.m

JMDG11-1300

• Displacement: 1296 cc/rev

• Rated Torque: 2658 N.m

• Max Torque: 3040 N.m

JMDG16 Series

• Series Name: JMDG16 Crankshaft Connecting Rod Radial Piston Motor (External Five-Star Motor)

• Structure: Five-piston eccentric shaft, 72° radial arrangement

• Rated Pressure: 25–32 MPa

• Max Pressure: 25–32 MPa

• Speed Range: 2–400 r/min

• Rotation Direction: Reversible

JMDG16-1400

• Displacement: 1375 cc/rev

• Rated Torque: 5138 N.m

• Max Power: 100 kW

• Weight: 160 kg

JMDG16-1600

• Displacement: 1648 cc/rev

• Rated Torque: 6158 N.m

JMDG31 Series

• Series Name: JMDG31 Crankshaft Connecting Rod Radial Piston Motor (External Five-Star Motor)

• Structure: Five-piston eccentric shaft, 72° radial arrangement

• Rated Pressure: 16–25 MPa

• Max Pressure: 20–32 MPa

• Speed Range: 1–200 r/min

• Rotation Direction: Reversible

JMDG31-2500

• Displacement: 2553 cc/rev

• Rated Torque: 9438 N.m

• Max Power: 298 kW

JMDG31-2800

• Displacement: 2826 cc/rev

JMDG31-3000

• Displacement: 3063 cc/rev

• Rated Torque: 9057 N.m

JMDG31-5000

• Displacement: 4828 cc/rev

• Rated Torque: 11423 N.m

JMDG100 Series

• Series Name: JMDG100 Crankshaft Connecting Rod Radial Piston Motor (External Five-Star Motor)

• Structure: Five-piston eccentric shaft, 72° radial arrangement

• Rated Pressure: 20–25 MPa

• Max Pressure: 25–32 MPa

• Rotation Direction: Reversible

JMDG100-6300

• Displacement: 6300 cc/rev

JMDG100-8000

• Displacement: 8000 cc/rev

JMDG100-10000

• Displacement: 10000 cc/rev

Key Technical Advantages

1. Crankshaft Connecting Rod Radial Piston Design for Extreme Torque Output

The JMDG series employs a crankshaft connecting rod radial piston architecture with five radially arranged pistons at 72° intervals. Roller bearings between the crankshaft and connecting rods deliver high mechanical efficiency. The JMDG16-1400 delivers up to 5138 N.m maximum output torque, the JMDG31-2500 delivers 9438 N.m rated torque, and the JMDG100 series reaches displacements up to 10000 cc/rev.

2. Five-Piston Eccentric Shaft Structure for Low-Noise Operation

The eccentric shaft design with lower excitation frequency five-piston configuration delivers exceptionally low noise output. This makes the JMDG series particularly suitable for indoor equipment and work sites with strict noise requirements.

3. Wide Displacement Coverage with Modular Design

The JMDG series covers a wide displacement range from JMDG6 (397 cc/rev) to JMDG100 (10000 cc/rev). JMDG6 covers 400–800 cc/rev, JMDG11 covers 700–1300 cc/rev, JMDG16 covers 1400–2300 cc/rev, JMDG31 covers 2500–5000 cc/rev, and JMDG100 covers 6300–10000 cc/rev. This modular design enables precise selection based on specific application requirements.

4. 100% Interchangeability – Zero-Modification Drop-In Replacement

Manufactured to exact OEM mounting dimensions, porting specifications, and performance standards, these motors achieve 100% interchangeability with original JMDG series units. No machine modifications are required—simply replace and resume operation, minimizing downtime and reducing maintenance costs.

5. 100% Simulated Duty Cycle Testing for Extreme Environment Reliability

Every motor undergoes 100% simulated duty cycle testing before shipment, validating performance under rated and peak pressure conditions—ensuring long-term reliability in demanding mobile and industrial applications.

6. Excellent Low-Speed Stability with Wide Speed Range

JMDG series motors deliver exceptional low-speed stability—operating smoothly at speeds as low as 1–2 r/min. The wide speed range spans from 1–7 r/min minimum to 400–800 r/min maximum.

7. High Starting Torque with Superior Efficiency

Starting mechanical efficiency reaches 0.9 or higher, ensuring reliable torque output during heavy-load start-up. Roller bearing support between the crankshaft and connecting rods further enhances mechanical efficiency.

8. Precision Casting with Imported Machining – Quality Assurance

Castings utilize ductile iron precision casting, with critical components machined on imported machining centers and CNC equipment. All seals and high-strength fasteners are imported from Germany, Italy, and Taiwan. Precision machining of critical friction pairs ensures long-term reliability under high-load and high-impact conditions.

Application Areas

• Injection Molding Machinery: Screw drives (particularly well-suited)

• Construction Equipment: Excavator travel drives, tracked travel mechanisms, rotary mechanism drives

• Building Machinery: Concrete mixers, tower crane rotary drives

• Mining Equipment: Mine hoists, mining transport equipment travel drives

• Marine & Port: Winch drives, drum drives, deck machinery

• Petroleum & Chemical: Oil drilling equipment, chemical machinery hydraulic drives

• Metallurgical Machinery: Metallurgical equipment hydraulic drives

• Hoisting Machinery: Hoists, crane rotary and travel drives

• Coal Mining Machinery: Coal mining equipment hydraulic drives

Expert Maintenance Tips

1. Housing Pressure Limits: JMDG series motor housing working pressure is 0.1 MPa, with maximum pressure of 0.5 MPa. Ensure the case drain line is unobstructed during installation to prevent seal damage from excessive housing pressure.

2. Pre-Installation Preparation: Before using the JMDG series motor, read and understand the complete instruction manual. For first commissioning, fill the motor housing with hydraulic fluid using a filling unit with filtration not less than 10 µm. Never operate the motor without fluid.

3. Working Pressure Selection: JMDG series hydraulic motors have continuous working rated pressures of 16 MPa, 20 MPa, 25 MPa, and 32 MPa. Select the actual working pressure based on the motor’s service life requirements.

4. Oil Temperature Control: Ensure the hydraulic system operating oil temperature remains within the 20°C–80°C range to prevent viscosity reduction and seal degradation from excessive temperatures.

5. Seal Maintenance: Use OEM-specification imported seals to ensure sealing performance and service life.

6. Regular Inspection Schedule: Regular inspection of the hydraulic system and motor is recommended. Check hydraulic fluid level daily and monitor operating temperature, noise levels, and case drain flow regularly. Abnormal increases may indicate internal wear or seal degradation.

7. Rotation Direction: JMDG series motors feature reversible rotation—confirm inlet/outlet port connections based on actual requirements during installation.