BMER-2-300-WD BMER Series Hydraulic Motor Parker TG Eaton 6K

Product Overview

The BMER Series is a medium-to-heavy-duty low-speed, high-torque (LSHT) orbital hydraulic motor featuring an inlaid-column rotary stator (Geroler) design with high-speed porting. It spans displacements from 118 to 745 cm³/rev, achieves a maximum continuous pressure drop of 20.5 MPa, and delivers peak torque up to 1,380 Nm. The series is engineered as a high-quality drop-in interchange replacement for Parker TG/TF, Eaton Char-Lynn 6K, Danfoss OMS, and White 500/501 series motors.

The focus model BMER-2-300-WD features a wheel-mount configuration with a 4-bolt wheel flange (WD code), pilot diameter 82.55 mm × 5 mm, 31.75 mm tapered output shaft with 7.96 × 7.96 × 25.4 mm parallel key, and G 1/2″ ports. This configuration directly replaces the White 400300W3820AAAAA TE Series motor with fully matching mounting dimensions and interfaces. The series covers 13 displacement classes — BMER-125, 160, 200, 230, 250, 300, 350, 375, 400, 475, 540, 650, and 750. Every unit undergoes 100% simulated duty-cycle testing before shipment, verifying volumetric efficiency, torque output, and seal integrity.

Technical Specifications 

BMER-2-300-WD Core Specifications:

• Model: BMER-2-300-WD

• Series: BMER-2 Series (BMER-125 / 160 / 200 / 230 / 250 / 300 / 350 / 375 / 400 / 475 / 540 / 650 / 750)

• Geometric Displacement: 296 cm³/rev (300 ml/r)

• Max. Speed Continuous / Intermittent: 250 / 315 rpm

• Max. Torque Continuous / Intermittent / Peak: 810 / 930 / 1,120 Nm

• Max. Output Power Continuous / Intermittent: 18.0 / 21.0 kW

• Max. Pressure Drop Continuous / Intermittent / Peak: 20.5 / 24 / 27.6 MPa

• Max. Flow Continuous / Intermittent: 80 / 95 L/min

• Mounting Flange: Wheel mount (WD code), 4-bolt, pilot 82.55 mm × 5 mm

• Output Shaft: 31.75 mm tapered, parallel key 7.96 × 7.96 × 25.4 mm

• Ports: G 1/2″

• Bearings: Tapered roller bearings, front and rear

• Rotation: CCW / CW options

• Weight: Approx. 13 kg

• Fluid Type: Mineral oil, recommended viscosity 32–68 mm²/s

BMER Series Full Displacement Range (by Model):

• BMER 125: 118 cm³/rev, 360 rpm continuous, 325 Nm continuous torque

• BMER 160: 156 cm³/rev, 375 rpm continuous, 450 Nm continuous torque

• BMER 200: 196 cm³/rev, 330 rpm continuous, 530 Nm continuous torque

• BMER 230: 228 cm³/rev, 290 rpm continuous, 625 Nm continuous torque

• BMER 250: 257 cm³/rev, 290 rpm continuous, 700 Nm continuous torque

• BMER 300: 296 cm³/rev, 250 rpm continuous, 810 Nm continuous torque

• BMER 350: 345 cm³/rev, 220 rpm continuous, 905 Nm continuous torque

• BMER 375: 371 cm³/rev, 200 rpm continuous, 990 Nm continuous torque

• BMER 400: 405 cm³/rev, 185 rpm continuous, 1,010 Nm continuous torque

• BMER 475: 462 cm³/rev, 160 rpm continuous, 1,085 Nm continuous torque

• BMER 540: 540 cm³/rev, 140 rpm continuous, 980 Nm continuous torque

• BMER 650: 647 cm³/rev, 115 rpm continuous, 1,015 Nm continuous torque

• BMER 750: 745 cm³/rev, 100 rpm continuous, 1,050 Nm continuous torque

Key Technical Advantages

1. Inlaid-Column Geroler Stator with High-Speed Porting
The BMER Series employs an inlaid-column rotary stator paired with a high-speed porting valve plate, achieving superior porting accuracy. The key engineering advantage of the inlaid-column stator lies in its rolling contact: the columns roll within the stator curve rather than sliding, dramatically reducing friction coefficients. This enables a starting pressure as low as 1.5 MPa and a minimum stable speed of 2 rpm. Volumetric efficiency exceeds 95%, and dual-stage wear compensation maintains volumetric efficiency above 98% throughout the service life.

2. Tapered Roller Bearings for Direct Wheel Drive
The BMER-2-300-WD output shaft is fitted with tapered roller bearings at front and rear positions, simultaneously accommodating high radial and axial loads. This allows the motor to directly drive wheels or sprockets without additional bearing support structures. The conical raceway geometry decomposes combined loads into components along the roller axis, distributing contact stress more uniformly and ensuring smooth operation under both low-speed startup and high-pressure running conditions.

3. Pressure-Compensated Balance Plate for Low-Leakage Operation
The BMER Series employs a pressure balance plate that flexes toward the rotor during startup, significantly reducing internal leakage. At operating pressure, the plate relaxes, allowing the rotor to turn freely and reducing mechanical friction losses. This dynamic mechanism enables the BMER Series to maintain an optimal balance between volumetric and mechanical efficiency under low-flow, high-pressure conditions — ideal for travel drive applications requiring precise low-speed control.

4. Cast Iron Housing with Heavy-Duty Structural Design
The BMER Series utilizes a high-strength cast iron housing with precision-machined critical mating surfaces. The engineering advantages of cast iron in hydraulic motors include a low coefficient of thermal expansion and excellent vibration damping, maintaining stable clearances and volumetric efficiency across a wide temperature range. Combined with the inlaid-column Geroler set’s high efficiency retention design, the motor sustains high operating efficiency even after extended service.

5. Broad Brand Interchange Compatibility
The BMER Series corresponds directly to Parker TG/TF, Eaton Char-Lynn 6K, Danfoss OMS, and White 500/501 series motors in terms of flange mounting dimensions, shaft specifications, and port configurations, enabling true drop-in interchangeability. The BMER-2-300-WD directly replaces the White 400300W3820AAAAA TE Series motor, with the WD flange code corresponding to a 4-bolt wheel mount, pilot 82.55 mm × 5 mm, G 1/2″ ports, and 31.75 mm tapered shaft.

Application Areas

• Construction Equipment: Skid steer wheel drives, road paver travel systems, mini excavators

• Aerial Work Platforms: Scissor lift travel drives, articulated boom lift drives

• Agricultural Equipment: Combine harvesters, tractor attachment drives, irrigation equipment

• Municipal Equipment: Street sweepers, snow removal equipment, refuse compactors

• Material Handling: Forklift travel drives, conveyor drives, hydraulic winches

• Specialty Vehicles: AGV drive units, hydraulic powerpack integration

Expert Maintenance Tips

Installation Notes:

• The BMER-2-300-WD uses a 4-bolt wheel mount flange with pilot diameter 82.55 mm × 5 mm. Verify the host machine’s flange pilot and bolt pattern match before installation, and ensure the pilot face is clean and free of debris.

• The output shaft is a 31.75 mm tapered shaft with 7.96 × 7.96 × 25.4 mm parallel key. Apply a light coating of grease to the tapered surface and keyway before assembly to prevent corrosion and ensure smooth engagement.

• Ports are G 1/2″. Use appropriate sealing washers during installation and avoid over-torquing to prevent thread damage.

Operation & Maintenance:

• Replace the hydraulic oil filter after the first 50 hours of operation and verify fluid cleanliness to NAS Level 9 or ISO 18/16/13 or better.

• Recommended oil viscosity range is 32–68 mm²/s; maintain normal operating oil temperature between 20°C and 60°C.

• After installation, run the new motor at 30% of rated pressure or less for at least 1 hour for run-in before gradually loading to rated conditions.

• Periodically check flange bolt torque. Re-torque every 500 hours to prevent loosening caused by vibration.

• When case pressure exceeds shaft seal limits, an independent drain line routed to the reservoir (below oil level) is recommended.