Product Overview
The BMER Series is a medium-duty low-speed, high-torque (LSHT) orbital hydraulic motor featuring a high-speed porting structure and an inlaid-column rotary stator (Geroler gear set) design. Across a displacement range of 125–750 cc/rev, it delivers continuous torque from 325 to 1,085 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 500/530 series motors.
In terms of interchangeability, the BMER Series is standardized to international mounting interfaces — SAE magneto flanges, wheel-mount flanges, keyed shafts, splined shafts (SAE 6B), and 7/8″-14 SAE ports — with dimensional profiles that correspond directly to Parker TG and Eaton 6K series motors. The product range covers the displacement specifications associated with model codes 106, 109, 110, 111, 112, 113, 119, 104, 114, as well as the interchange requirement for Eaton Char-Lynn T Series part number 158-3261-001. Every unit undergoes 100% simulated duty-cycle testing prior to shipment, verifying volumetric efficiency, torque output, and seal integrity before installation.
Technical Specifications
BMER Series Core Specifications (by displacement model):
Series: BMER 125 / 160 / 200 / 230 / 250 / 300 / 350 / 375 / 400 / 475 / 540 / 650 / 750
Geometric Displacement (cm³/rev): 118 / 156 / 196 / 228 / 257 / 296 / 345 / 371 / 405 / 462 / 540 / 647 / 745
Max. Speed Continuous / Intermittent (rpm): 360/490, 375/470, 330/425, 290/365, 290/350, 250/315, 220/270, 200/240, 185/220, 160/195, 140/170, 115/138, 100/120
Max. Torque Continuous / Intermittent / Peak (Nm): 325/380/450, 450/525/590, 530/600/750, 625/710/870, 700/790/980, 810/930/1120, 905/1035/1285, 990/1140/1360, 1010/1180/1360, 1085/1180/1260, 980/1240/1380, 1015/1250/1380, 1050/1180/1370
Max. Output Power Continuous / Intermittent (kW): 12.0/14.0, 15.0/17.5, 15.5/18.0, 16.0/19.0, 17.5/20.0, 18.0/21.0, 17.5/20.0, 16.5/19.0, 15.5/18.0, 14.5/16.5, 11.5/15.0, 10.0/12.0, 8.0/10.0
Max. Pressure Drop Continuous / Intermittent / Peak (MPa): 20.5/24/27.6 (BMER 125–350); 20.5/24/27.6 (BMER 375); 19/22.5/25 (BMER 400); 17.5/19/20.5 (BMER 475, 540); 14/17.5/20.5 (BMER 650); 10.5/12/14 (BMER 750)
Max. Flow Continuous / Intermittent (L/min): 45/60, 60/75, 70/85, 70/85, 75/90, 80/95, 80/95, 75/90, 75/90, 75/90, 75/90, 75/90, 75/90
Weight (kg, BMER 125–750): 12 / 12.1 / 12.3 / 12.4 / 12.6 / 13 / 13.2 / 13.5 / 13.7 / 14 / 14.6 / 15.5 / 16
Mounting Flange: SAE 4-bolt magneto mount (MS) / Wheel mount (WS) / 6-bolt heavy-duty flange
Shaft Options: 25.4 mm splined (SAE 6B) / 31.75 mm splined / 1.25″ keyed / tapered
Port Configuration: 7/8″-14 SAE O-ring / #10 ORB (5/8″)
Rotation: CCW / CW / Bi-directional reversible
Fluid Type: Mineral oil (standard), recommended viscosity 32–68 mm²/s
System Filtration: 10 μm nominal, magnet installed in filter or tank bottom recommended
Key Technical Advantages
1. Pressure-Compensated Balance Plate — The Engineering Basis for Low-Speed, High-Volumetric Efficiency
The BMER Series employs a pressure balance plate that flexes toward the rotor during startup, minimizing internal leakage and boosting volumetric efficiency. As the motor reaches operating pressure, the plate relaxes, allowing the rotor to turn freely and reducing mechanical friction losses. This dynamic “seal-on-start, release-on-run” mechanism enables the BMER Series to maintain a stable balance between volumetric and mechanical efficiency under low-flow, high-pressure conditions.
2. Inlaid-Column Geroler Gear Set with High-Speed Porting
The core gear set features an inlaid-column rotary stator paired with a 6:1 speed-ratio valve plate-to-output-shaft relationship, achieving porting accuracy of ±0.25%. The high-pressure porting structure automatically compensates for clearance changes during operation, delivering volumetric efficiency exceeding 95% and a minimum stable speed of 2 RPM — a significant advantage in AGV drive, hydraulic winch, and other low-speed precision control applications.
3. Heavy-Duty Drive Link with Full-Flow Lubrication
The heavy-duty drive link in the power transmission path receives full-flow lubrication during operation, effectively reducing contact fatigue and fretting wear on the spline pair. The output shaft is fitted with tapered roller bearings that accommodate high axial and radial loads simultaneously, allowing the motor to directly drive sprockets, gears, and other radial-load mechanisms without additional bearing support structures.
4. High-Pressure Shaft Seal with Case-Drain-Free Design
The BMER Series comes standard with a high-pressure shaft seal that maintains reliable sealing under back-pressure conditions and eliminates the need for an external case drain line. For replacement applications, this means no additional drain ports are required on the host machine, reducing plumbing complexity and potential leak paths.
5. Standardized Interchange Design and ISO Quality Management
The BMER Series is manufactured under the ISO 9001-2000 quality system. Mounting interfaces — flange bolt patterns, shaft dimensions, and port specifications — correspond directly to Parker TG/TF, Eaton 6K, Danfoss OMS, and White 500/530 series motors, enabling true drop-in interchangeability. The part numbers of interest — 158-3261-001 (Eaton Char-Lynn T Series) and model codes 104, 106, 109–114, 119 — all have corresponding displacement and interface specifications within the BMER Series.
Application Areas
Construction Machinery: Skid steer wheel drives, mini excavator travel motors, road paver drive systems
Agricultural Machinery: Combine header drives, auger drives, irrigation equipment
Turf & Grounds Care: Zero-turn mower wheel drives, golf course maintenance equipment
Material Handling: Conveyor drives, hydraulic winches, forklift attachment drives
Municipal Equipment: Snow removal vehicles, sweepers, aerial work platform travel drives
Specialty Vehicles: AGV drive units, hydraulic powerpack integration
Expert Maintenance Tips
Installation Notes:
Before installation, verify that the flange bolt pattern matches the host machine. The BMER Series offers three interface options: 4-bolt magneto mount (MS), wheel mount (WS), and 6-bolt heavy-duty flange. Confirm the original flange code when replacing.
Apply a light coating of grease to the spline shaft before assembly to prevent corrosion and ensure smooth engagement. For keyed shafts, verify key dimensions and keyway tolerances.
System filtration should be maintained at 10 μm nominal or better, with a magnet installed in the filter or at the tank bottom to capture ferromagnetic particles.
Operation & Maintenance:
Replace the hydraulic oil filter after the first 50 hours of operation and verify fluid cleanliness. Recommended oil viscosity range is 32–68 mm²/s; normal operating oil temperature should be maintained 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.
When case pressure exceeds 20 bar, an external drain line to the tank is recommended to protect the shaft seal and extend service life.
Periodically check flange bolt torque. Re-torque every 500 hours to prevent loosening caused by vibration.
