Product Overview
The Parker Torqmotor™ TG Series hydraulic motor is a low-speed, high-torque (LSHT) gerotor motor engineered for medium-duty applications. Built with a cast iron housing and high-strength alloy bearings, it delivers reliable performance under high-pressure and high-torque conditions. The series spans displacements from 140 to 960 cm³/rev, with intermittent pressures reaching 280 bar and maximum output torque up to 1,490 Nm.
The four models covered herein — TG0195MS051AAAA, TG0405US080BBDL, TG0530MS030AAAB, and TG0625EN440AAAB — are manufactured to Parker OEM specifications with 100% drop-in interchangeability. Every unit undergoes 100% simulated duty-cycle testing before shipment to ensure that installed performance matches genuine Parker products. No modifications to piping, flanges, or drivetrain interfaces are required. The integrated high-pressure shaft seal eliminates the need for a case drain line, simplifying system layout and reducing potential leak paths.
Technical Specifications
TG0195MS051AAAA:
Model: TG0195MS051AAAA
Brand: Parker Torqmotor™ TG Series
Displacement: 195 cm³/r (11.9 in³/r)
Max. Continuous Flow: 20 GPM (25 GPM intermittent)
Max. Continuous Speed: 477 RPM
Max. Continuous Torque: 4,919 in-lbs (6,663 in-lbs intermittent)
Shaft: 1.25″ 14-tooth splined
Mount: SAE “A” 4-hole magneto mount
Port Configuration: #10 ORB ports
Rotation: Reverse timed manifold rotation
Seals: Standard
Fluid Type: Mineral oil (standard)
TG0405US080BBDL:
Model: TG0405US080BBDL
Brand: Parker Torqmotor™ TG Series
Displacement: 405 cm³/r (24.7 in³/r)
Max. Continuous Flow: 20 GPM (25 GPM intermittent)
Max. Continuous Speed: 232 RPM
Max. Continuous Torque: 8,336 in-lbs (11,877 in-lbs intermittent)
Shaft: 1.25″ tapered shaft
Mount: Standard wheel mount
Port Configuration: #10 ORB ports
Special Feature: 2,500 PSI internal bi-directional relief valve
Fluid Type: Mineral oil (standard)
TG0530MS030AAAB:
Model: TG0530MS030AAAB
Brand: Parker Torqmotor™ TG Series
Displacement: 530 cm³/rev (32.94 in³/rev)
Max. Speed: 140 RPM
Max. Torque: 8,673 in-lbs
Max. Flow Rate: 19.81 GPM
Shaft: 1-1/4″ shaft with Woodruff key
Mount: 6-bolt magneto flange mount
Port Configuration: 7/8″-14 SAE
TG0625EN440AAAB:
Model: TG0625EN440AAAB
Brand: Parker Torqmotor™ TG Series
Geometric Displacement: 625 cm³/rev (38.0 in³/rev)
Max. Differential Pressure: 121 bar (1750 PSID) continuous / 155 bar (2250 PSID) intermittent
Max. Supply Pressure: 300 bar (4350 PSIG)
Max. Torque: 986 Nm (8,727 lb-in) continuous / 1,291 Nm (11,424 lb-in) intermittent
Min. Starting Torque: 895 Nm (7,924 lb-in) continuous / 1,165 Nm (10,312 lb-in) intermittent
Max. Power: 20 kW (27 HP)
Max. Speed: 100/120 RPM
Shaft: 1-1/4″ splined shaft (14-tooth)
Mount: 6-bolt heavy-duty flange
Rotation: Counter-clockwise
Fluid Type: Mineral oil (standard)
Key Technical Advantages
1. Patented 60:40 Spline Geometry Power Transmission System
At the heart of the TG Series powertrain is a patented 60:40 spline tooth-width ratio (male-to-female spline width), capable of transmitting torques exceeding 1,470 Nm. From an engineering standpoint, conventional symmetric splines are susceptible to fretting wear under alternating loads. The asymmetric 60:40 tooth profile distributes contact stress more uniformly across the tooth flank, significantly extending the fatigue life of the drivetrain.
2. Continuous Oil Flow Spline Lubrication
The TG Series incorporates internal continuous oil flow channels that constantly flush and lubricate the internal spline pairs during operation. This mechanism keeps the spline pair operating at low temperatures, preventing material degradation and clearance growth caused by localized overheating — a key factor behind the TG Series’ extended service life.
3. High-Pressure Shaft Seal with Case-Drain-Free Design
The TG Series comes standard with a high-pressure shaft seal that allows the motor to operate reliably under elevated back-pressure conditions. The innovative design eliminates the need for an external case drain line, reducing plumbing complexity and potential leak points. For drop-in replacement scenarios, this means no additional drain ports need to be added to the host machine.
4. Superior Side Load Capacity
The TG Series motor withstands dynamic side loads of up to 16,013 N at the key position. This capability, enabled by high-strength alloy bearings paired with a reinforced output shaft, allows the motor to directly drive sprockets, gears, or other radial-load-bearing mechanisms without additional bearing support — simplifying drivetrain design.
5. Cast Iron Housing and Precision Machining
The housing is constructed from high-strength cast iron, with critical internal mating surfaces precision-honed to micron-level tolerances. Cast iron offers a low coefficient of thermal expansion and excellent vibration damping, maintaining stable volumetric efficiency across a wide temperature range. The Gerotor rotor set achieves volumetric efficiencies exceeding 92% under rated conditions.
Application Areas
Construction Machinery: Skid steer wheel drives, excavator attachment drives, compact tool carrier propulsion systems
Agricultural Machinery: Combine header drives, auger drives, specialty harvester wheel drives
Turf & Grounds Care: Zero-turn mower wheel drives, golf course maintenance equipment
Material Handling: Conveyor drives, winch drives, sweeper wheel motors
Forestry Equipment: Wood chipper drives, forestry processor feed systems
Municipal Equipment: Snow removal equipment, salt/sand spreaders, portable irrigation systems
Expert Maintenance Tips
Installation Notes:
Before installation, verify that the flange bolt pattern matches the host machine. The TG Series is available in SAE standard flange and wheel mount configurations. When replacing, confirm the mounting code prefix (e.g., MS, US, EN) to ensure correct interface type.
The TG0405US080BBDL features an integrated 2,500 PSI bi-directional relief valve. Confirm that system operating pressure does not exceed the relief setting to avoid continuous relieving and elevated oil temperatures.
Apply a light coating of grease to the spline shaft before assembly to prevent corrosion and ensure smooth engagement with the coupling or hub.
Operation & Maintenance:
Replace the hydraulic oil filter after the first 50 hours of operation and verify fluid cleanliness (NAS Level 9 or better recommended).
Although the TG Series is designed without a case drain, ensure that return-line back pressure does not exceed the shaft seal’s allowable limit to prevent premature seal failure.
Periodically check flange bolt torque. Re-torque every 500 hours to prevent loosening caused by vibration.
After extended storage, run the motor at low speed and no load for 10–15 minutes before applying full load, allowing the internal oil film to re-establish.
