Product Overview
The TMT400 is a heavy-duty disc-valve orbital hydraulic motor in the Danfoss TMT series, engineered for high-torque, low-speed applications in demanding mobile hydraulic systems. Featuring a roller gear set that reduces internal friction and improves mechanical efficiency at start-up and low speeds, combined with a robust cardan shaft-driven disc valve, the TMT400 delivers reliable performance under heavy radial and axial loads.
Designed as a 100% drop-in replacement for Danfoss TMT400 series motors (including part numbers 151Z3028, 151Z3265, 11025856, and 11045433), the TMT400 matches mounting flanges, shaft specifications, and port configurations exactly — no system modification required. Suitable for both open and closed hydraulic circuits, every unit undergoes 100% simulated load testing before shipment, validated across rated pressure, rated speed, and peak torque conditions.
Technical Specifications
Model: TMT400
Displacement: 401.6 cm³/rev (geometric displacement 410.9 cm³/rev)
Rated Pressure (Continuous): 210 bar (21 MPa)
Peak Pressure (Intermittent): 250 bar (25 MPa)
Max Continuous Speed: 375 rpm
Max Continuous Torque: 1,150 N·m
Control Type: Face distribution (disc valve), short cardan shaft-driven valve
Bearing Type: Tapered roller bearings (high radial & axial load capacity)
Mounting Flange: Square flange, pilot Ø125 mm, bolt circle Ø160 mm
Shaft Type: Ø50 mm cylindrical with key A12×8×75 (splined 17T version available)
Port Size: G 1 BSPP main port / G 1/4 drain port
Rotation: Bi-directional
Recommended Viscosity: 37–73 cSt
Oil Cleanliness: ISO 18/13
Weight: Approx. 25.5 kg
Key Technical Advantages
1. Low-Friction Roller Gear Set
The TMT400 utilizes a roller gear set instead of conventional gear meshing, significantly reducing internal friction at start-up and low speeds. This enables smooth torque output without stick-slip effects from 5 to 50 rpm while improving mechanical efficiency and reducing energy losses.
2. High-Strength Cardan Shaft Drive System
The disc valve is driven by a short cardan shaft designed to withstand high radial and axial loads, ensuring long service life under heavy-duty conditions. The cardan shaft arrangement effectively isolates output shaft loads from the distribution face, enhancing distribution system reliability.
3. High Back-Pressure Shaft Seal
The high-pressure shaft seal allows elevated return-line back pressure without requiring an external drain line. In series-connected motor circuits or systems with high return-line resistance, the TMT400 simplifies circuit design and reduces plumbing costs.
4. Bi-Directional Equal Torque Output
The TMT400 produces symmetrical torque output in both rotational directions. The symmetrical design of the face distribution structure ensures consistent volumetric and mechanical efficiency in both directions, making it ideal for travel-drive and other bi-directional load applications.
5. 100% Simulated Load Testing
Every TMT400 is validated on a 100% simulated load test bench before shipment. Testing protocols cover continuous operation at rated pressure, cyclic intermittent pressure loading, peak torque output, and internal leakage measurement, ensuring delivered performance matches published specifications.
Application Areas
Construction Machinery: Loader travel drive, excavator swing drive, vibratory roller drum drive
Agricultural Machinery: Combine harvester drive systems, tractor hydraulic hitch, rotary tiller blade shaft drive
Forestry Equipment: Feller buncher feed roller drive, skidder winch drive
Material Handling: Forklift travel drive, conveyor drive, winch/haulage drive
Municipal Vehicles: Road sweeper, refuse compactor, snow removal equipment
Expert Maintenance Tips
Pre-Installation Checklist: Verify system oil cleanliness meets ISO 18/13. Use a return filter rated at 10 μm or finer. Ensure the Ø125 mm pilot flange fits flush against the mounting surface. Tighten bolts in a diagonal sequence. Confirm proper key fit between shaft and coupling to avoid eccentric loading.
Case Drain Configuration: When system back pressure exceeds the shaft seal rating, connect the external drain line to the G 1/4 drain port. The drain line should remain unobstructed with the outlet submerged below reservoir oil level to prevent air ingestion. Install a restrictor to maintain at least 3.5 bar case pressure.
Break-In Procedure: Before full-load operation, run new or overhauled motors at no more than 30% of continuous ratings for at least 30 minutes. This allows the roller gear set, distribution face, and bearings to achieve optimal mating surfaces.
Fluid Management: Use 68# anti-wear hydraulic oil with working viscosity maintained at 37–73 cSt. Normal operating oil temperature should be 20–60°C. Monitor oil cleanliness regularly; replace hydraulic fluid and clean filters immediately when contamination exceeds ISO 19/16.
Long-Term Storage: For storage exceeding 3 months, fill the motor interior with clean hydraulic oil and plug all ports to prevent internal corrosion. Before recommissioning, manually rotate the shaft to confirm free movement without binding.
