Danfoss H1B250 – Detailed Technical Specifications

1. Basic Technical Data

The Danfoss H1B250 is a variable displacement bent-axis axial piston motor designed for closed-loop hydrostatic transmissions in heavy-duty mobile machinery.

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2. Displacement & Control Range

• Maximum displacement: 250 cm³/rev
• Minimum displacement (varies by control type):
  • ~120 cm³/rev (standard HE / TA configurations)
  • ~155 cm³/rev (some LH / TH configurations)
  • ~168 cm³/rev (proportional control versions)
• Displacement control type:
  • Hydraulic 2-position control (HE / TH)
  • Hydraulic proportional control (LH / DH / MH)
  • Electric proportional control (12V / 24V)
  • Pressure compensator override versions available
• Control response:
  • Fast swash plate adjustment
  • Stepless displacement change (proportional versions)
  • Optimized for traction and speed control systems

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3. Pressure Ratings

Engineering characteristics:

• High-pressure bent-axis structure
• Reinforced cylinder block and bearing system
• Designed for shock load resistance in mobile equipment

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4. Speed Performance

Key behavior:

• High speed at minimum displacement angle
• High torque at maximum displacement
• Excellent low-speed creep control

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5. Torque Characteristics

The H1B250 delivers very high torque density due to its large displacement.

• High starting torque capability
• Smooth torque output at low speed
• Stable torque under load variation
• Suitable for wheel drive and track drive systems

Typical application output:

• Heavy-duty traction systems (dumpers, loaders)
• High-load start/stop cycles

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6. Hydraulic Efficiency

• Volumetric efficiency: typically > 95% (under rated conditions)
• Mechanical efficiency: optimized due to bent-axis design
• Overall efficiency: high across wide speed range

Efficiency advantages:

• Low internal leakage design
• Reduced friction losses
• Optimized valve plate geometry
• Minimal energy loss in partial displacement mode

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7. Control System Options (Detailed)

7.1 Hydraulic Controls

• HE: 2-position hydraulic control (fail-safe full displacement)
• TH: pressure-controlled minimum displacement logic
• LH: proportional hydraulic control (spring-centered)

7.2 Electric Controls

• 12V proportional solenoid control
• 24V CAN-compatible control versions (depending on configuration)
• Integrated feedback sensor options available

7.3 Advanced Functions

• Pressure compensator override (PCOR)
• Brake pressure defeat function (optional)
• Loop flushing integration
• Speed sensor feedback (inductive or Hall-type)

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8. Mechanical Design Data

Structural advantages:

• High rigidity housing
• Strong bearing support for radial loads
• Long service life under vibration load

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9. Thermal & Operating Limits

Thermal behavior:

• Efficient heat dissipation design
• Suitable for continuous-duty operation
• Stable performance under high ambient temperature

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10. Oil Flow & Auxiliary Functions

• Integrated loop flushing system (optional)
• Flushing flow: typically 30 L/min
• Shuttle pressure: 6.5–12.5 bar (variant dependent)
• Built-in relief valve options
• Charge flow compatibility with H1 pump systems

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11. Durability & Design Life

• Heavy-duty bearing system for high radial loads
• Reinforced piston shoe design
• Long-life cylinder block coating
• Designed for continuous industrial / off-highway duty cycles

Expected service life:

• 10,000 operating hours (depending on system cleanliness & load)