Danfoss 51V Series Variable Hydraulic Motor | 51V80 51V110 51V160 51V250 | High Pressure Bent-Axis

The 51V Series variable displacement bent-axis motors by Chengyuan Hydraulic are high-end power units fully compatible with Danfoss industrial standards. Covering displacements from 51V80 to 51V250, the 51V series is engineered for heavy-duty tasks in both open and closed-loop systems. Its unique bent-axis architecture allows for a wide displacement ratio, delivering exceptional starting torque and ultra-high maximum speeds. As a signature product of Chengyuan, every 51V motor undergoes 100% simulated condition testing, replicating extreme drilling loads and frequent reversals to ensure 100% original-place interchangeability with OEM components.

Technical Specifications :

• Full Model Code: 51V160RC8N D8M1 RJN1 ADA 060AAG3 C232

• Max Displacement: $160\text{ cm}^3/\text{rev}$

• Min Displacement: Adjustable to $0\text{ cm}^3/\text{rev}$ (Based on control settings)

• Nominal Pressure: $40\text{ MPa (400 bar / 5800 psi)}$

• Peak Pressure: $48\text{ MPa (480 bar / 6960 psi)}$

• Max Speed (at full displacement): $3500\text{–}4000\text{ rpm}$

• Max Speed (at min displacement): Exceeding $5000\text{ rpm}$

• Control Type: Proportional hydraulic or pressure-sensing (customized per D8M1 code)

• Sealing: High-pressure resistant Viton (FKM) system

Key Technical Advantages:

• Bent-Axis High-Efficiency Design: Compared to traditional swashplate motors, the 51V series utilizes a bent-axis angle up to 40°. This structure significantly enhances mechanical efficiency and starting torque while providing superior stability at low speeds—essential for precise drilling rotation.

• High Pressure Tolerance & Durable Bearings: Designed for the frequent pressure spikes typical in drilling operations, the internal assembly features reinforced tapered roller bearings and heat-treated valve plates. Volumetric efficiency remains peaked even at 480 bar.

• Flexible Displacement Control Logic: The D8M1 code represents a sophisticated integrated control. The motor adjusts displacement steplessly based on load demand, providing maximum torque at high loads and switching to small displacement for high speed at light loads.

• Exceptional Power Density: The compact bent-axis design allows the 51V160 to output massive power within a limited footprint, which is critical for the power bay layouts of compact rigs like rotary or DTH drills.

Application Areas:

• Drilling Rigs: Power heads for rotary rigs, hoisting mechanisms for water well drills, and coal mine roof bolters.

• Heavy Machinery Travel: Crawler drive motors and travel systems for large construction equipment.

• Industrial Drives: High-pressure winches and heavy-duty agitator drives.

Expert Maintenance Tips:

• Case Drain Configuration: The case drain port must be positioned upward and piped directly to the tank. Maintain the case backpressure below $0.15\text{ MPa (1.5 bar)}$ to prevent shaft seal failure.

• Oil Viscosity Management: To protect the bent-axis components, maintain oil viscosity within the optimal range of $16\text{–}36\text{ mm}^2/\text{s}$. Low viscosity caused by overheating will impair low-speed stability.

• Pre-Filling Before Startup: Due to the unique bent-axis structure, the motor case must be filled with clean hydraulic oil before initial startup. Running the motor dry will cause instantaneous damage to the pistons and rotor assembly.