🔧 What is the GM21VA-A-45/76 Rotary Group?

This component is the main hydraulic rotating group inside the Nabtesco GM21VA travel motor, commonly used in crawler excavators.

The rotary group consists of:

• Cylinder block
• Pistons (piston set)
• Retainer plate
• Valve plate

👉 It is the core unit that converts hydraulic pressure into rotational motion.

⚙️ Basic Information

• Type: Hydraulic travel motor
• Application: Mini and medium crawler excavators
• Function: Generates torque to drive the tracks
• Typically used with: Planetary reduction gearbox (final drive system)

🏗️ Application Range

The GM21VA series (Nabtesco GM Series) is specifically recommended for:

• 10–14 ton class crawler excavators

🔩 Technical Specifications

• Maximum Torque: 20,600 N·m (2100 kgf·m)
• Gear Ratio: 1 / R = 60
• Maximum Operating Pressure: 34.8 MPa (355 kgf/cm²)
• Maximum Displacement: 82.8 cm³/rev