Description
🔧 Mitsubishi HG903-D48 / HG903S-D48 – Description
The HG903-D48 (HG903S-D48) is a high-power Mitsubishi Electric HG Series AC servo / spindle-class motor, and it is one of the largest standard HG frame motors in your list.
It is designed for very high torque industrial CNC applications, commonly used as a main spindle motor or heavy-duty rotary axis motor in large machining centers.
⚙️ Key Description
- Series: Mitsubishi HG (MELSERVO / CNC spindle & heavy-axis family)
- Type: AC brushless rotary motor (servo / spindle duty)
- Encoder: 20-bit absolute encoder (D48 type, ~1,048,576 pulses/rev)
- Application: CNC spindle drives, heavy feed axes, large machining centers
- Voltage class: 200 VAC industrial CNC drive system
📊 Electrical & Performance Specs
From Mitsubishi HG-series official data:
- Rated output: 9.0 kW
- Rated torque: 28.6 N·m
- Rated speed: 3000 rpm
- Maximum speed: up to 3000–6000 rpm (system dependent)
- Maximum torque: ~208 N·m (peak)
- Maximum current: ~204 A class
- Motor inertia: ~196 ×10⁻⁴ kg·m²
🧩 Mechanical Features
- Frame size: ~204 mm class flange (very large frame motor)
- Protection: IP67 (shaft excluded)
- Construction: Heavy-duty enclosed industrial servo/spindle motor
- Design: Medium inertia, high torque output
- Mounting: CNC spindle / large axis drive mounting
⚙️ Functional Characteristics
The HG903-D48 is not a small feed-axis servo like HG54–HG154.
It is designed for:
- Main spindle drive in CNC machines (primary use)
- OR very heavy industrial axis drive systems
- High continuous torque at low RPM
- Stable cutting performance under heavy load
🏭 Typical Applications
- CNC machine main spindle systems
- Large vertical / horizontal machining centers
- Heavy-duty milling and boring machines
- High-torque rotary tables
- Industrial machine tools requiring strong continuous cutting power
⚠️ Important Note
- ❌ Not a small feed-axis servo (like HG54, HG105, HG154)
- ❌ Not a linear motor (LM series = direct-drive linear axis)
- ⚠️ This is effectively the top-end HG spindle/torque class motor
- ✅ Designed for main cutting spindle or very heavy drive applications
⚡ Summary
The HG903-D48 is:
- A 9.0 kW industrial CNC spindle/servo motor
- One of the highest-power HG standard motors
- Very high torque (~28.6 N·m rated, >200 N·m peak)
- Used for main spindle and heavy-duty machining applications