Description
SJ-DJ7.5/120-01 is a Mitsubishi Electric SJ-DJ series compact & lightweight CNC spindle motor optimized for high-speed machining and rapid spindle acceleration.
The SJ-DJ family is Mitsubishi’s lightweight spindle motor series designed for compact machining centers and fast spindle response. (mitsubishielectric.com)
🔧 Key specifications (SJ-DJ7.5/120-01)
| Parameter | Value |
|---|---|
| Series | SJ-DJ |
| Type | Compact & lightweight AC spindle motor |
| Continuous rated output | 5.5 kW |
| Short-time rated output | 7.5 kW (25% ED) |
| Standard accel/decel output | 7.5 kW |
| Actual accel/decel output | 9.0 kW |
| Base speed | 1500 rpm |
| Maximum speed | 12,000 rpm |
| Continuous rated torque | 35.0 N·m |
| Frame number | A112 |
| Shaft diameter | Ø32 mm |
| Flange fitting diameter | Ø180 mm |
| Approx. mass | ~50 kg |
| Protection class | IP54 (shaft excluded) |
| Compatible spindle drive | MDS-DJ-SP-160 / MDS-EJ-SP-160 |
These specifications are listed in Mitsubishi’s official MDS-DJ / MDS-EJ spindle specification manuals. (mitsubishielectric-cnc.com)
⚙️ Difference between /100 and /120 versions
| Model | Max Speed | Main Optimization |
|---|---|---|
| SJ-DJ7.5/100-01 | 10,000 rpm | Higher torque emphasis |
| SJ-DJ7.5/120-01 | 12,000 rpm | Higher speed emphasis |
The /120 version is designed for:
- faster spindle speeds
- precision finishing
- rapid acceleration/deceleration
- high-speed machining centers
⚙️ What makes the SJ-DJ series different
Standard SJ-D
- Conventional spindle motor
- Heavier construction
- General machining use
SJ-DJ
- Compact and lightweight
- Lower rotor inertia
- Faster spindle response
- Reduced machine weight
- Better for compact/high-speed CNC machines
Mitsubishi officially classifies SJ-DJ as a “Compact & lightweight spindle motor” series. (mitsubishielectric.com)
🏭 Typical applications
Used in:
- compact machining centers
- high-speed vertical CNC mills
- drilling/tapping centers
- precision milling systems
- production machines needing quick spindle acceleration
⚠️ Important notes
- Not a positioning servo motor
- Not a linear motor
- Requires Mitsubishi spindle drive electronics
- Cooling and bearing condition are critical at 12,000 rpm
- Must use compatible Mitsubishi spindle amplifiers
🧠 Simple explanation
SJ-DJ7.5/120-01 is a compact and lightweight 7.5 kW-class CNC spindle motor optimized for high-speed machining up to 12,000 rpm with fast spindle acceleration and low inertia.