AC servo motor
Yaskawa Sigma-7 rotary servomotors (SGM7J / SGM7A / SGM7G)
Yaskawa's established AC servo motor generation with 24-bit encoders, covering low-inertia, medium-inertia and high-torque families from 200 W to 15 kW on 400 V.
Key specifications
| Rated torque (max) | 22.3 Nm |
|---|---|
| Peak torque (max) | 54 Nm |
| Speed (max) | 6,000 rpm |
| Power (max) | 15,000 W |
| Supply | 400 Vac class (200 V class also offered) |
| Feedback | 24-bit absolute or incremental encoder |
Summarised in our own words from Yaskawa Electric Corporation's published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1
Notes on this data
From Sigma-7 400 V catalogue (German edition): SGM7J 0.2-1.5 kW, 0.637-4.77 Nm rated, 14.3 Nm peak; SGM7A 0.2-7 kW, up to 22.3 Nm rated, 54 Nm peak; SGM7G 450 W-15 kW at 1500 rpm but its torque figures were not in the extract, so torque maxima understate SGM7G. 200 V catalogue not read. Status current, though Sigma-X is the newer generation.
Specify Motion is not affiliated with Yaskawa Electric Corporation. Yaskawa and Sigma-7 rotary servomotors (SGM7J / SGM7A / SGM7G) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a Yaskawa part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Kinco's current-generation AC servo motor line, matched to the JD2 and FD5P PRO drives. Small-inertia 40-80 mm frames run at 3000 rpm on 220 V; large-inertia 130 and 180 mm frames are 1500 rpm machines reaching 47.8 Nm rated and 7.5 kW, with 23-bit multi-turn absolute encoders as standard.
| Published maximum | Sigma-7 rotary servomotors (SGM7J / SGM7A / SGM7G) | SMK Series AC Servo Motors (SMK40S/60S… |
|---|---|---|
| Rated torque | 22.3 Nm | 47.8 Nm meets or exceeds |
| Peak torque | 54 Nm | 119.5 Nm meets or exceeds |
| Speed | 6,000 rpm | 6,000 rpm meets or exceeds |
| Power | 15,000 W | 7,500 W |
Kinco's established AC servo motor range from 40 to 180 mm frames, covering 50 W to 7.5 kW and up to 48 Nm rated torque. Standard feedback is a 2500-line incremental encoder with Hall commutation, with absolute options and a resolver on the 180 mm frame. Pairs with FD2S and CD2S drives.
| Published maximum | Sigma-7 rotary servomotors (SGM7J / SGM7A / SGM7G) | SMH Series AC Servo Motors (SMH40S-SMH… |
|---|---|---|
| Rated torque | 22.3 Nm | 48 Nm meets or exceeds |
| Peak torque | 54 Nm | — |
| Speed | 6,000 rpm | — |
| Power | 15,000 W | 7,500 W |
A complete AGV drive wheel combining servo motor, drive, reducer, brake and polyurethane tyre in one unit on 24-60 VDC with CANopen. Three published sizes (150, 165 and 180 mm wheels) give 3.6-40 Nm rated and up to 99 Nm peak at the wheel, for mobile robots carrying up to 1 tonne.
| Published maximum | Sigma-7 rotary servomotors (SGM7J / SGM7A / SGM7G) | iWMC Integrated Servo Wheel |
|---|---|---|
| Rated torque | 22.3 Nm | 40 Nm meets or exceeds |
| Peak torque | 54 Nm | 99 Nm meets or exceeds |
| Speed | 6,000 rpm | — |
| Power | 15,000 W | — |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
Other ac servo motor series
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