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AC servo motor

SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic) AC servo motor

Highly dynamic synchronous servomotors in seven sizes (40 to 112) with standstill torques from 0.5 to 95 Nm and dynamic limit torques up to 320 Nm on the CMP112 (series maximum).

Key specifications

Peak torque (max)320 Nm
Standstill torque0.5–95 Nm
Speed (max)6,000 rpm
Sizes40, 50, 63, 71, 80, 100, 112
Speed classes3000/4500/6000 rpm (40-63); 2000/3000/4500/6000 rpm (71-80); 2000/3000/4500 rpm (100-112)
BrakeBY holding brake option on CMP112

Summarised in our own words from SEW-EURODRIVE GmbH & Co KG's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1

Notes on this data

31 torque gradations. Explosion-protected CMP variants also exist (separate page). Encoder, IP and temperature data not stated on the page read.

Specify Motion is not affiliated with SEW-EURODRIVE GmbH & Co KG. SEW-EURODRIVE and CMP.. synchronous servomotors (High Dynamic) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

Typical applications

Highly dynamic positioning axesPackaging machinesHandling systems

Alternatives that meet or exceed these figures

Engineers often come to us with a SEW-EURODRIVE 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.

Meets or exceeds on 1 of 3 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 maximumCMP.. synchronous servomotors (High Dynamic)SMK Series AC Servo Motors (SMK40S/60S…
Rated torque95 Nm47.8 Nm
Peak torque320 Nm119.5 Nm
Speed6,000 rpm6,000 rpm meets or exceeds
Power—7,500 W
View series →

Leadshine's AC servo motors for the EL8/EL7/EL6 drives: ELM1 is the economy line and ELM2 the general-purpose line, both with 23-bit absolute encoders, IP65/IP67 sealing and up to 3.5x overload. The catalogue extends ELM2M to 22 kW and previews a 26-bit ELM3.

View ELM1 / ELM2 AC Servo Motors →
Meets or exceeds on 1 of 3 figures

Leadshine low-voltage PMSM servo motors from a 25 mm 33 W unit up to a 130 mm 2 kW unit, wound for 24-60 V DC buses. Fully published data covers torque to 6.4 Nm rated / 16 Nm peak, 17-bit absolute or 2500 ppr incremental encoders and IP65. Designed for ELD2, 2ELD2 and ELD3 drives.

Published maximumCMP.. synchronous servomotors (High Dynamic)ELVM Series Low-Voltage DC Servo Motors
Rated torque95 Nm6.4 Nm
Peak torque320 Nm16 Nm
Speed6,000 rpm6,000 rpm meets or exceeds
Power—2,000 W
View ELVM Series Low-Voltage DC Servo Motors →

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.

What an AC servo motor is

An AC servo motor is a permanent-magnet synchronous motor designed for closed-loop control of position, speed and torque. A wound stator is driven by a servo drive with sinusoidal three-phase current, while magnets on the rotor follow the rotating field. A high-resolution encoder or resolver on the shaft feeds position back to the drive, which adjusts current many thousands of times a second. The result is precise, dynamic motion with high peak torque, typically about three times the continuous rating for short periods.

When engineers choose an AC servo motor

Choose an AC servo for machine axes needing fast, accurate motion under varying loads, such as packaging, robotics, machine tools and printing. Compared with steppers, servos keep torque at high speed and cannot silently lose position. The trade-offs are cost and set-up: a servo needs a matched drive, feedback and tuning. For simple, low-speed indexing with a steady load, a stepper may be cheaper. For very low speeds and high torque, a gearbox or direct-drive motor may be needed.

How to specify the SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic)

Send these with your enquiry and an engineer can confirm the right CMP.. synchronous servomotors (High Dynamic) variant or an equivalent:

  • Continuous and peak torque (Nm)
  • Rated and maximum speed (rpm)
  • Load inertia and inertia ratio
  • Supply voltage: 230 V single-phase or 400 V three-phase
  • Feedback: incremental or absolute encoder, resolution (bits)
  • Holding brake, IP code and shaft options
  • Flange size and mounting (mm)

Common mistakes to avoid

  • Sizing on peak torque without checking RMS torque over the cycle
  • Ignoring load-to-motor inertia ratio, which makes tuning hard
  • Forgetting the brake is for holding, not dynamic stopping
  • Using a motor and drive pair that the supplier has not matched

SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic): frequently asked questions

What is the SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic)?

Highly dynamic synchronous servomotors in seven sizes (40 to 112) with standstill torques from 0.5 to 95 Nm and dynamic limit torques up to 320 Nm on the CMP112 (series maximum). Published series figures include peak torque 320 Nm, standstill torque 95 Nm, speed 6,000 rpm. It is made by SEW-EURODRIVE GmbH & Co KG; Specify Motion can help source it or propose an equivalent.

Who makes the SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic)?

The SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic) is made by SEW-EURODRIVE (SEW-EURODRIVE GmbH & Co KG) and is listed here for engineers comparing options. Specify Motion is not affiliated with SEW-EURODRIVE GmbH & Co KG; brand names are used only to identify the product.

What is the peak torque of the SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic)?

The published series maximum peak torque is 320 Nm. Individual models and sizes in the CMP.. synchronous servomotors (High Dynamic) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.

Is there an alternative to the SEW-EURODRIVE CMP.. synchronous servomotors (High Dynamic)?

Yes. On published figures, Kinco SMK Series AC Servo Motors (SMK40S/60S/80S, SMK130G, SMK180G) and Leadshine ELM1 / ELM2 AC Servo Motors are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.

What is the inertia ratio in servo sizing?

The inertia ratio compares the load inertia reflected to the motor shaft with the motor's rotor inertia. High ratios make the axis harder to tune and slower to settle. Many engineers aim for below about 10:1, and lower for highly dynamic axes, using a gearbox to reduce reflected inertia where needed.

Do AC servo motors need an absolute encoder?

Not always. Incremental encoders need a homing routine after power-up, which is acceptable on many machines. Absolute encoders know their position at power-on, avoiding homing, which saves time and suits robots and multi-axis machines. Multi-turn absolute encoders track turns even when power is off.

Further reading: How to select a servo motor · Servo vs stepper · Servo and stepper motors

Other ac servo motor series

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