Good Price Brand New Sigma-7 Rotary AC Servo Motor YASKAWA SGM7A-08A6A61 With High Quality

The Yaskawa SGM7A-08A6A61 is a Sigma-7 (SGM7A) rotary AC servomotor designed for high-response motion control in industrial automation. It targets the “fast, precise, compact” space where machines need clean acceleration, stable settling, and repeatable positioning without stepping up to a heavier, higher-inertia motor family. Yaskawa positions the SGM7A series around a 24-bit high-resolution encoder, high efficiency with low heat generation, potential downsizing, Sigma-5 flange compatibility, and low inertia / high speed behavior.

What makes the SGM7A-08A6A61 variant specifically valuable is its shaft style: straight shaft with key and tap. Compared with a keyless shaft version, this configuration is often chosen when the mechanical coupling must be robust under repeated reversals, quick accelerations, or higher shock tolerance requirements—think pulleys, sprockets, timing-belt drives, or compact gearboxes that are easier to standardize around keyed hubs. The tapped shaft end also improves serviceability in many field scenarios because it supports secure retention and predictable disassembly practices (for example, when a hub needs to be pulled without damaging bearings or couplings).

A practical 0.75 kW class for mid-size axes

This motor is rated at 0.75 kW on a 200 V supply system. In many real machines, that power tier is where “small-axis servo” ends and “main motion module” begins: strong enough for demanding indexing, synchronized transport, and compact rotary tooling, while still compact enough to keep moving mass low and enclosure heat manageable.

The core torque and speed ratings are well suited to high-cycle automation:

• Rated torque: 2.39 N·m

• Instantaneous maximum torque: 8.36 N·m

• Rated speed: 3000 min⁻¹

• Maximum speed: 6000 min⁻¹

That peak-to-rated torque headroom matters. It gives the axis enough “burst authority” to handle acceleration ramps, short dwell times, quick direction changes, and transient disturbances (like product variation, friction changes, or minor misalignment) without oversizing the motor. For machine builders, it also increases tuning flexibility: you can tune for smoothness and stability while preserving enough peak torque capacity for real-world variance.

Inertia data that helps tuning (and prevents surprises)

Servo performance is not only about torque—it’s about how the motor, load, transmission, and structure behave together. Yaskawa provides two data points that are particularly useful during axis design and tuning:

• Motor moment of inertia: 0.776 × 10⁻⁴ kg·m²

• Allowable load moment of inertia: 20 times

These values help you estimate inertia ratio after gear reduction or belt reflection and anticipate how “snappy” the axis can be without exciting mechanical resonances. In general, the SGM7A low-inertia philosophy is chosen when you want fast response and short settling times—provided the mechanics are reasonably stiff and the transmission is selected sensibly. Yaskawa explicitly frames the SGM7A family around low inertia and high speed.

24-bit batteryless absolute encoder: precision with lower maintenance burden

SGM7A-08A6A61 includes a 24-bit encoder with batteryless absolute type feedback. From a machine lifecycle point of view, this is a quiet upgrade over older architectures. Absolute feedback improves restart behavior and reduces dependence on repeated homing cycles (subject to how the overall motion system is designed), and “batteryless” reduces the maintenance overhead and failure mode associated with encoder batteries.

For applications that are sensitive to low-speed smoothness or require consistent positioning across long production runs, high-resolution feedback is also a practical quality factor: it improves the controller’s ability to regulate motion cleanly and reject disturbances without hunting.

Keyed and tapped shaft: why it is often chosen in production machines

The straight shaft with key and tap on this model is not just a mechanical footnote; it shapes how the motor integrates into a machine.

Common reasons OEMs choose a keyed/tapped shaft:

1. Standardization with existing hubs and pulleys. Many machine designs already use keyed hubs for timing pulleys, sprockets, and compact gearheads. A keyed shaft aligns naturally with those standards.

2. Resistance to micro-slip under reversals. In aggressive indexing or reversing duty cycles, a keyed interface can provide additional security when torque direction changes rapidly (the coupling still must be correctly fitted and tightened, but the interface is less dependent on friction alone).

3. Service-friendly disassembly. The tap can support controlled retention or pulling methods, reducing the risk of improvised removal techniques that damage bearings or housings.

In short, SGM7A-08A6A61 is a strong choice when you want Sigma-7 dynamics but your mechanical design is “keyed-hub first.”

Compact envelope and mechanical dimensions

Despite its 0.75 kW rating, the motor remains compact:

• Dimensions (H × W × D): 94.7 × 80 × 145 mm

• Weight: 2.3 kg

• Flange dimension (LC): 80 mm; Flange diameter (LA): 90 mm

• Shaft diameter (S): 19 mm; Shaft length (Q): 40 mm

This size class is widely used in packaging and assembly modules where the motor must fit inside guarded frames, compact rotary stations, or multi-axis machine heads.

Options and when to choose a different variant

The SGM7A-08A6A61 is listed as “without options.” That usually means no holding brake and no additional shaft sealing options in this exact code. This is typically ideal for horizontal axes and many rotary mechanisms where the axis does not need to hold a vertical load during power-off. If your design includes a gravity-loaded Z axis or a suspended load, you would typically evaluate a brake-equipped variant in the same motor family instead of adding external holding hardware. Yaskawa lists multiple option categories at the series level (including brake and sealing variants) to support those use cases.

System context: Sigma-7 servo drives and related hardware

A servo motor performs best when paired correctly with the matching drive family and feedback/cabling. On the product page for SGM7A-08A6A61, Yaskawa lists compatible Sigma-7 drive products such as SGD7S single-axis SERVOPACKs, SGD7W dual-axis SERVOPACKs, and SGD7C SERVOPACKs with built-in controller. For machine builders, this matters because it supports consistent commissioning workflows, spare parts planning, and platform standardization across multiple machines or multiple axes.

Typical applications

With its 0.75 kW rating, high peak torque, keyed/tapped shaft, and batteryless absolute feedback, the SGM7A-08A6A61 is commonly well suited to:

• Indexing tables and rotary tooling with frequent reversals and short cycle times

• Belt-driven transport and timing-pulley axes where keyed hubs are preferred

• Compact screw-driven stages needing higher continuous torque without moving to a much larger frame

• Packaging and assembly automation requiring stable settling and high throughput

• Retrofit and modernization projects where Sigma-5 flange compatibility and compact replacement options reduce mechanical redesign effort

Technical Specifications Table — Yaskawa SGM7A-08A6A61

Closing summary

The Yaskawa SGM7A-08A6A61 is a focused, production-friendly Sigma-7 motor: 200 V, 0.75 kW, 24-bit batteryless absolute encoder, high peak torque capability, and a keyed/tapped shaft that integrates naturally with keyed pulleys, hubs, and many standard industrial couplings. It is a strong fit for mid-size axes that must move fast, settle cleanly, and run reliably—while keeping mechanical integration and service work straightforward.