Perfect New Sigma-7 Rotary Servo Motor YASKAWA SGM7A-02A6A2E Good Performance for Industrial Machinery

The Yaskawa SGM7A-02A6A2E is a compact Sigma-7 (SGM7A) rotary brushless AC servomotor designed for high-speed, low-inertia motion where positioning quality and machine uptime matter more than oversized torque. In the Sigma-7 lineup, the SGM7A family targets fast response and agile acceleration, and this specific model adds two features that strongly shape how it gets used in real machines: an oil seal and a 24 VDC holding brake.

At a glance, this motor is a 200 V class, 0.2 kW unit with a 24-bit batteryless absolute encoder, a straight shaft without key, and a torque profile that fits common packaging, assembly, inspection, and light material-handling axes—especially vertical or “gravity-sensitive” mechanisms that benefit from a holding brake.

Built for dynamic axes: torque, speed, and inertia in practical balance

Small servos often live on axes that start and stop constantly: feeders, index tables, compact belt stages, and short-stroke screw drives. In those applications, it is not just peak torque that matters; it is how quickly the motor can change speed and settle without exciting the mechanics.

For the SGM7A-02A6A2E, Yaskawa specifies:

• Rated torque: 0.637 N·m

• Instantaneous maximum torque: 2.23 N·m

• Rated speed: 3000 min⁻¹

• Maximum speed: 6000 min⁻¹

• Motor moment of inertia: 0.14 × 10⁻⁴ kg·m²

That combination is well suited for fast indexing and responsive control on light-to-moderate loads. The inertia figure is especially useful during sizing: it helps you estimate the inertia ratio after gearbox or pulley reflection, and it gives you a reality check for how “snappy” the axis can feel once the mechanics are attached. Yaskawa also lists an allowable load moment of inertia of 30× for this model, indicating it is intended to tolerate a reasonable range of reflected inertias when properly tuned.

Encoder and feedback: 24-bit, batteryless absolute for repeatable positioning

The motor is equipped with a 24-bit high-resolution encoder and is specified as batteryless absolute. Practically, that pairing supports three things OEMs and maintenance teams care about:

1. Fine positioning granularity and smoother low-speed motion (helpful for inspection, dispensing, and precision indexing).

2. Cleaner recovery after power cycles, because absolute position information is preserved without relying on a battery-backed scheme.

3. Reduced maintenance overhead, since there is no encoder battery lifecycle to manage.

Yaskawa’s Sigma-7 materials describe the 24-bit absolute encoder as providing 16 million pulses per revolution, positioning it as a “next level” feedback option for accuracy-focused motion.

The “E” advantage: oil seal + holding brake changes where you can safely use it

Two built-in features make SGM7A-02A6A2E notably different from a plain-shaft, no-option motor.

Oil seal: better tolerance around lubricated or contaminated mechanisms

The motor is specified “with oil seal”. In typical machine design, an oil seal at the shaft interface helps reduce the risk of contaminants migrating along the shaft path—particularly in applications involving gearboxes, greased couplings, belt drives near lubricated bearings, or environments with fine particulate. It is not a substitute for proper guarding and enclosure design, but it is a practical durability feature for machines that operate in less-than-laboratory conditions.

Holding brake (24 VDC): for holding, not for stopping

This model includes a holding brake (24 VDC). That is most valuable on:

• Vertical Z-axes or lift mechanisms (to reduce the risk of load drop when power is removed)

• Screw-driven stages that must hold position at rest

• Index tables or tooling axes that must remain fixed during e-stop sequences (after controlled deceleration)

One important engineering note: Yaskawa’s brake guidance emphasizes that the brake in a servo motor is a de-energization brake (it must be energized to release), and it is used only to hold the servomotor and cannot be used for stopping. The holding brake should be applied only when the motor is already stopped. This matters for reliability: using the brake as a dynamic stop device accelerates wear and can create inconsistent stopping behavior.

The same brake note also describes that brake control is typically handled through an external relay or solid-state relay driven by the SERVOPACK brake output, with attention to surge suppression and timing parameters. In other words: the brake is part of the system, not just the motor, and correct wiring/timing prevents nuisance overload alarms and mechanical shock.

Mechanical integration: compact frame, plain shaft, and modern cabinet-friendly systems

Mechanically, the SGM7A-02A6A2E is built around a compact face and a smooth shaft interface:

• Shaft end: straight without key

• Flange dimension (LC): 60 mm; flange diameter (LA): 70 mm

• Shaft diameter (S): 14 mm; shaft length (Q): 30 mm

• Dimensions (H × W × D): 74.7 × 60 × 148 mm

• Weight: 1.5 kg

A straight, non-keyed shaft is commonly paired with clamp-style couplings that can provide low backlash and clean torsional behavior when installed correctly. With the addition of the holding brake, this motor becomes a strong candidate for compact vertical modules where the coupling choice and brake timing are both part of the performance story.

On the system side, Sigma-7 is designed for fast commissioning and high throughput. Yaskawa’s Sigma-7 brochure highlights features such as simplified commissioning, auto-tuning, high performance density, and servo drive capabilities (for example, speed loop bandwidth figures and general productivity claims) that support high-speed motion systems when the entire axis is engineered and tuned as a unit.

Typical applications for SGM7A-02A6A2E

This motor is particularly well matched to:

• Vertical Z axes in pick-and-place, carton handling, and assembly tooling (holding brake supports safe “stop and hold” behavior)

• Compact screw-driven stages that must hold position under load

• Indexers and rotary tooling where short bursts of peak torque are common

• Packaging and inspection machinery that benefits from fine encoder resolution and consistent settling

• Light conveyors and feeders that demand fast acceleration and repeatable positioning

Because it includes both an oil seal and a holding brake, it is also a sensible option in machines that run near lubricated components or in environments where sealing helps extend service life.

Key Specifications Table (SGM7A-02A6A2E)

Final notes for installation and reliability

If you are integrating SGM7A-02A6A2E into a vertical axis, treat the brake as a holding device and design your control sequence so the axis is decelerated to a stop before the brake engages. Yaskawa explicitly cautions that the brake is not intended for stopping and should only hold a motor that is already stopped. Combine that with correct coupling selection for a straight shaft, and you get a compact servo axis that is fast, repeatable, and much less likely to surprise you during power events.