Mitsubishi HC-SF52K AC Servo Motor — HC-SF Series 500W Keyed Shaft Motor

A Motor That Earns Its Place on the Machine Floor

The Mitsubishi HC-SF52K sits in a category that machine builders and maintenance engineers both appreciate — compact enough to fit demanding axis configurations, powerful enough to handle real workloads, and straightforward enough to integrate into existing MELSERVO systems without headaches. It's part of Mitsubishi's HC-SF series, a line designed around medium-inertia, medium-capacity applications where stability across the speed range matters as much as peak performance.

At its core, this is a 0.5 kW (500 W) AC brushless servo motor built for three-phase operation at 126V AC, turning at a rated speed of 2,000 RPM. The encoder fitted to this unit delivers 16,384 pulses per revolution, giving the servo system the resolution it needs for smooth, accurate positioning. The "K" in the model designation tells you the shaft is a keyed cylindrical type at φ14 mm — a configuration that suits direct coupling to ballscrews, gearboxes, and any driven component where a positive mechanical lock is preferred over relying on clamping force alone.

Technical Specifications

What the HC-SF Series Is Built For

Mitsubishi engineered the HC-SF line with medium-inertia characteristics — which places it in a useful middle ground between the nimble low-inertia motors used in high-cycle, short-stroke applications and the heavier high-inertia motors suited to large, continuous-load tasks. That balance makes the HC-SF52K a natural fit for:

• CNC machining centers — particularly feed axis drives that need smooth movement under variable cutting loads
• Robotic arms and automated handling systems — where the combination of torque density and compact size keeps the overall arm geometry manageable
• X-Y positioning tables — where bidirectional accuracy and repeatability at 2,000 RPM define the quality of the output
• Transmission machinery and conveyance systems — applications where steady, predictable torque delivery matters more than extreme acceleration

The motor's IP65 rating gives it meaningful protection against dust ingress and low-pressure water jets — useful for installations in machine enclosures where coolant mist is a routine environmental factor rather than an edge case.

Drive Compatibility and System Integration

The HC-SF52K is designed to pair with Mitsubishi MR-J2 and MR-H series servo drives. These amplifiers handle position, speed, and torque control loops, with the motor's encoder providing the feedback signal that closes the loop. The combination is well-documented, and parameters for the HC-SF series are supported natively in Mitsubishi's servo configuration software.

If you're replacing an existing motor on a machine already running MR-J2 or MR-H amplifiers, the HC-SF52K slots into that ecosystem without requiring amplifier changes or extensive parameter tuning — assuming the shaft configuration and mounting flange match the original installation.

One thing worth noting: the HC-SF series is older than the HC-SFS series. Both share similar output ratings and flange dimensions, but they are not interchangeable without verifying encoder compatibility and drive parameter settings. Don't assume a direct swap without cross-checking first.

On the Shaft Configuration

The keyed shaft is the defining hardware detail of this variant. A keyway cut into the shaft engages a corresponding slot in the coupling or hub, creating a positive interlock that transmits torque mechanically rather than through friction. Under dynamic or reversing loads — common in feed axis and robotic applications — this eliminates the micro-slip that can degrade positional accuracy over time in friction-only couplings. The φ14 mm diameter is a standard size that's well-supported by coupling manufacturers, making installation hardware easy to source.

Frequently Asked Questions

Q1: What servo drive does the HC-SF52K work with?

A: This motor is designed for use with Mitsubishi MR-J2 and MR-H series servo amplifiers. It is not directly compatible with newer MR-J3 or MR-J4 drives without an interface adapter, as the encoder signal type differs between generations.

Q2: Does the HC-SF52K have a built-in electromagnetic brake?

A: No. This variant does not include a brake. If your application requires power-off position holding — such as a vertical axis — you would need to select the brake-equipped version, which carries a "B" designation in the model suffix (e.g., HC-SF52BK).

Q3: What is the difference between the HC-SF52K and HC-SFS52K?

A: Both are 0.5 kW motors with similar torque ratings, but they belong to different generations of the MELSERVO lineup. The HC-SF series pairs with MR-J2 / MR-H drives using a 14-bit encoder; the HC-SFS series is from the newer J2S generation with a 17-bit absolute encoder (131,072 ppr). They share similar flange dimensions but are not drive-compatible with each other without parameter changes.

Q4: What does IP65 protection mean for day-to-day use?

A: IP65 means the motor is fully protected against dust and against water jets from any direction at low pressure. It's well-suited for use inside CNC machine enclosures where coolant splash and mist are common, though it should not be submerged.

Q5: Can this motor be repaired if the encoder fails?

A: Yes. Encoder replacement is one of the most common service items on the HC-SF series. Qualified servo repair shops can replace the encoder assembly and recalibrate the motor. For a 0.5 kW motor, repair is generally cost-effective compared to full replacement, especially when the winding and mechanical components are otherwise in good condition.

The Mitsubishi HC-SF52K is a legacy servo motor. Confirm drive compatibility, shaft configuration, and flange dimensions against your machine's original specifications before ordering.