Harmonic actuator
Harmonic Drive FHA-C hollow-shaft servo actuators
A slim hollow-shaft servo actuator that combines a strain wave gear, AC servo motor and encoder in one flat unit, for direct-drive-style rotary positioning.
Key specifications
| Bore (max) | 45 mm |
|---|---|
| Peak torque (max) | 820 Nm |
| Speed (max) | 96 rpm |
| Supply | 200 VAC (100 VAC option sizes 17/25/32; 24 VDC option size 17) |
| Ratio | 50–160:1 |
| Backlash (max) | 0 arcmin |
| Sizes | 17, 25, 32, 40 |
Summarised in our own words from Harmonic Drive SE / Harmonic Drive LLC's published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2
Notes on this data
Maximum torque is 820 Nm (FHA-40C-160) per Harmonic Drive LLC; Harmonic Drive SE gives 39–823 Nm. Speed 96 rpm is FHA-17C at 50:1. The hollow shaft is 18–45 mm per SE. 'Zero backlash' is stated; one-way positioning accuracy is 30–60 arcsec. No rated torque or IP rating is on the page. FHA-C Mini (sizes 8–14) and FHA-C-PR/-H variants also exist.
Specify Motion is not affiliated with Harmonic Drive SE / Harmonic Drive LLC. Harmonic Drive and FHA-C hollow-shaft servo actuators 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 Harmonic Drive 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.
Hollow-shaft harmonic servo actuator: strain-wave gearing, motor, encoder and brake in one unit, run from a separate servo drive. Six frame sizes, from 48 VDC to 220 VAC.
| Published maximum | FHA-C hollow-shaft servo actuators | MAH |
|---|---|---|
| Peak torque | 820 Nm | 800 Nm |
| Rated torque | — | 557 Nm |
| Speed | 96 rpm | 125 rpm meets or exceeds |
Large-bore version of the harmonic actuator with a frameless 16-pole motor, giving a much bigger through-hole for cabling. Two sizes.
| Published maximum | FHA-C hollow-shaft servo actuators | MAT |
|---|---|---|
| Peak torque | 820 Nm | 800 Nm |
| Rated torque | — | 557 Nm |
| Speed | 96 rpm | 102 rpm meets or exceeds |
Harmonic actuator with an integrated German-made Synapticon Circulo servo drive on EtherCAT, with STO and optional FSoE functional safety.
| Published maximum | FHA-C hollow-shaft servo actuators | MGM |
|---|---|---|
| Peak torque | 820 Nm | 459 Nm |
| Rated torque | — | 267 Nm |
| Speed | 96 rpm | 108 rpm meets or exceeds |
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 harmonic actuator series
Spec builder
Specify what you need instead of FHA-C hollow-shaft servo actuators
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Let our experienced engineers do the hard work for you
Tell us how you use the Harmonic Drive FHA-C hollow-shaft servo actuators: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.