---
title: "LPA-20 (Low Profile Rotary Actuator) by Harmonic Drive LLC: specs, torque and price"
description: "Harmonic / Precision actuator from Harmonic Drive LLC (Japan). Peak torque 57 Nm, rated 16.9 Nm, weight 1400 g, torque density 40.7 Nm/kg, price quote only."
canonical: https://getactuators.com/actuators/harmonic-drive-lpa-20
last-updated: 2026-09-26T20:29:50.000Z
---
# LPA-20 (Low Profile Rotary Actuator) by Harmonic Drive LLC

> Harmonic / Precision actuator from Harmonic Drive LLC (Japan). Peak torque 57 Nm, rated 16.9 Nm, weight 1400 g, torque density 40.7 Nm/kg, price quote only.

## Specifications

| Spec | Value |
| --- | --- |
| Category | Harmonic / Precision |
| Peak torque | 57 Nm |
| Rated torque | 16.9 Nm |
| Max speed | n/a |
| Gear ratio | 51:1-101:1 |
| Weight | 1400 g |
| Torque density | 40.7 Nm/kg |
| Price | quote only |
| Price per Nm | n/a |
| Backdrivable | no |
| Backlash | 0 arcmin |
| Voltage | 48 V |
| Peak current | n/a |
| Communication | CAN, EtherCAT |
| Control modes | position, velocity, torque |
| Encoder | dual absolute encoders |
| Integrated driver | yes |
| Availability | in production |
| Data status | verified against sources |

## Use cases

- humanoid joint
- cobot joint
- robot arm
- surgical robotics

## Notes

Low-profile integrated servo actuator aimed at humanoid/cobot joints and surgical robotics. Combines zero-backlash Harmonic Drive gearing, a brushless servomotor, brake, dual absolute encoders and an integrated servo drive (CANopen/EtherCAT). Gear ratios 51/81/101:1. Continuous torque 6.5 to 16.9 N·m and maximum (peak) torque 34 to 57 N·m depending on ratio; recorded values are the top-of-range (101:1) figures. Weight about 1.4 kg. Rated supply voltage 48 VDC (confirmed via distributor listing). torque\_density computed from peak 57 N·m over 1.4 kg. Repeatability not published in accessible sources, so left null. Quote-only pricing.

## Sources

- <https://www.harmonicdrive.net/products/integrated-actuators/integrated-actuators/lpa-integrated-servo-drive>
- <https://www.harmonicdrive.net/_hd/Content/documents1/Group%20Integrated%20Brochure.pdf>
- <https://humanoidroboticstechnology.com/company/harmonic-drive-llc/lpa-20-integrated-servo-actuator/>
- <https://www.directindustry.es/prod/harmonic-drive-llc/product-4567321-2832039.html>
- <https://www.roboticstomorrow.com/news/2026/07/06/harmonic-drive-advances-surgical-robotics-supply-with-innovative-lpa-20-compact-actuator-control-component/26804>

## Similar Harmonic / Precision actuators

- [FHA-14C-100 (FHA-C Mini) (Harmonic Drive LLC)](https://getactuators.com/actuators/harmonic-drive-fha-14c-100): 17 Nm/kg
- [SHA-CG series (SHA-CG Hollow Shaft Actuator) (Harmonic Drive LLC)](https://getactuators.com/actuators/harmonic-drive-sha-cg): n/a
- [CHA series (Hollow Shaft Servo Actuator) (Harmonic Drive (Harmonic Drive SE / LLC))](https://getactuators.com/actuators/harmonic-drive-cha-series): n/a
- [LHS series (Harmonic Drive strain-wave reducer) (Leaderdrive (Suzhou Leader Harmonic Drive))](https://getactuators.com/actuators/leaderdrive-lhs): n/a
- [LHD series (hollow-shaft harmonic reducer) (Leaderdrive (Suzhou Leader Harmonic Drive))](https://getactuators.com/actuators/leaderdrive-lhd): n/a

## Machine-readable

- JSON: https://getactuators.com/api/v1/actuators/harmonic-drive-lpa-20
- Catalog index for agents: https://getactuators.com/llms.txt