QDD Robot Actuators

Integrated quasi-direct-drive actuator modules for dynamic robot joints that need high torque density, low reflected inertia, and backdrivable behavior.

Target Buyer:Best for robotics teams comparing QDD joint modules for prototype validation and later batch production.

Integrated 36 Nm QDD actuator module for high-torque robot joints

Capability Highlights

Low-ratio planetary transmission direction for responsive joints
High-torque BLDC/PMSM motor integration for compact robot axes
OEM options for winding, shaft, encoder, connector, housing, and cable routing

Typical Applications

Quadruped hip, knee, and ankle joints
Humanoid lower-limb prototypes
Research robots and mobile manipulators

Engineering Focus

Continuous torque, peak torque, speed, voltage, and duty cycle envelope
Gear ratio, reflected inertia, friction, and backdrive torque target
Encoder, communication bus, wiring, mounting, and thermal path

Buyer Decision Summary

A buyer should leave this page with a shortlist decision: whether this actuator family deserves a sample review, what must be measured first, and which constraints must be fixed before price comparison.

Best Evidence

Start with torque class and connect it to the real robot duty cycle instead of reviewing catalog values alone.

Primary Risk

Peak torque is selected without checking repeated gait loads

Next Buyer Action

Prepare robot type, joint location, and target load case plus validation targets before requesting samples or commercial terms.

How to Evaluate This Actuator Family

Use this page to turn a product family into a shortlist decision. The useful comparison is not one headline torque number; it is how the actuator behaves inside the real robot joint.

Torque class

14–60 Nm continuous, 36–200 Nm peak across families

Separates arm, hip, knee, ankle, and lab platform requirements before samples are selected.

Reduction ratio

6:1–10:1 planetary, reflected inertia 0.03–0.08 kg·m²

Controls speed, backdrivability, reflected inertia, impact response, and control feel.

Thermal duty

Winding limit 120°C, housing 80°C at 30-min gait soak

Dynamic robots often fail on repeated duty cycle rather than one peak torque number.

Sample Validation Plan

Before a batch decision, buyers should define the evidence expected from sample review and internal testing.

Signal to Check	Review Basis	Evidence to Ask For
Torque class	14–60 Nm continuous, 36–200 Nm peak across families	Review RMS torque, duty cycle, ambient temperature, and heat path before sample release.
Reduction ratio	6:1–10:1 planetary, reflected inertia 0.03–0.08 kg·m²	Check gear ratio, friction, backdrive torque, encoder resolution, and controller bandwidth together.
Thermal duty	Winding limit 120°C, housing 80°C at 30-min gait soak	Review RMS torque, duty cycle, ambient temperature, and heat path before sample release.

Acceptance Thresholds to Define

Define measurable pass/fail thresholds before the sample arrives. This prevents a subjective review where one team checks torque, another checks packaging, and nobody records whether the actuator can move toward pilot build.

Torque class: Separates arm, hip, knee, ankle, and lab platform requirements before samples are selected.
Reduction ratio: Controls speed, backdrivability, reflected inertia, impact response, and control feel.
Thermal duty: Dynamic robots often fail on repeated duty cycle rather than one peak torque number.

When This Family May Not Fit

A QDD actuator family is valuable only when the application needs its trade-offs. The same module can be a poor fit when the surrounding joint requirements point in a different direction.

Peak torque is selected without checking repeated gait loads: Review RMS torque, duty cycle, ambient temperature, and heat path before sample release.
The joint is too stiff or high-inertia for torque control: Check gear ratio, friction, backdrive torque, encoder resolution, and controller bandwidth together.

Buyer Inputs That Improve the First Reply

A complete first inquiry shortens review loops because engineering can separate fixed constraints from adjustable actuator choices.

Fixed Constraints

Robot type, joint location, and target load case
Continuous torque, peak torque, speed, voltage, and current limit
Required gear ratio or maximum reflected inertia

Review Targets

Encoder, brake, controller, and communication preference
Mechanical envelope, shaft/flange drawing, or STEP reference
Prototype quantity, annual forecast, destination, and timeline

Key Evaluation Matrix

Metric	Typical Range	Why It Matters
Torque class	14–60 Nm continuous, 36–200 Nm peak across families	Separates arm, hip, knee, ankle, and lab platform requirements before samples are selected.
Reduction ratio	6:1–10:1 planetary, reflected inertia 0.03–0.08 kg·m²	Controls speed, backdrivability, reflected inertia, impact response, and control feel.
Thermal duty	Winding limit 120°C, housing 80°C at 30-min gait soak	Dynamic robots often fail on repeated duty cycle rather than one peak torque number.

Engineering Documents by RFQ

Document packages are shared after the actuator family, joint envelope, and program context are clear. Ask for available datasheets, drawings, CAD files, torque-speed notes, compliance records, or test reports during RFQ review.

Document	Status	RFQ Input Needed
Datasheet PDF	Available by actuator class review	Torque, speed, voltage, and quantity target
2D drawing	Available by mechanical envelope review	Shaft, flange, bolt pattern, and connector constraints
3D CAD / STEP / IGES	Shared when applicable after RFQ context	Joint envelope, mounting direction, and confidentiality needs
Torque-speed / thermal envelope	Program-dependent review	Duty cycle, ambient temperature, current limit, and mounting heat path
Compliance or test reports	Requestable per program when available	Destination market and required document list

How to Request CAD / Datasheets Compliance Document Scope

RFQ Checklist

Robot type, joint location, and target load case
Continuous torque, peak torque, speed, voltage, and current limit
Required gear ratio or maximum reflected inertia
Encoder, brake, controller, and communication preference
Mechanical envelope, shaft/flange drawing, or STEP reference
Prototype quantity, annual forecast, destination, and timeline

Risk Controls

Peak torque is selected without checking repeated gait loads: Review RMS torque, duty cycle, ambient temperature, and heat path before sample release.
The joint is too stiff or high-inertia for torque control: Check gear ratio, friction, backdrive torque, encoder resolution, and controller bandwidth together.

Product Gallery

Integrated 14 Nm QDD actuator module for compact robot joints

Compact robot joint actuator module for QDD robot platforms

Brushless robot joint module for compact QDD actuator programs

22 Nm planetary robot joint module for low-ratio actuator validation

Buyer FAQ

Can a QDD actuator be customized for a specific robot joint?

Yes. Gear ratio, winding, shaft, housing, encoder, connector, cable routing, brake, and interface choices can be reviewed for OEM programs.

What makes QDD different from high-ratio harmonic joints?

QDD uses lower reduction and more motor torque to preserve backdrivability, dynamic response, and lower reflected inertia where the robot application needs it.

Related Resources

Inquiry Email

[email protected]

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Include robot type, joint location, torque/speed/voltage targets, quantity, and destination.

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+86 18857971991

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Send QDD actuator specs, STEP files, or actuator references for engineering review.