Performance Curves
Request torque-speed, efficiency, and temperature-rise data for the quoted winding and cooling condition.
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Compact Robot Joint Motors
High torque density frameless motors for cobot, humanoid, exoskeleton, and compact actuator modules.
Target Buyer:Best for robotics teams that need high torque density and fast iteration without high overseas-brand MOQ friction.
Capability Highlights
- Compact ID/OD geometry for cable pass-through and joint packaging.
- Low cogging and smooth control targets for collaborative robot motion.
- Prototype-friendly custom support for emerging robot platforms.
Typical Applications
- Cobot shoulder, elbow, wrist, and end-effector joints
- Humanoid robot hip, knee, ankle, arm, and hand modules
- Wearable robotics, exoskeleton joints, and compact servo actuators
Engineering Focus
- Match motor OD/ID to reducer, encoder, bearing, and cable routing constraints.
- Review torque ripple, inertia, and thermal rise against human-safe smoothness targets.
- Define prototype acceptance criteria before committing to joint-module tooling.
Key Evaluation Matrix
| Metric | Typical Range | Why It Matters |
|---|---|---|
| Torque density | Optimized by magnet grade, stack length, and cooling path | Directly affects robot payload, joint size, and battery/runtime tradeoffs. |
| Large ID ratio | Sized for encoder, bearing, cable, or reducer integration | Keeps the robot joint compact while preserving internal routing. |
| Low cogging behavior | Custom electromagnetic design target | Supports smooth motion and force-control behavior in robot applications. |
Baseline Parametric Fields for RFQ Review
Final values depend on motor size, winding, thermal path, and custom scope. Include these fields in the first RFQ so engineering can return a usable model or custom design path.
| Parameter | Unit | RFQ Note |
|---|---|---|
| Rated voltage | VDC | Match bus voltage and servo drive current limit. |
| Continuous torque | N·m | State thermal condition and duty cycle. |
| Peak torque | N·m | Define duration and repetition rate. |
| Rated / maximum speed | rpm | Include control and mechanical limits. |
| Torque constant Kt | N·m/Arms | Used for drive sizing and current estimate. |
| Motor constant Km | N·m/√W | Supports efficiency and heat comparison. |
| Back EMF constant | V/krpm | Must match speed and voltage ceiling. |
| Resistance / inductance | Ω / mH | Needed for drive tuning and thermal model. |
| Rotor inertia | kg·cm² | Affects acceleration and control response. |
| Weight / insulation class | kg / class | Supports payload, heat, and safety review. |
| Torque ripple | % or N·m | Critical for robotics, gimbals, and precision axes. |
CAD & Datasheets
2D drawings, datasheets, and STEP/IGES files are shared when the model family and project scope are clear.
Mechanical Integration
Review stator mounting, rotor clamping, air gap, lead wires, and sensor compatibility before sample approval.
Exact Datasheet Fields to Request Before Sample Approval
The table below is not a claim that every configuration has a fixed public catalog value. It is the data package an engineering buyer should request for the selected winding, frame size, and cooling basis before approving samples or CAD release.
| Data Group | Fields | Why Buyers Need It |
|---|---|---|
| Electrical constants | Kt, Km, back EMF constant, phase resistance, phase inductance | Confirms winding fit with bus voltage, drive current, speed ceiling, and tuning assumptions. |
| Mechanical data | OD, ID, stack length, rotor inertia, mass, mounting references, lead exit | Prevents CAD mismatch and helps the buyer validate acceleration and package constraints. |
| Thermal basis | Continuous rating condition, ambient temperature, housing/cooling assumption, insulation class | Separates sustainable torque from short-duration peak torque and avoids heat-path overclaims. |
| Performance curves | Torque-speed curve, efficiency notes, temperature-rise basis, peak torque duration | Lets the buyer compare real operating duty instead of relying on one headline torque number. |
| Inspection records | Resistance, back EMF, insulation / hi-pot, visual check, outgoing record format | Supports sample acceptance, supplier qualification, and repeat-order traceability. |
RFQ Checklist
- Target outside diameter, inside diameter, stack length, and available mounting envelope.
- Continuous torque, peak torque, target speed, duty cycle, and expected motion profile.
- DC bus voltage, current limit, cooling method, ambient temperature, and insulation requirement.
- Lead wire, connector, Hall, encoder, resolver, or bare motor integration requirements.
- Prototype quantity, annual forecast, target delivery country, and requested timeline.
Risk Controls
- Joint package changes during prototype iteration: Use revision-controlled OD, ID, stack, and mounting drawings before each sample round.
- Drive electronics and motor winding are mismatched: Share bus voltage, current limit, control loop target, and drive model at RFQ stage.
Product Gallery
Buyer FAQ
Can you support low-MOQ robot prototype projects?
Prototype quantities can be discussed for qualified OEM projects. Send your joint envelope, torque-speed duty, and timeline for review.
Can the motor fit a harmonic or strain-wave reducer?
Yes, but reducer size, mounting stack, bearing layout, and cable routing need to be reviewed together with the motor geometry.
Related Resources
Inquiry Email
Include target torque/speed, quantity, and delivery location.