A. By energy source
- Electric
- Hydraulic
- Pneumatic
- Other or emerging actuation technologies
Robotics Component Engineering Guide
Robot Actuators: Types, Architecture and Selection
Robot actuators convert electrical, hydraulic or pneumatic energy into the controlled rotary or linear movement required by a robotic system.
This guide explains actuator architectures, internal components, operating parameters, system interfaces and the evidence engineers should evaluate before selecting a robotic actuator.
What Is a Robot Actuator?
A robot actuator is the subsystem that converts an energy source and a control command into controlled mechanical motion.
A robotic actuator may contain a motor or hydraulic or pneumatic power element, a drive, transmission, encoder, brake, bearings, housing, sensors and control electronics.
Some actuators are supplied as individual motion components. Others are integrated joint modules that combine most of the motion, feedback and mechanical-support functions inside one assembly.
In summary
- The actuator produces movement.
- The motor may be only one part of the actuator.
- The transmission changes torque, speed and mechanical behaviour.
- Feedback allows closed-loop control.
- Bearings and housing carry external loads.
- Thermal limits often determine sustained performance.
- Interfaces determine whether the actuator can operate inside the robot.
is the current published international robotics vocabulary standard, although a replacement draft is under development.
What Is the Difference Between a Robot Actuator, Motor and Servo?
| Term | Meaning | Typical contents |
|---|---|---|
| Motor | Converts electrical energy into rotational mechanical energy | Rotor, stator and sometimes encoder or brake |
| Actuator | Produces controlled rotary or linear output motion | Motor or fluid power element, transmission, feedback, structure and drive |
| Servo system | Closed-loop motion-control system | Motor, drive, feedback and controller |
| Integrated joint module | Packaged actuator forming a robot joint | Motor, reducer, encoder, brake, bearings, housing and electronics |
| Drive | Controls power delivered to the motor | Power electronics and current/velocity/position control |
| Transmission | Changes speed, torque or motion form | Gear reducer, belt, screw, cable or linkage |
A motor generates motion, but a robot actuator delivers usable controlled motion to the robot structure.
The distinction matters because rated motor torque does not include the effects of transmission ratio, efficiency, bearings, thermal constraints, feedback or joint loading.
How Does a Robot Actuator Work?
- The robot controller generates a target position, velocity or torque.
- The servo drive converts that command into controlled electrical current or a hydraulic or pneumatic command.
- The motor or fluid-power element produces motion.
- A transmission may change speed, torque or motion direction.
- The output structure transfers the resulting force or torque into the robot.
- Encoders and other sensors measure the actuator state.
- The controller compares measured behaviour with the command and adjusts the actuator input.
Closed-loop control
- Target
- Controller
- Drive
- Actuator mechanics
- Output motion
Feedback → Controller
What Components Are Inside an Integrated Robot Actuator?
| Element | Function | Critical parameters |
|---|---|---|
| Motor | Generates torque and speed | Continuous torque, peak torque, speed, inertia and thermal constant |
| Reducer | Increases output torque and reduces speed | Ratio, lost motion, stiffness, efficiency and life |
| Servo drive | Controls motor current and motion | Voltage, current, bandwidth and protocol |
| Encoder | Measures motor or output position | Resolution, accuracy, latency and interface |
| Torque sensor | Measures output or joint torque | Range, accuracy, overload and bandwidth |
| Brake | Holds or stops the joint under defined conditions | Holding torque, release time and lifecycle |
| Bearings | Carry radial, axial and moment loads | Load rating, preload, stiffness and life |
| Housing | Maintains alignment and transfers heat and load | Stiffness, tolerance, material and thermal path |
| Output flange | Connects the actuator to the robot link | Bolt pattern, pilot, load limits and runout |
| Cabling/connectors | Carry power, feedback and communication | Current rating, flex life, sealing and pinout |
| Firmware | Configures and controls the module | Update rights, parameters, diagnostics and compatibility |
An integrated joint module may simplify initial integration, but it also concentrates mechanical, software and lifecycle dependency in one supplier.
is service-robot-specific, but its emphasis on clearly specified module interfaces is relevant to integrated actuator modules more broadly.
Detailed reducer parameters belong in the harmonic reducers guide. Motor-level selection is covered in the servo motors guide.
What Are the Main Types of Robot Actuators?
Actuators can be classified along three independent dimensions. These categories overlap—for example, an actuator can simultaneously be electric, rotary, geared and series-elastic.
B. By output motion
- Rotary
- Linear
- Limited-angle
- Continuously rotating
C. By mechanical architecture
- Direct drive
- Geared drive
- Integrated joint
- Series elastic
- Parallel elastic
- Variable stiffness
- Quasi-direct drive
- Cable or tendon driven
- Soft actuator
Electric Robot Actuators
Electric actuators include brushless servo systems, torque motors, integrated joint modules, electric linear actuators, screw-driven actuators, and direct-drive and geared configurations.
Strengths: Precise closed-loop control, broad supplier ecosystem, straightforward integration with digital control, high efficiency at suitable operating points, clean operation and compact integrated modules.
Constraints: Thermal limits, motor and drive sizing, gear wear and backlash, electrical power demand, cooling and cable or connector reliability.
Best-fit applications: Industrial robot arms, cobots, AMRs, service robots, humanoids, exoskeletons and inspection robots.
Do not assume electric actuators are universally more efficient or superior. Performance depends on the motion profile, actuator design and power system.
Hydraulic Robot Actuators
Hydraulic actuators generate force or torque through pressurised fluid acting on cylinders or rotary mechanisms.
Key considerations include power density, high-force applications, hydraulic supply and valves, leakage, noise, maintenance, fluid temperature, control complexity and hose routing.
Potential applications include heavy-duty manipulators, legged robots requiring high dynamic force, hazardous or remote machinery and large mobile systems. Hydraulics is not obsolete—the selection decision depends on force density, infrastructure, controllability, maintenance and operating environment.
Pneumatic Robot Actuators
Pneumatic actuators use compressed air to generate linear or rotary motion. Types include cylinders, rotary pneumatic actuators, pneumatic artificial muscles and soft-robotics actuators.
Key considerations include compliance, compressibility, air consumption, position-control limitations and infrastructure requirements.
Potential applications include simple end effectors, clamping, pick-and-place mechanisms, compliant manipulation, soft robotics and low-cost repetitive motion. Pneumatic-variable and series-elastic actuator research demonstrates that pneumatic systems can also provide controllable compliance, rather than functioning only as binary cylinders. Pneumatic variable series-elastic actuator research (PMC).
Electric vs Hydraulic vs Pneumatic Robot Actuators
| Dimension | Electric | Hydraulic | Pneumatic |
|---|---|---|---|
| Control precision | Generally strong | Strong with suitable valves and sensing | More difficult because of air compressibility |
| Force density | Moderate to high | Often high | Moderate |
| Infrastructure | Electrical power and drive | Pump, reservoir, valves and hoses | Compressor, valves and air preparation |
| Cleanliness | Generally clean | Fluid leakage must be managed | Clean at point of use, depending on air quality |
| Compliance | Architecture-dependent | Architecture-dependent | Inherent compressibility |
| Maintenance | Electrical, mechanical and cooling | Fluid, seals, pumps and hoses | Leaks, valves and air system |
| Noise | Motor, gearbox and cooling | Pump and fluid system | Exhaust and compressor |
| Integration | Often compact and modular | More distributed | Requires air infrastructure |
| Common robot use | Broad | Heavy-duty and specialised | Grippers, soft systems and simple mechanisms |
What Is the Difference Between Rotary and Linear Robot Actuators?
| Rotary actuator | Linear actuator |
|---|---|
| Produces angular motion and torque | Produces translational motion and force |
| Common in robot joints | Common in Cartesian axes, lifts and grippers |
| May use direct drive or a reducer | May use screw, belt, cylinder or linear motor |
| Main output unit: Nm and rad/s | Main output unit: N and m/s |
| Key structural issue: moment loading | Key structural issue: side loading and guidance |
Rotary actuators are generally used where the robot requires joint rotation. Linear actuators are used where a load must move along a defined straight path.
A linear actuator does not normally provide the complete guidance structure; rails, bearings or linkages may still be required to control non-axial loads.
Direct Drive, Geared, Elastic and Quasi-Direct-Drive Actuators
| Architecture | Core arrangement | Primary strengths | Primary trade-offs |
|---|---|---|---|
| Direct drive | Motor connected directly to output | Low transmission friction, low backlash and high backdrivability | Larger motor and higher current may be required |
| High-ratio geared | Motor plus high reduction | Compact motor and high output torque | Reflected inertia, friction, backlash and lower backdrivability |
| Series elastic | Elastic element in series with output | Force sensing, shock tolerance and compliant interaction | Added deflection and control-bandwidth trade-offs |
| Quasi-direct drive | High-torque motor with low-ratio transmission | Backdrivability, dynamic control and lower reflected inertia | Larger motor and thermal demands |
| Variable stiffness | Adjustable compliant element | Adaptable interaction and energy storage | Greater mechanical and control complexity |
| Cable/tendon drive | Remote actuator and flexible transmission | Low distal mass and flexible packaging | Cable stretch, routing, friction and maintenance |
Series-elastic actuators intentionally introduce compliance between the drive and output, supporting force control and physical interaction, but their design creates stiffness and bandwidth trade-offs. SEA control research (PMC). Quasi-direct-drive architectures generally combine a high-torque-density motor with a low-ratio transmission to improve backdrivability and control bandwidth. Quasi-direct-drive research (PMC).
What Actuators Are Used in Robot Arms?
Most articulated electric robot arms use rotary servo actuators at their joints. A joint actuator may combine a servo motor, drive, reducer, dual encoders, brake, bearings, housing and output flange. The exact architecture varies with payload, speed, joint location, required stiffness and interaction model.
| Joint location | Typical priority |
|---|---|
| Base and shoulder | High torque, moment capacity, stiffness and braking |
| Elbow | Torque-to-mass ratio and dynamic performance |
| Wrist | Compact size, low mass and cable routing |
| Cobot joint | Torque sensing, low friction and controlled interaction |
| Humanoid hip/knee | Torque density, impact tolerance and backdrivability |
| Hand/finger | Compact packaging, force control and low inertia |
How Do Actuator Requirements Differ by Robot Type?
| Robot category | Typical actuator priorities |
|---|---|
| Industrial arm | Accuracy, stiffness, duty cycle, repeatability and service life |
| Collaborative robot | Force control, sensing, controlled interaction and compact integration |
| AMR | Efficiency, wheel torque, braking, robustness and battery utilisation |
| Service robot | Quiet operation, safety, cost and maintainability |
| Humanoid | Torque density, mass, backdrivability, thermal performance and impact tolerance |
| Quadruped | Dynamic torque, bandwidth, shock loading and energy efficiency |
| Exoskeleton | Low mass, backdrivability, quiet operation and human-interface control |
| Soft robot | Compliance, deformation and application-specific force generation |
How Should a Robot Actuator Be Selected?
Selection should begin from the load case, motion profile and system interfaces—not from rated torque alone. The twelve dimensions below frame a system-level review.
1
Define the load case
- Payload, link mass, moment arm, gravity direction
- External forces, acceleration, impact and shock
- Friction and duty cycle
2
Define the motion profile
- Range of motion, maximum speed, acceleration
- Cycle frequency, holding periods, reversals
- Trajectory shape
3
Calculate output torque or force
- Static rotary estimate: Torque = Force × moment arm
- Rotary power = Torque × angular velocity
- Linear power = Force × linear velocity
4
Evaluate continuous and peak output
- Continuous and peak torque or force
- Peak duration, RMS load, holding load
- Regenerative load
5
Evaluate speed and transmission ratio
- Motor operating speed, output speed, gear ratio
- Transmission efficiency, input-speed limit
- Overspeed condition
6
Evaluate inertia
- Motor rotor, transmission and reflected load inertia
- Link and payload inertia
7
Evaluate stiffness and compliance
- Torsional and structural stiffness
- Transmission compliance and intentional elastic elements
- Deflection under load and control implications
8
Evaluate friction, backlash and backdrivability
- Static and dynamic friction, lost motion
- Gear backlash, seal friction, cogging
- Backdrive torque
9
Evaluate thermal performance
- Winding, drive and gearbox temperature
- Housing thermal path, ambient temperature, cooling
- Peak-to-continuous operating ratio
10
Evaluate feedback and control
- Motor and output encoders, torque and temperature sensors
- Control modes, bandwidth, communication protocol
- Diagnostics
11
Evaluate physical integration
- Envelope, mass, centre of gravity, mounting flange
- Output bearing, cable routing, connector orientation
- Sealing and service access
12
Evaluate lifecycle and sourcing
- Expected life, lubrication, bearing and gear wear
- Calibration, firmware support, repair model
- Spare parts, product lifecycle, alternative suppliers
Starting formulas:
Rotary: Torque = Force × Perpendicular moment arm
Rotary power: Power = Torque × Angular velocity
Linear power: Power = Force × Linear velocity
These formulas are starting points. A final actuator model must include acceleration, transmission efficiency, inertia, friction, shock, safety margin and the complete operating cycle.
Research on direct-drive and quasi-direct-drive systems treats torque density and actuator inertia as central design variables for dynamic robots. Proprioceptive actuator design (IEEE).
Why Is Rated Torque Alone Not Enough?
Rated torque is meaningful only together with speed, duration, duty cycle, temperature and cooling conditions. An actuator may deliver a high short-duration peak torque but be unable to sustain that output continuously without overheating.
Continuous operating region
Short-duration peak region
Thermal or speed limit
For repeating motion cycles, actuator heating is influenced by the complete torque-versus-time profile rather than only its maximum point. Do not apply one universal safety factor without analysing the duty cycle.
How Do Stiffness, Backlash, Compliance and Backdrivability Differ?
| Term | Meaning | Why it matters |
|---|---|---|
| Stiffness | Resistance to deformation under load | Position error, vibration and control performance |
| Backlash | Free movement caused by clearance | Direction-reversal accuracy |
| Lost motion | Total output displacement not reproduced immediately at input | Precision under reversal and load |
| Compliance | Deflection under force or torque | Interaction, shock tolerance and position accuracy |
| Backdrivability | Ease of moving the actuator from its output | Human interaction and force control |
| Friction | Resistance to relative movement | Efficiency, control sensitivity and heating |
| Damping | Energy dissipation during motion | Oscillation and transient response |
High stiffness and high backdrivability are not the same objective. An actuator may be mechanically stiff yet difficult to backdrive because of friction and transmission ratio.
What Interfaces Must Be Defined for a Robot Actuator?
| Interface | Required information |
|---|---|
| Mechanical input/output | Flange, pilot, shaft, bolt pattern and tolerances |
| Structural load | Radial, axial and overturning moment capacity |
| Electrical power | Voltage, continuous current, peak current and protection |
| Feedback | Encoder type, resolution, accuracy and signal format |
| Communication | EtherCAT, CAN, RS-485 or other protocol |
| Control | Position, velocity, torque and impedance modes |
| Safety | Brake, safe torque off, limits and fault behaviour |
| Software | SDK, API, configuration tool, firmware and licences |
| Thermal | Ambient limit, cooling method and mounting thermal path |
| Environmental | IP rating, vibration, contamination and corrosion |
| Lifecycle | Repair, spares, firmware and end-of-life policy |
What Sensors and Control Modes Does a Robot Actuator Need?
Feedback devices
- Motor encoder, output encoder, absolute position encoder
- Torque sensor, current sensing, temperature sensing
- Limit switches and brake-status sensing
Control modes
- Current or torque control, velocity control, position control
- Impedance control, force control, open-loop actuation
Dual-encoder architecture
A motor-side encoder measures motor or transmission-input motion. An output-side encoder measures the joint output and can expose transmission deflection, backlash or lost motion that a motor encoder alone cannot observe.
See the robot sensors guide for sensor parameters and the robot controllers guide for motion-control architecture.
How Should a Robot Actuator Be Tested?
Static performance
- Peak torque or force, holding torque
- Stiffness, backlash or lost motion
- Brake holding capacity and static efficiency
Dynamic performance
- Torque-speed envelope, acceleration response
- Control bandwidth, tracking error
- Backdrivability and transient response
Thermal performance
- Continuous-load temperature and peak-load recovery
- Housing and drive temperature
- Thermal derating and cooling dependence
Durability
- Duty-cycle endurance, gear and bearing wear
- Seal life, cable flex life, brake cycles
- Lubrication life
Environmental and integration performance
- Vibration, shock, ingress protection, temperature range
- Communication reliability, fault behaviour, EMC where applicable
remains current for system-level performance criteria and testing of manipulating industrial robots, but it should not be presented as a component-level actuator test standard.
Evidence rule: Every published performance value should identify test configuration, supply voltage or pressure, operating temperature, cooling conditions, duration, transmission ratio, measurement location and uncertainty or tolerance where relevant.
Common Mistakes When Selecting Robot Actuators
| Mistake | Consequence |
|---|---|
| Selecting from peak torque alone | Overheating during sustained operation |
| Ignoring speed at required torque | Actuator cannot follow the motion profile |
| Excluding link and payload inertia | Poor acceleration or unstable control |
| Assuming rated payload determines actuator torque | Incorrect joint-load estimate |
| Ignoring output-bearing loads | Premature bearing or housing failure |
| Comparing only gearbox backlash | Stiffness, friction and life mismatch |
| Treating a motor as a complete actuator | Missing transmission, feedback and structural requirements |
| Ignoring cable and connector routing | Flex-life or packaging failures |
| Ignoring firmware and protocol dependency | Integration delay or supplier lock-in |
| Accepting unqualified peak values | Non-comparable supplier claims |
| Selecting a prototype actuator without lifecycle review | Production or obsolescence risk |
| Assuming a module is maintenance-free | Unplanned replacement and downtime |
Integrated Robot Actuator Module or Discrete Components?
| Dimension | Integrated actuator module | Discrete joint design |
|---|---|---|
| Development speed | Faster | Slower |
| Packaging | Supplier-defined | Buyer-defined |
| Internal interfaces | Pre-integrated | Buyer must engineer |
| Optimisation | Limited to module options | Greater architecture control |
| Repair | Often module replacement | Component-level repair possible |
| Supplier dependency | Higher | Potentially lower |
| Software access | May be restricted | Buyer can select control architecture |
| Alternative sourcing | More difficult | Potentially easier |
| Validation burden | Lower initially | Higher |
| High-volume cost | Supplier-dependent | More optimisation potential |
Integrated actuator modules suit projects prioritising development speed, compact packaging and known interfaces. Discrete joint architectures suit projects requiring proprietary performance, cost optimisation, component-level service or alternative sourcing.
What Evidence Should a Robot Actuator Supplier Provide?
Product evidence
- Dimensioned drawings, torque-speed curves
- Continuous and peak-load definitions, thermal-test conditions
- Efficiency data, backlash and stiffness methods
- Load limits and communication documentation
Manufacturing evidence
- Motor winding process, gear or reducer source
- Bearing and encoder source, assembly controls
- Alignment, preload control, calibration
- End-of-line testing and traceability
Reliability evidence
- Life-test method and duty-cycle assumptions
- Failure modes and warranty-return data
- Brake and bearing life, gear wear
- Cable and connector testing
Software and lifecycle evidence
- Firmware ownership, configuration access, diagnostic tools
- Update policy, protocol documentation, SDK or API
- Warranty, repair process, spare-parts policy
- Backward compatibility and end-of-life notification
Verified through primary documentation
Supplier-reported
Supported by independent evidence
Not confirmed
Not disclosed
Sourcing Robot Actuators in China
China has broad manufacturing capability across motors, reducers, drives, machining, electronics and integrated robotic joints. The central sourcing question is not whether a supplier can assemble an actuator. It is which critical technologies it designs and controls, which components come from third parties, and whether it can demonstrate repeatable performance, calibration, thermal control and lifecycle support.
China’s actuator supply base includes integrated robot-joint manufacturers, servo-motor and drive suppliers, and precision-machining and electronics assembly firms. Critical dependencies often sit in reducers, encoders and torque sensors—some domestic, some imported. Buyers should verify owned versus outsourced assembly, calibration and end-of-line testing, firmware and communication ownership, customisation and tooling scope, engineering-change control, and overseas service and repair capability.
Supplier substitutions in motors, reducers or encoders can change reflected inertia, thermal behaviour and control tuning without visible mechanical change. Lifecycle and obsolescence commitments should be confirmed before production release, especially when firmware or protocol access is required for integration.
What Information Should Be Included in a Robot Actuator Requirement?
Robot and application context
- Robot category and joint location
- Application and development stage
- Operating environment and destination market
- Expected volume
Load and motion
- Continuous and peak torque or force
- Peak duration, maximum speed, acceleration
- Range of motion, duty cycle, holding requirement
- Shock loads
Mechanical
- Envelope, mass target, output flange, mounting
- Moment, radial and axial loads
- Stiffness, backlash or lost motion
- Brake requirement
Electrical, control and environment
- Supply voltage, continuous and peak current
- Control mode, feedback, communication protocol
- Control-cycle requirement and safety interfaces
- Ambient temperature, cooling, ingress protection
- Vibration, shock, noise, cleanroom or washdown
Lifecycle and validation
- Expected life, maintenance, calibration
- Required test evidence, sample quantity, reliability requirement
- Repair, spare parts and firmware support
Frequently Asked Questions
What is a robot actuator?
A robot actuator is the subsystem that converts an energy source and control command into controlled mechanical motion. It may include a motor or fluid-power element, drive, transmission, feedback, brake, bearings, housing and control electronics. See the definition section and the parent robot components guide for system context.
What does an actuator do in a robot?
An actuator produces the rotary or linear movement that allows a robot to position links, wheels or end effectors. It closes the loop between control commands and physical motion through feedback sensors. Without actuators, the controller, sensors and software cannot produce mechanical action. Joint-level architecture is covered in the robot arm actuators section.
What is the difference between a motor and an actuator?
A motor converts electrical energy into rotational motion. An actuator is the complete motion-producing assembly and may include the motor, reducer, encoder, brake, bearings, housing and drive electronics. Rated motor torque does not include transmission effects, bearing loads or thermal constraints. Read the comparison table and the servo motors guide for motor-level parameters.
What are the main types of robot actuators?
Actuators can be classified by energy source (electric, hydraulic, pneumatic), output motion (rotary, linear) and mechanical architecture (direct drive, geared, series elastic, quasi-direct drive and others). These dimensions overlap. The actuator types section explains each category without treating one taxonomy as universal.
What actuator is used in a robot arm?
Most articulated electric robot arms use rotary servo actuators at each joint, often combining a motor, drive, reducer, encoders, brake, bearings and housing. Joint priorities differ by location—shoulder joints need high torque and moment capacity, while wrist joints emphasise compact size. See the robot arm actuators table.
How does a robot joint actuator work?
A joint actuator receives a position, velocity or torque command from the controller, converts it through the drive into motor or fluid power, transmits motion through a reducer or direct coupling, and uses encoders or torque sensors to close the control loop. The operating principle section describes the full sequence.
What is an integrated robot actuator?
An integrated robot actuator or joint module packages motor, reducer, encoder, brake, bearings, housing and often drive electronics in one assembly. It can accelerate development but concentrates supplier dependency. Compare integrated and discrete approaches in the architecture comparison and component table.
What is a series-elastic actuator?
A series-elastic actuator places an elastic element in series between the drive and output, enabling force sensing, shock tolerance and compliant interaction at the cost of added deflection and control-bandwidth trade-offs. It is one mechanical architecture among several described in the architecture comparison.
What is a quasi-direct-drive actuator?
A quasi-direct-drive actuator combines a high-torque-density motor with a low-ratio transmission to improve backdrivability and dynamic control compared with conventional high-ratio geared joints. It trades larger motor size and thermal demand for lower reflected inertia. See the mechanical architectures section.
How do I calculate robot actuator torque?
Start with static estimates: Torque = Force × perpendicular moment arm. Include link mass, payload, gravity direction, acceleration, friction and safety margin. Rotary power equals torque times angular velocity. These are starting points—the selection framework requires the complete operating cycle, not peak load alone.
Why is continuous torque different from peak torque?
Peak torque describes short-duration output under defined conditions. Continuous torque describes what the actuator can sustain without exceeding thermal limits. An actuator may meet peak torque briefly but overheat during repetitive cycles. The torque-speed envelope section explains why rated torque must be read with speed, duty cycle and cooling.
What is actuator backdrivability?
Backdrivability is the ease of moving an actuator from its output side—important for force control, human interaction and impact tolerance. It depends on transmission ratio, friction and efficiency, not stiffness alone. An actuator can be stiff yet hard to backdrive. See the mechanical behaviour table.
Are hydraulic actuators better than electric actuators?
Neither is universally better. Electric actuators suit broad precision robotics with digital control. Hydraulic actuators can offer high force density for heavy-duty applications but require fluid infrastructure and maintenance. Pneumatic actuators suit compliant or simple mechanisms. Compare all three in the energy-source comparison.
What actuators are used in humanoid robots?
Humanoid robots often prioritise torque density, low mass, backdrivability, thermal performance and impact tolerance across many compact joints. Quasi-direct-drive, series-elastic and high-ratio geared electric actuators all appear depending on joint function. Humanoid requirements are one row in the robot-category table, not the defining scope of this guide.
How do I choose a robot actuator supplier?
Request dimensioned drawings, torque-speed curves with test conditions, manufacturing and calibration evidence, firmware access and lifecycle commitments. Verify which critical components the supplier designs versus sources. Use the supplier evidence framework and supplier qualification guide for structured review.
How do I source robot actuators from China?
Define the actuator requirement, interfaces and validation plan before supplier search. Verify owned technology, reducer and encoder dependencies, calibration, firmware access and change control. China offers broad manufacturing depth, but location does not establish suitability. See the China sourcing section and component sourcing service.
Need Help Sourcing Robot Actuators?
If you have defined the joint load case, motion profile and interface requirements, Yana can help structure supplier research, actuator comparison and validation planning for robotics components in China.