Electric Linear Actuators
Electric motors drive screws, belts, gears, or other mechanisms to create controlled linear displacement. They are common in automation and positioning systems.
MOTR / ACT — LINEAR MOTION REFERENCE
Linear Actuators.
Linear actuators convert electrical, pneumatic, hydraulic, mechanical, or other forms of input energy into controlled straight-line movement. They are used to push, pull, lift, clamp, position, open, close, adjust, and transport loads throughout industrial machinery and automation systems. Selection depends on required force, stroke, speed, duty cycle, positioning accuracy, power source, mounting geometry, environmental protection, control method, load direction, maintenance, and expected service life.
OPERATING PRINCIPLE
Actuation creates useful straight-line work.
A linear actuator takes energy from a power source and converts it into movement along a defined axis. In an electric actuator, a motor may rotate a screw or another transmission component. In a pneumatic or hydraulic actuator, pressure acts on a piston to create extension or retraction.
The actuator may provide its own internal guidance or operate alongside separate linear bearings that support external loads and control the path of motion.
Proper selection therefore requires distinguishing between the force required to move the load and the external forces or moments that should be carried by the machine structure.
BASIC ACTUATOR IDENTIFICATION
Stroke
Maximum usable linear travel between retracted and extended positions.
Force
Push or pull load capability under specified operating conditions.
Speed
Rate of extension, retraction, or commanded travel.
Duty
Permitted operating time and cycling pattern relative to rest.
Power
Electrical, pneumatic, hydraulic, mechanical, or specialized input.
Control
Limit, position, speed, force, or programmable motion control.
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Common Linear Actuator Types
Actuator families differ in their energy source, transmission method, available force, speed, controllability, accuracy, packaging, and maintenance.
Electric Cylinders
Electromechanical actuators packaged in a cylinder-like format that combine an electric motor and mechanical transmission for controlled push-pull motion.
Ball Screw Actuators
Motor-driven ball screw systems use rolling elements between the screw and nut to produce efficient and comparatively precise linear motion.
Lead Screw Actuators
Rotary motion is converted to linear travel through sliding engagement between a threaded screw and nut.
Stepper Motor Actuators
Stepper motors drive a linear transmission so movement can be commanded in controlled increments for positioning, indexing, or automated adjustment.
Pneumatic Actuators
Compressed air acts on a piston or other pressure-responsive element to create extension and retraction.
Hydraulic Actuators
Pressurized hydraulic fluid creates linear force through a piston-and-cylinder arrangement suited to demanding high-force applications.
Telescoping Actuators
Multiple nested sections extend to provide substantial travel while retaining a comparatively short retracted length.
Miniature Actuators
Compact actuators designed for short strokes, smaller loads, limited installation spaces, instrumentation, optics, electronics, and compact automation.
DRIVE / CONVERSION
The drive mechanism determines how input becomes travel.
Different actuator mechanisms trade speed, force, precision, efficiency, stiffness, stroke length, maintenance, and packaging against one another.
ACTUATOR DRIVE METHODS
Ball Screw
Rotating screw and recirculating ball nut convert rotary
input to efficient linear travel with low sliding friction.
Lead Screw
Threaded screw and sliding nut provide a compact
rotary-to-linear conversion mechanism.
Belt Drive
Belt-and-pulley systems can provide long travel
and comparatively high linear speeds.
Rack + Pinion
Rotating pinion engages a linear rack to create
straight-line travel over potentially long distances.
Pneumatic Piston
Compressed air pressure acting across a piston area
produces linear force and displacement.
Hydraulic Piston
Pressurized liquid acts on a piston to generate
high linear forces in a compact cylinder.
Linear Motor
Electromagnetic force is generated directly along
the axis of travel without a conventional screw conversion.
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Force, Stroke, Speed & Duty
These four requirements define much of the basic actuator envelope and should be established before comparing technologies.
Force
Determine the force required to start, accelerate, move, hold, lift, clamp, or overcome process resistance throughout the entire travel.
Stroke
Stroke is the required working travel. Installation planning should also consider retracted length, extended length, and end clearances.
Speed
Required extension and retraction speed affects motor sizing, gearing, screw lead, fluid flow, cycle time, and overall actuator technology.
Duty Cycle
Frequent cycling or prolonged operation increases thermal, lubrication, wear, sealing, and power demands.
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Linear Actuator Specifications
Replacement compatibility requires checking performance, dimensions, power, controls, and mounting rather than comparing stroke length alone.
Specification
What to Verify
Why It Matters
Stroke
Required usable extension and retraction distance.
Determines whether the mechanism reaches every required position.
Force
Dynamic, static, push, pull, holding, or applicable force rating.
Actuator must move and support the real application load.
Speed
Extension, retraction, and motion-profile requirements.
Determines cycle time and influences available force.
Duty Cycle
Cycles per period, run time, rest time, and expected service.
Prevents thermal overload and premature wear.
Power Source
Voltage, current, compressed air, hydraulic pressure, or other supply.
Must correspond with the available machine infrastructure.
Positioning
End-to-end travel, intermediate positioning, repeatability, and accuracy.
Determines required feedback, motor, drive, valve, or control strategy.
Mounting
Clevis, trunnion, flange, foot, face, side, or custom mounting.
Determines physical compatibility and load alignment.
Environment
Dust, water, washdown, chemicals, temperature, outdoor or clean conditions.
Influences sealing, materials, lubrication, connectors, and protection.
Feedback
Limit switches, potentiometer, encoder, sensor, or other position feedback.
Must integrate correctly with machine controls.
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Linear Actuator Selection
Define the mechanical work first, then choose the actuator technology and control architecture that can perform it reliably.
01
Define the Movement
Establish required travel, direction, speed,
acceleration, stopping points, positioning accuracy,
cycle rate, and motion sequence.
02
Calculate the Force
Include load weight, friction, process resistance,
gravity, acceleration, external forces, safety margin,
and forces that vary across the stroke.
03
Choose the Power Source
Compare electrical, pneumatic, and hydraulic infrastructure,
efficiency, available pressure or voltage, maintenance,
control requirements, and installation cost.
04
Match the Mechanics
Verify retracted length, extended length, mounting points,
available envelope, rod orientation, side-load limits,
guiding, alignment, and surrounding machine geometry.
05
Define the Controls
Determine whether the actuator needs simple extend-retract
control, intermediate positioning, programmable motion,
speed control, force control, synchronization, or feedback.
06
Validate the Duty
Confirm thermal limits, cycle life, seals, lubrication,
environmental exposure, maintenance access, load direction,
stopping behavior, and actual machine operating conditions.
Compatibility / Note 09
Equal stroke and force do not guarantee interchangeability.
Two actuators can share similar force and stroke ratings while differing in retracted length, speed, duty cycle, mounting centers, side-load capability, voltage, current, pressure, feedback, limit switches, connector pinout, control logic, environmental rating, and end-of-travel behavior. Replacement decisions should verify the entire mechanical and control interface. Use the Motor & Drive Selection Guide and Component Compatibility Guide when evaluating substitutions.
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Linear Actuator Resources
Additional references for electric cylinders, 12-volt actuators, miniature actuators, pneumatic actuation, and related linear-motion components.
12 Volt Linear Actuators
Focused resource covering low-voltage electric linear actuators used in automation, vehicles, machinery, positioning, and related applications.
Research 12V ActuatorsElectric Cylinders
Industry resource for electric cylinder and electromechanical linear actuator systems used in automated positioning and industrial machinery.
Research Electric CylindersMiniature Linear Actuators
Supporting reference for compact linear actuators used where installation space, travel, and component size are tightly constrained.
Research Miniature ActuatorsPneumatic Actuators
Related resource covering compressed-air actuators, cylinder-driven motion, applications, configurations, and industrial sourcing.
Research Pneumatic ActuatorsServo & Stepper Motors
OpenType reference for precision motor systems used to drive controlled positioning, indexing, and screw-based linear mechanisms.
Precision Motor ReferenceLinear Bearings
Review the bearing and guide components used to support external loads and constrain straight-line actuator movement.
Linear Bearing Reference
Reference note:
External resources are provided for additional research and
do not establish product compatibility, interchangeability,
certification, approval, or endorsement. Verify force, stroke,
speed, duty cycle, power source, mounting, side-load capability,
feedback, controls, environmental protection, and service
requirements before specifying or replacing a linear actuator.
RELATED / MOTION
Continue the Motor & Drive Reference
Compare linear actuators with electric motors, precision motion systems, gearing, and linear bearing components.