An electric linear actuator converts electrical energy into precise straight-line motion. It's the technology behind adjustable  hospital beds, standing desks, solar tracking systems, and thousands of industrial applications. This guide explains  everything you need to know — from basic principles to specification and selection.

What Is an Electric Linear Actuator?

An electric linear actuator is a device that produces linear (straight-line) motion from electrical energy. Unlike a rotary motor — which spins a shaft — a linear actuator extends and retracts a rod in a straight line, generating push or pull force.

The motion is controlled electrically: apply voltage to extend, reverse polarity to retract, remove power to stop (and hold position).

Core applications include:

• Adjustable medical beds and chairs
• Height-adjustable furniture (standing desks, recliners, sofas)
• Solar panel trackers
• Agricultural automation (seeders, boom sprayers, gates)
• Industrial machinery and conveyor systems
• Marine and offshore equipment

Electric linear actuators have largely replaced hydraulic and pneumatic cylinders in many applications because they require no fluid systems, no compressors, generate cleaner and quieter operation, and offer precise position control with simple electrical integration.

How Does an Electric Linear Actuator Work?

Most electric linear actuators share the same basic operating principle:

DC Motor → Gearbox → Lead Screw → Nut → Output Rod

1.DC Motor — converts electrical energy into rotary motion. Typically a permanent-magnet brush DC motor (12V or 24V in most applications).

2.Gearbox — reduces motor speed and multiplies torque. The gear ratio determines the actuator's output speed and force characteristics.

3.Lead Screw — a precision screw shaft that converts rotary motion (from the gearbox) into linear motion. The lead (thread pitch) determines how far the rod moves per motor revolution.

4.Drive Nut — a nut threaded onto the lead screw. As the screw rotates, the nut (and attached output rod) translates linearly.

5.Output Rod — the extending/retracting shaft that delivers force to the load.

Self-locking: Trapezoidal lead screws used in most actuators are inherently self-locking — the mechanical geometry prevents the screw from being back-driven by an external load. This means the actuator holds its position without  power, an essential feature for safety-critical applications like hospital beds and stairlifts.

Limit switches: Built-in limit switches at both ends of the stroke automatically cut motor power when the rod reaches full extension or full retraction. This prevents mechanical damage — you cannot "over-travel" the actuator by holding a switch past the end of stroke.

Types of Electric Linear Actuators

1.Standard (Rod) Actuator

The most common type. A rod extends from one end of the body, providing push/pull force. Available in a wide range of forces (50N to 10,000N+) and strokes (50mm to 1,000mm+).

Applications: Furniture, agricultural gates, industrial automation, recreational vehicles

JDR Series: Standard Actuator Series (FY011, FY014)

2.Mini Actuator

Compact, lightweight, lower force. Ideal for space-constrained applications and lighter loads.

Applications: Medical chairs, dental equipment, small automation, embedded systems

JDR Series: Mini Actuator Series (FY017, FY019, FY022)

3.Industrial (Heavy-Duty) Actuator

Reinforced housing, higher force ratings, higher IP protection, extended temperature range. Designed for permanent outdoor or demanding industrial use.

Applications: Solar trackers, agricultural machinery, marine, mining, heavy industrial

JDR Series: Industrial Actuator Series (FY015, FY021)

4. Medical Actuator

Purpose-designed for patient-care equipment. Quiet operation, self-locking, higher safety factors, specific certifications (CE, IEC 60601).

Applications: Hospital beds, bariatric beds, blood donation chairs, dialysis chairs

JDR Series: Medical Actuator Series (FY030, FY031, FY032, FY011C)

5.Lifting Column

A telescoping multi-stage actuator that provides vertical lifting with a compact retracted height. Used for height-adjustable furniture and equipment.

Applications: Standing desks, sit-stand workstations, reception counters, height-adjustable examination tables

JDR Series: Lifting Column Series (FY018)

Key Specifications Explained

Force (Load Capacity)

Force is the amount of push or pull the actuator can generate, measured in Newtons (N) or pounds-force (lbs).

Two force ratings are specified:

• Dynamic force — force while moving (used to select the actuator for your load)
• Static force — holding force when stopped (usually higher)

How to determine required force: Use our Engineering Force Calculator. For basic applications, the required force equals the load weight multiplied by the mechanical advantage of your linkage geometry, plus a safety factor of 1.5–2×.

Stroke Length

How far the rod extends from its fully retracted position. Ranges from 50mm to 1,000mm+ depending on the model.

Select stroke length based on the required range of motion in your application. Allow a few mm of margin at both ends —do not design a mechanism that requires operation right at the physical limit.

Speed

Measured in mm/s at rated load. Speed and force are inversely related (for the same motor): higher force = lower speed; lower force = higher speed.

• Furniture and medical applications: 5–15 mm/s (smooth, controlled movement)
• Industrial/automation: 10–30 mm/s (faster throughput)
• Solar trackers: 2–8 mm/s (slow incremental adjustment)

Voltage

Most DC linear actuators operate at 12V DC or 24V DC. Industrial versions may also support 36V, 48V, or 72V DC.

• 12V: Common in battery-powered and automotive applications, small residential systems
• 24V: Standard for medical equipment, commercial furniture, most industrial control systems
• 48V+: Battery storage integration, utility-scale solar, high-power industrial

JDR actuators are available in 12V, 24V, and 48–72V DC configurations.

IP Rating (Ingress Protection)

Defines protection against dust and water. Specified per IEC 60529:

For all permanently outdoor applications, specify IP66 as the minimum. See our complete IP rating guide for details.

Duty Cycle

The percentage of time the actuator can be operated within a given period. Standard actuators are typically rated at 10%  duty cycle — run for 10 seconds, rest for 90 seconds.

Exceeding the duty cycle causes overheating and motor damage. For high-frequency applications, specify industrial-grade actuators with higher duty cycle ratings. See our duty cycle guide for calculation methods.

Feedback Options

For position-controlled applications, actuators can include:

• Hall Effect Sensor (pulse output) — high-precision position feedback, compatible with most PLC and microcontroller systems
• Potentiometer (analog output) — simple analog voltage proportional to position
• Reed Switch — simple pulse feedback for less demanding applications

Feedback is essential for solar trackers, synchronized multi-actuator systems, and any application requiring specific position stops.

Electric vs. Hydraulic vs. Pneumatic: When to Choose Electric

Choose electric linear actuators when:

• Precise position control is required
• Clean/medical/food environments
• Low maintenance is a priority
• Battery or solar-powered systems
• Integration with electronic control systems

Consider hydraulics when:

• Forces exceed 50,000N
• Extreme shock loading is expected
• Existing hydraulic system infrastructure is in place

5 Key Steps to Select the Right Electric Linear Actuator

Step 1: Determine Required Force

Calculate the force your actuator needs to generate at the output attachment point, accounting for the mechanical advantage of your linkage. Use JDR's Force Calculator. Apply a 1.5–2× safety factor.

Step 2: Determine Required Stroke

Measure the linear distance the attachment point must travel through the full range of your application's motion. Allow 5– 10mm margin.

Step 3: Select IP Rating for Your Environment

Indoor and dry → IP44/IP54

Sheltered outdoor or dusty indoor → IP65

Outdoor (permanent) → IP66 minimum

Coastal/flood risk → IP67

Step 4: Define Duty Cycle Requirements

Calculate your application's on-time and total cycle time. Select an actuator rated at least 50% higher than your calculated duty cycle (see duty cycle guide).

Step 5: Specify Feedback Requirements

No feedback needed → standard actuator

Position control or synchronization → Hall effect feedback option

Analog position signal → potentiometer option

Application Guide: Which JDR Series to Choose

Frequently Asked Questions

Q: What is the difference between a linear actuator and a linear motor?

A: A conventional electric linear actuator uses a rotary motor driving a lead screw to produce linear motion. A linear motor directly generates linear motion electromagnetically, without a rotating component. Linear motors are faster and have no mechanical wear in the drive mechanism, but are much more expensive and less common in standard industrial applications.

Q: Can a linear actuator be used horizontally?

A: Yes. Linear actuators work equally well in any orientation — vertical, horizontal, or angled. The force requirement changes with orientation (horizontal loads don't need to overcome gravity), but the actuator mechanics are unaffected by mounting angle.

Q: How do I control the speed of a linear actuator?

A: Speed is controlled by varying the supply voltage using a PWM (Pulse Width Modulation) motor controller. Reducing PWM duty cycle reduces effective voltage and therefore speed. Some actuators have fixed-speed gearboxes; for variable speed, confirm the model supports PWM control. See our wiring guide for implementation details.

Q: Do I need a special controller for synchronized dual-actuator setups?

A: Yes, for precision synchronization. A simple parallel wiring connection will run two actuators simultaneously but does not correct for speed differences between units. For tight synchronization (e.g., <2mm difference across a solar tracker row), use a closed-loop controller with Hall effect feedback from both actuators.

Q: What certifications should a medical-grade linear actuator have?

A: At minimum: CE marking. For European medical devices, CE marking per the Medical Device Regulation (MDR) is required. For North America, UL/ETL listing is required for hospital-grade equipment. JDR medical actuators carry CE certification and are designed to be compatible with IEC 60601-1 requirements. Read our medical actuator guide for full certification details.

Summary

Electric linear actuators are versatile, precise, and low-maintenance solutions for generating controlled straight-line motion. Key selection parameters:

Force — calculate with safety factor, verify against dynamic and static ratings

Stroke — match to application range of motion with margin

IP rating — IP66 for all outdoor applications

Duty cycle — calculate and specify with 50% safety margin

Feedback — add Hall effect sensors for position-controlled applications

Voltage — 24V DC is the most common for commercial/industrial applications

JDR manufactures electric linear actuators across five series — Standard, Mini, Medical, Industrial, and Lifting Column — covering forces from 50N to 11,000N and strokes from 50mm to 750mm+. All products carry CE certification.

Browse the full JDR product range: Standard | Mini | Medical | Industrial | Lifting Column. Use our Engineering Force  Calculator or contact us for application engineering support.