A linear actuator is a mechanical device that combines a linear guide, drive mechanism, carriage-guidance system, and power source to produce controlled straight-line motion for moving or positioning a load. The drive mechanism—such as a ball screw, lead screw, belt, or fluid-powered piston—creates linear force, while the guidance system supports the carriage, controls its path, and resists side, moment, and cantilevered loads. Linear actuators are commonly classified as electric, mechanical, pneumatic, or hydraulic; electric and mechanical designs are often selected for controlled positioning, repeatability, clean operation, and integration with automated machinery.
PBC Linear designs guided belt-driven and screw-driven actuators powered by NEMA motors or hand cranks. Belt-driven actuators support long strokes and high speeds with low maintenance. Ball screw actuators provide high efficiency, load capacity, and positioning accuracy, while lead screw actuators offer quieter, more cost-effective motion with anti-backlash options for improved repeatability. Screw-driven configurations include external-nut actuators, where the screw rotates and a restrained nut travels along it; captive actuators, where the nut rotates and pushes a non-rotating screw in and out; and non-captive actuators, where the rotating nut travels along a screw that passes through the motor. Available configurations include multiple screw diameters, lead sizes, NEMA frame sizes, motor lengths, and actuator lengths to match specific force, speed, and travel requirements.
Carriage guidance is provided by either self-lubricating Gliding Surface Technology for low-maintenance operation in environments with dirt, heat, or vibration, or ball-bearing profile rails for greater moment capacity and cantilevered loads.
- Guided belt-driven, ball screw, and lead screw actuator options
- External-nut, captive, and non-captive screw configurations
- NEMA motor-driven and hand-crank models
- Multiple screw diameters, leads, motor lengths, and frame sizes
- Choose Self-lubricating Gliding Surface Technology for dirt, heat, and vibration or ball-bearing profile rail guidance for higher moment and cantilevered loads
- Load capacities up to 83,400N (18,750lb)
- Stroke lengths up to 6,000mm (236in)
- Miniature through heavy-duty actuator systems
Frequently Asked Questions
What is a linear actuator?
A linear actuator is a device that produces controlled straight-line motion by converting rotational or input force into linear movement. It is commonly used in automation, machinery, and positioning systems to move or position loads.
How does a linear actuator work?
A linear actuator works by converting motion from a motor, screw, or belt drive into linear movement. As the drive mechanism rotates or moves, it advances a carriage or rod along a guided path to produce controlled motion.
What are the main types of linear actuators?
The main types of linear actuators are electric, mechanical, pneumatic, and hydraulic. Electric and mechanical actuators are often preferred for their precision, cleanliness, and ease of integration, while pneumatic and hydraulic actuators are typically used for higher force applications.
What is the difference between a lead screw and a ball screw actuator?
Lead screw actuators use sliding contact between the screw and nut, making them quieter and more cost-effective, while ball screw actuators use rolling elements to reduce friction, providing higher efficiency, accuracy, and load capacity.
What is the difference between belt-driven and screw-driven actuators?
Belt-driven actuators are designed for long travel distances and higher speeds with lower cost and maintenance, while screw-driven actuators provide greater accuracy, stiffness, and load capacity for precise positioning applications.
When should a linear actuator be used instead of a cylinder?
Linear actuators are preferred when precise positioning, repeatability, and controlled motion are required, while pneumatic or hydraulic cylinders are typically used for simple extension and retraction with higher force but less control.
Do linear actuators require maintenance?
Maintenance depends on the design. Screw-driven actuators may require periodic lubrication, while some systems use self-lubricating materials or low-maintenance designs to reduce service requirements.
What factors should be considered when selecting a linear actuator?
Key factors include load capacity, speed, stroke length, required precision, environmental conditions, mounting configuration, and the type of drive mechanism used.
What provides guidance in a linear actuator?
Guidance in a linear actuator is provided by linear bearings or guide systems that support the carriage and maintain alignment. These may include sliding-contact guides for low maintenance or rolling-element guides for higher load and rigidity.
What are linear actuators used for?
Linear actuators are used in applications such as automation, material handling, packaging equipment, medical devices, and positioning systems where controlled linear motion is required.
