Types of Linear Actuators

Types of Linear Actuators

There are three main types of linear actuators that can be used in various applications to produce motion. They are Lead Screw Actuators, Ball Screw Actuators and Rodless Actuators.

The primary purpose of a linear actuator is to make an object move forward/reverse by conventionally converting rotary motion into linear motion. Whist all linear actuators technically do the same job, you can get the best results by picking the correct type of linear actuator for your system. 

Lead Screw Actuators

A Lead Screw Actuator uses a mechanical screw to translate the rotary motion from a handwheel/motor to linear motion. A manually driven screw or an AC induction motor are the most commonly used. A lead screw itself is fairly low inefficiency due to the design of the thread profile.

Lead screw actuators typically suit low-cost applications with high loads and slow speeds, where the fail-safe inefficiency reduces the risk of back driving (and load dropping for vertical applications) under power failure.  Applications include agricultural equipment and manual lift systems where safety is critical.

Ball Screw Actuator

A Ball Screw Actuator uses a rolled or ground mechanical screw with a recirculating ball bearing nut assembly for higher precision and efficiency, which translates rotary motion into linear motion with increased force, higher accuracy and lower friction. Stepper and Servo motors are commonly used for higher accuracy/speeds and finer positioning.  

Sizing the motor is dependent upon acceleration, as well as no-load forces, maximum linear speed and loads. Typically repeatable indexing systems would use a stepper motor, whereas a fast cyclic application would use a servo motor solution. Applications include packaging, machine tools and electronics assembly.

Want to know how to adapt a Ballscrew to a level which will make it environmentally and eco-friendly? Have a read of our blog post to find out more.

Rodless Actuator

A Rodless Actuator can use either a lead or ballscrew, but is designed to the deliver thrust and carry loads without the need for external guides. They are self-supporting and require minimal engineering to incorporate within a machine design. A rodless actuator can be utilised for low to medium accuracy applications for either lighter, repetitive movements or heavier loads requiring softer movements.

One example is the LoadMaster 80 rodless actuator from Thomson Linear; it is uniquely designed for quiet and smooth operation, making it highly suitable for indoor domestic and medical environments. These actuators incorporate a DC motor and gearbox assembly. Movement to the carriage is provided using either a ball or lead screw drive.

Features of Linear Actuators

Linear actuators can offer advantages over mechanical and hydraulic systems in many applications. They are self-contained, rugged and durable, making them ideal anywhere you want to lift, lower, push, pull, manipulate or position a load. Many of our Linear Actuators have the following features:

• High repeatability
• Positioning accuracy
• Smooth operation
• Long life
• Easy maintenance or maintenance-free
• Protection ratings available for some models
• Suitable for harsh environments
• Compact design
• Rugged and reliable
• Safe operation
• Versatile

Linear Actuators are well used in industries including:

• Packaging
• Food processing
• Industrial vehicles
• Factory automation
• Material handling
• Clean energy
• Printing
• Automotive
• Machine tool
• Marine
• Aerospace
• Defence
• Pharmaceutical industries