How does a Linear Actuator work?

Linear actuators work by moving an object or piece of equipment in a straight line, moving an object extraordinarily accurately and repeatably if required. The first reason for designing a linear actuator into a system is for the necessity to move a payload in a linear fashion slightly than a rotary one. As most typical electric motors are rotary, a linear actuator is used to transform rotary motion to linear motion.

The electric motor is generally linked to the linear actuator by a versatile coupling or a belt, enabling the motor to be mounted either axially or perpendicular to the linear actuator. A wide range of motor sizes will be mounted to these actuators depending on requirements.

Linear actuators have incorporated linear bearings that help the moving payload, as well as rotary bearings that support either the lead screw, ball screw or belt pulleys. This then permits them to operate as ‘stand-alone’ units, making them simple to mount into present machines and eliminating the need to design/manufacture very costly custom parts. To extend the load capacity and stability of a linear actuator system, they can be paired up with the payload carried between them, equivalent to in an XY gantry model stage. In this case, a shaft or belt is often used to keep the two actuators in sync with every other.

Features of Linear Actuators

Linear Actuators have the next options:

High repeatability

Positioning accuracy

Easy operation

Lengthy life

Easy upkeep or upkeep free

Protection scores available for some models

Suitable for harsh environments

Compact design

Rugged and reliable

Safe operation

Versatile

Industries and applications for Linear Actuators

Linear Actuators can be utilized in numerous applications that require a load to either be lifted, lowered, pushed, pulled, rotated or positioned. Linear Actuators are used in industries including:

Packaging

Meals processing

Industrial vehicles

Factory automation

Materials handling

Clean energy

Printing

Automotive

Machine instrument

Marine

Aerospace

Defence

Pharmaceutical

Types of Linear Actuators

Picking the correct type of linear actuator on your motion application will help you achieve the perfect results. Lead Screw Actuators, Ball Screw Actuators and Belt Actuators are three types of linear actuators that can be used in numerous applications to produce motion.

A Lead Screw Actuator uses a plain screw/nut arrangement to translate the rotary motion from a motor to linear motion. A manually pushed screw or an AC induction motor are the most commonly used methods to provide the rotary motion, as they’re generally used in low price and low precision applications. The ability of the actuator to ‘back drive’ is reduced over ball screw actuators due to the low effectivity of the screw/nut. In some applications, this could be an advantage as it helps to keep the payload stationary whilst not in motion. Applications include agricultural equipment and handbook lift systems, where safety and reliability are more critical than precision and performance.

A Ball Screw Actuator makes use of a high precision nut with recirculating ball bearings that rotate round a ground screw thread. In precept this is similar to a standard ball race with the load being transmitted by the rolling balls. The significant advantages of this system are high-precision and low friction, giving a really efficient technique of changing rotary motion to linear motion. Stepper or servo motors are generally used to supply the rotary motion. Ball screw actuators are well suited to repeatable indexing and fast cyclic applications such as machine tools, scientific devices and medical systems.

Belt actuators work where a belt is carried between two pulleys and hooked up to the moving carriage, then because the belt rotates the carriage is pulled alongside the actuator. One of many pulleys is pushed by a motor which is generally mounted perpendicular to the actuator and coupled utilizing a flexible coupling. They provide a comparatively low-cost different, as they inherently have a decrease level of precision. Belt pushed linear actuators are excellent for lengthy travel and high linear velocity applications such as packaging and automated materials dealing with systems.