How does a Linear Actuator work?

Linear actuators work by moving an object or piece of equipment in a straight line, moving an object extremely accurately and repeatably if required. The first reason for designing a linear actuator into a system is for the need to move a payload in a linear fashion relatively 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 related to the linear actuator by a flexible coupling or a belt, enabling the motor to be mounted either axially or perpendicular to the linear actuator. A variety of motor sizes may be mounted to these actuators depending on requirements.

Linear actuators have incorporated linear bearings that support the moving payload, as well as rotary bearings that support either the lead screw, ball screw or belt pulleys. This then allows them to operate as ‘stand-alone’ gadgets, making them simple to mount into existing machines and eliminating the need to design/manufacture very pricey custom parts. To increase the load capacity and stability of a linear actuator system, they can be paired up with the payload carried between them, corresponding to in an XY gantry fashion stage. In this case, a shaft or belt is commonly used to keep the 2 actuators in sync with each other.

Features of Linear Actuators

Linear Actuators have the next options:

High repeatability

Positioning accuracy

Easy operation

Lengthy life

Easy maintenance or maintenance free

Protection rankings 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 various applications that require a load to either be lifted, lowered, pushed, pulled, rotated or positioned. Linear Actuators are used in industries together with:

Packaging

Meals processing

Industrial vehicles

Factory automation

Materials handling

Clean energy

Printing

Automotive

Machine tool

Marine

Aerospace

Defence

Pharmaceutical

Types of Linear Actuators

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

A Lead Screw Actuator makes use of 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 essentially the most commonly used methods to provide the rotary motion, as they are 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 will be an advantage as it helps to keep the payload stationary whilst not in motion. Applications embrace agricultural equipment and handbook lift systems, where safety and reliability are more critical than precision and performance.

A Ball Screw Actuator uses a high precision nut with recirculating ball bearings that rotate around a ground screw thread. In principle this is similar to an ordinary 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 very 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 quick cyclic applications such as machine tools, scientific devices and medical systems.

Belt actuators work the place a belt is carried between pulleys and connected to the moving carriage, then as the belt rotates the carriage is pulled along the actuator. One of many pulleys is driven by a motor which is generally mounted perpendicular to the actuator and coupled utilizing a versatile coupling. They offer a relatively low-cost different, as they inherently have a lower degree of precision. Belt driven linear actuators are excellent for lengthy travel and high linear pace applications equivalent to packaging and automatic material dealing with systems.