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 primary reason for designing a linear actuator right into a system is for the necessity to move a payload in a linear fashion fairly than a rotary one. As most typical electric motors are rotary, a linear actuator is used to transform rotary motion to linear motion.

The electrical motor is generally connected 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 could be mounted to these actuators depending on requirements.

Linear actuators have incorporated linear bearings that assist the moving payload, as well as rotary bearings that assist either the lead screw, ball screw or belt pulleys. This then permits them to operate as ‘stand-alone’ gadgets, making them easy to mount into present machines and eliminating the necessity to design/manufacture very pricey customized parts. To extend the load capacity and stability of a linear actuator system, they can be paired up with the payload carried between them, reminiscent of in an XY gantry type stage. In this case, a shaft or belt is commonly used to keep the 2 actuators in sync with every other.

Features of Linear Actuators

Linear Actuators have the following options:

High repeatability

Positioning accuracy

Easy operation

Lengthy life

Easy upkeep or upkeep 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 used in varied applications that require a load to either be lifted, lowered, pushed, pulled, rotated or positioned. Linear Actuators are utilized in industries together with:

Packaging

Meals processing

Industrial vehicles

Factory automation

Materials dealing with

Clean energy

Printing

Automotive

Machine software

Marine

Aerospace

Defence

Pharmaceutical

Types of Linear Actuators

Picking the proper type of linear actuator in your motion application may also 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 various 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 driven screw or an AC induction motor are probably the most commonly used methods to supply 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 might 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 makes use of a high precision nut with recirculating ball bearings that rotate around a ground screw thread. In precept this is similar to a typical 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 method of changing rotary motion to linear motion. Stepper or servo motors are generally used to produce 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 pulleys and connected 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 matched using a flexible coupling. They provide a comparatively low-value alternative, as they inherently have a lower level of precision. Belt pushed linear actuators are very good for long travel and high linear speed applications reminiscent of packaging and automated material dealing with systems.