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

The electric motor is generally connected 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 variety of motor sizes might be mounted to those actuators depending on requirements.

Linear actuators have incorporated linear bearings that support the moving payload, as well as rotary bearings that help either the lead screw, ball screw or belt pulleys. This then permits them to operate as ‘stand-alone’ units, making them easy to mount into present machines and eliminating the necessity to design/manufacture very costly customized parts. To increase the load capacity and stability of a linear actuator system, they are often paired up with the payload carried between them, equivalent to in an XY gantry fashion stage. In this case, a shaft or belt is usually used to keep the 2 actuators in sync with each other.

Features of Linear Actuators

Linear Actuators have the next features:

High repeatability

Positioning accuracy

Easy 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

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 utilized in industries including:

Packaging

Meals processing

Industrial vehicles

Factory automation

Materials dealing with

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 can help you achieve one of the best results. Lead Screw Actuators, Ball Screw Actuators and Belt Actuators are three types of linear actuators that can be utilized in numerous 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 the most commonly used methods to produce the rotary motion, as they’re generally used in low cost 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 embody agricultural equipment and manual 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 principle this is very 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 very environment friendly method of changing rotary motion to linear motion. Stepper or servo motors are generally used to provide the rotary motion. Ball screw actuators are well suited to repeatable indexing and quick cyclic applications reminiscent of machine tools, scientific instruments 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 paired utilizing a flexible coupling. They offer a comparatively low-value alternative, as they inherently have a decrease level of precision. Belt pushed linear actuators are superb for lengthy travel and high linear pace applications such as packaging and automatic materials handling systems.