How does a Linear Actuator work?

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 into a system is for the need to move a payload in a linear fashion somewhat than a rotary one. As most conventional electrical motors are rotary, a linear actuator is used to convert rotary motion to linear motion.

The electrical 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. Quite a lot of motor sizes will be mounted to those actuators relying on requirements.

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

Options of Linear Actuators

Linear Actuators have the following options:

High repeatability

Positioning accuracy

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

Packaging

Food processing

Industrial vehicles

Factory automation

Material handling

Clean energy

Printing

Automotive

Machine tool

Marine

Aerospace

Defence

Pharmaceutical

Types of Linear Actuators

Picking the right type of linear actuator on your motion application can assist 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 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 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 because of 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 manual lift systems, the place 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 precept this is similar to a regular 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 environment friendly methodology of converting 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 comparable to 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 driven by a motor which is generally mounted perpendicular to the actuator and coupled using a flexible coupling. They provide a relatively low-price different, as they inherently have a lower level of precision. Belt driven linear actuators are excellent for lengthy journey and high linear speed applications resembling packaging and automatic materials handling systems.