Technical Blog

How does a Linear Actuator work?

Knowing the ins and outs of how a linear actuator works can help you make an educated decision when selecting the right one for your application. How do they work? What features do they have? What benefits will they add to your application? Find out more in our guide below to help you decide.

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 rather than a rotary one. As most conventional 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 flexible coupling or a belt, enabling the motor to be mounted either axially or perpendicular to the linear actuator. A variety of motor sizes can 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’ devices, making them easy to mount into existing machines and eliminating the need to design/manufacture very costly 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, such as in an XY gantry style stage. In this case, a shaft or belt is often used to keep the two actuators in sync with each other.

Features of Linear Actuators

Linear Actuators have the following features:

  • High repeatability
  • Positioning accuracy
  • Smooth 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 used in various 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 correct type of linear actuator for your motion application can help you achieve the best 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 the most commonly used methods to supply the rotary motion, as they are 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 efficiency of the screw/nut. In some applications, this can be an advantage as it helps to keep the payload stationary whilst not in motion. Applications include agricultural equipment and manual lift systems, where safety and reliability are more critical than precision and performance.
     
  • Ball Screw Actuator uses 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 efficient method of converting 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 instruments and medical systems.
     
  • Belt actuators work where a belt is carried between two pulleys and attached to the moving carriage, then as the belt rotates the carriage is pulled along the actuator. One of the pulleys is driven by a motor which is generally mounted perpendicular to the actuator and coupled using a flexible coupling. They offer a relatively low-cost alternative, as they inherently have a lower level of precision. Belt driven linear actuators are very good for long travel and high linear speed applications such as packaging and automated material handling systems.

Linear Actuators from Heason Technology

Linear Actuators supplied by Heason Technology have many benefits to your application:

  • Can be sealed to allow use in harsh/cleanroom/food production environments
  • Easy to mount
  • Easy to operate
  • Require little to no maintenance
  • Easy to install into an automated process
  • Don’t leak hydraulic fluid
  • Reliably work for a length of time even under the toughest of conditions

Some linear actuators that we can supply offer bespoke stroke lengths up to 915 mm and can provide full load forces as high as 6670 N (1500 lbf); they are also available in both DC (12, 24, 36) and AC (115, 230, 400) voltage variants.

Take a look at the full range of Linear Actuators on our website. Alternatively, if you’d like more information or need some advice, please contact our sales team on sales@heason.com or call us on +44 (0) 1403 792 300.

Article published on: 24/01/2020