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 fairly 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 related 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 may be mounted to these actuators depending on requirements.
Linear actuators have incorporated linear bearings that help 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’ gadgets, making them straightforward to mount into current machines and eliminating the necessity to design/manufacture very expensive custom 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 often used to keep the 2 actuators in sync with each other.
Features of Linear Actuators
Linear Actuators have the following features:
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 utilized in various applications that require a load to either be lifted, lowered, pushed, pulled, rotated or positioned. Linear Actuators are utilized in industries including:
Packaging
Food processing
Industrial vehicles
Factory automation
Materials dealing with
Clean energy
Printing
Automotive
Machine device
Marine
Aerospace
Defence
Pharmaceutical
Types of Linear Actuators
Picking the right type of linear actuator to your motion application can assist you achieve the very 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 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 probably the most commonly used methods to provide 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 embrace agricultural equipment and manual 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 very similar to a normal 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 methodology 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 resembling machine tools, scientific instruments and medical systems.
Belt actuators work where a belt is carried between pulleys and connected to the moving carriage, then as 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 utilizing a flexible coupling. They offer a comparatively low-price various, as they inherently have a lower stage of precision. Belt driven linear actuators are very good for long journey and high linear pace applications resembling packaging and automatic material dealing with systems.