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 quite than a rotary one. As most conventional electrical motors are rotary, a linear actuator
is used to transform 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 could 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 support either the lead screw, ball screw or belt pulleys. This then permits them to operate as ‘stand-alone’ units, making them simple to mount into current machines and eliminating the need to design/manufacture very expensive 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, similar to in an XY gantry style stage. In this case, a shaft or belt is usually used to keep the two actuators in sync with each other.
Options of Linear Actuators
Linear Actuators have the next features:
Easy maintenance or upkeep free
Protection ratings available for some models
Suitable for harsh environments
Rugged and reliable
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 together with:
Materials dealing with
Types of Linear Actuators
Picking the right type of linear actuator to 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 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 probably the most commonly used strategies to supply the rotary motion, as they're generally used in low price and low precision applications. The ability of the actuator to ‘back drive’ is reduced over ball screw actuators as a result of 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 include agricultural equipment and guide lift systems, the place 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 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 very environment friendly method of converting 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 fast cyclic applications similar to machine instruments, scientific devices and medical systems.
Belt actuators work where a belt is carried between two pulleys and connected to the moving carriage, then as the belt rotates the carriage is pulled alongside the actuator. One of the pulleys is pushed by a motor which is generally mounted perpendicular to the actuator and paired using a versatile coupling. They offer a relatively low-price different, as they inherently have a decrease degree of precision. Belt pushed linear actuators are excellent for lengthy journey and high linear pace applications akin to packaging and automated materials handling systems.