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 quite than a rotary one. As most typical electric motors are rotary, a linear actuator is used to convert rotary motion to linear motion.
The electrical 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 those actuators relying 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 allows them to operate as ‘stand-alone’ units, making them straightforward to mount into existing 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 can be 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.
Options of Linear Actuators
Linear Actuators have the following features:
Easy upkeep or maintenance free
Protection scores available for some models
Suitable for harsh environments
Rugged and reliable
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 together with:
Materials dealing with
Types of Linear Actuators
Picking the correct type of linear actuator to your motion application can 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 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 driven screw or an AC induction motor are essentially 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 embody agricultural equipment and guide 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 an ordinary 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 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 quick cyclic applications akin to machine instruments, scientific devices 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 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 offer a relatively low-cost various, as they inherently have a decrease level of precision. Belt pushed linear actuators are very good for lengthy travel and high linear pace applications akin to packaging and automated material dealing with systems.