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 necessity to move a payload in a linear fashion relatively than a rotary one. As most conventional electric motors are rotary, a linear actuator is used to transform 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. Quite a lot of motor sizes can be mounted to these actuators relying on requirements.
Linear actuators have incorporated linear bearings that assist 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’ gadgets, making them easy to mount into present machines and eliminating the necessity to design/manufacture very pricey customized 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 two actuators in sync with each other.
Options of Linear Actuators
Linear Actuators have the next features:
Easy maintenance or maintenance free
Protection ratings 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 including:
Types of Linear Actuators
Picking the proper type of linear actuator to your motion application will 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 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 price and low precision applications. The ability of the actuator to ‘back drive’ is reduced over ball screw actuators because of the low efficiency 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 include agricultural equipment and guide lift systems, where 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 round a ground screw thread. In principle 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 really environment friendly method of changing 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 comparable to machine instruments, scientific instruments 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 utilizing a versatile coupling. They offer a comparatively low-cost various, as they inherently have a decrease degree of precision. Belt driven linear actuators are very good for long journey and high linear pace applications resembling packaging and automated material handling systems.