Linear actuators work by moving an object or piece of equipment in a straight line, moving an object extraordinarily accurately and repeatably if required. The first reason for designing a linear actuator into a system is for the necessity to move a payload in a linear fashion reasonably than a rotary one. As most standard electric motors are rotary, a linear actuator is used to transform rotary motion to linear motion.
The electrical motor is generally linked 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. A wide range of motor sizes can be mounted to those actuators relying on requirements.
Linear actuators have incorporated linear bearings that assist the moving payload, as well as rotary bearings that assist either the lead screw, ball screw or belt pulleys. This then permits them to operate as ‘stand-alone’ devices, making them straightforward to mount into existing machines and eliminating the need to design/manufacture very expensive custom parts. To extend the load capacity and stability of a linear actuator system, they are often paired up with the payload carried between them, akin to 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.
Options of Linear Actuators
Linear Actuators have the following 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 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:
Types of Linear Actuators
Picking the correct 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 utilized in numerous 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 probably the most commonly used methods to provide 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 as a result of 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 embrace agricultural equipment and manual 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 precept this is 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 efficient methodology 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 akin to machine tools, scientific devices and medical systems.
Belt actuators work the place a belt is carried between pulleys and hooked up to the moving carriage, then because the belt rotates the carriage is pulled along 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 relatively low-price different, as they inherently have a lower stage of precision. Belt driven linear actuators are excellent for lengthy journey and high linear pace applications reminiscent of packaging and automatic materials handling systems.