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 right into a system is for the need to move a payload in a linear fashion relatively than a rotary one. As most standard electrical motors are rotary, a linear actuator is used to transform rotary motion to linear motion.
The electric motor is generally linked 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 could be mounted to these actuators relying on requirements.
Linear actuators have incorporated linear bearings that support 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’ units, making them straightforward to mount into present machines and eliminating the necessity to design/manufacture very pricey 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, resembling 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.
Features of Linear Actuators
Linear Actuators have the next features:
Easy upkeep or upkeep 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 numerous applications that require a load to either be lifted, lowered, pushed, pulled, rotated or positioned. Linear Actuators are utilized in industries together with:
Types of Linear Actuators
Picking the correct type of linear actuator to your motion application might 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 various 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 pushed screw or an AC induction motor are essentially the most commonly used methods to supply the rotary motion, as they’re generally used in low value 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 can be an advantage as it helps to keep the payload stationary whilst not in motion. Applications include agricultural equipment and handbook 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 around a ground screw thread. In precept this is similar to a standard 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 supply the rotary motion. Ball screw actuators are well suited to repeatable indexing and quick cyclic applications equivalent to machine instruments, scientific instruments and medical systems.
Belt actuators work where a belt is carried between pulleys and connected to the moving carriage, then because 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 matched using a flexible coupling. They provide a relatively low-cost alternative, as they inherently have a decrease degree of precision. Belt pushed linear actuators are excellent for long travel and high linear pace applications such as packaging and automated material dealing with systems.