Linear drives are devices powered by electricity that convert screw motion into progressively linear motion. They are used in both professional equipment and home automation solutions. In this article, we will explain how to make the right choice in favor of a particular linear actuator model.
What Are the Principles of a Linear Actuators’ Operation?
To begin, let’s talk about the internal organization of linear actuators.
As a rule, the most common option is when the main moving element of the drive is a retractable slider moving along the guide. To change its direction in modern linear drives, an automatic switcher is used, which changes the polarity of the power supply.
As for limiting the slider’s movement, the actuator is equipped with built-in limiter switches (they are installed inside the actuator, directly on the slider). These switches are triggered when the slider reaches the extreme positions inside the case. One of the switches serves to stop the slider in the extended position, and the other – in the retracted position. Additionally, while one of the limiters is activated, it also blocks the further movement in the respective direction.
In addition to the slider, driven by the transmission (screw-type wormgear), the case contains an electric motor, gearbox, and control system.
The drives used in linear actuators, in most cases, are powered by 12 or 24V DC sources (although there is a variety of other options available).
To achieve the required speed and force, a mechanical gearbox is installed between the motor shaft and the screw gear. Gearbox modulates the ratio between the motor’s and wormgear’s rotation speed, which ultimately affects the final linear motion and the force of the slider: the greater the gear ratio, the greater the force and lower the speed. The helical gear also influences the ratio of speed and effort – the smaller its pitch, the greater the effort and the slower the speed of slider movement.
Despite the fairly simple design, linear actuators have high accuracy, are environmentally friendly, and consume a minimum of resources. It is because of the combination of these advantages, that today there are a lot of options for using linear actuators: ranging from adjusting the seat height to hatches in aerospace machines.
Selecting Linear Actuator: Criteria of the Choice
So, what characteristics you need to pay attention to when choosing a linear actuator? Here is the basic list of parameters:
- Stroke length (from the point of view of design, stroke length depends on the length of the slider and the actuator housing);
- Movement speed (as a rule, it is directly proportional to the stroke length);
- Displacement force (measured in kg/s);
- Drive voltage (there are drives that are powered from a DC source with a voltage of 12V or 24V, as well as drives that are powered directly from a 220V outlet);
- Motor placement (longitudinal/transverse).
We also recommend paying attention to the degree of the case’s environmental protection (IP code marking).
As you can see, choosing a linear actuator is not so difficult. If you are in search of reliable but at the same time cheap 24V or 12V actuators, visit our website. It presents the widest range of models for both industrial use and amateur installations. Note also that all of them can be customized to the individual needs of the customer.