The first thing to know is that a linear actuator does exactly what its name implies: it actuates (or ‘moves’) in a linear (or ‘straight’) fashion. There are many different ways that a linear actuators motor can do this, and their motion is commonly achieved with a rod extending and retracting, or a slider that moves on a track. It’s motion is created by using a Lead-screw. The screw turns either clockwise or counter-clockwise and this causes the shaft, which is basically a nut on the screw to move up and down the screw as the screw turns. This is what converts rotary motion from the electric motor to Linear motion.
The motors used are either AC or DC motors, most however run on 12v dc. To make a Linear Actuator go in the opposite direction you simple reverse the wires from the Linear Actuator (reverse polarity) from the battery or power supply. This is typically done through a switch that automatically reverses the polarity to the motor for you. Different speeds and forces are achieved by using different gear ratio’s inside the Linear Actuator gearbox system. Please remember in a linear actuator, force and speed trade off against each other. That means if you want high force you have to settle for a lower speed than if you require lower force. This is because the only constant in a Linear Actuator is the Motor speed and force for a given input voltage.
To make our linear actuator shaft stop when it gets to the end of the stroke, our products have built-in limit switches or micro switches as they are sometimes known. These limit switches are inside the main shaft and are nothing more than a small switch that is triggered by the nut inside that slides up and down the screw. There is one for the top extended position and one for the lower retracted position. For more information on this, check out our Blogs page.