The term ‘linear motion’ is used in reference to components that are designed to move an object along a linear path. As their name suggests, linear motors are the most common way of achieving the desired result.
Linear Motors
A linear motor is much like any other electric motor that you have come across, but with one important difference – instead of the rotor spinning around the stator like in a normal motor, linear motors work by moving their stators relative to their rotors.
This design is what allows them to be used to create linear motion. Linear motors do not produce high levels of torque, but they can achieve very high speeds – which makes them perfect for creating motion along specific paths.
Linear actuators are basically just motors that have been designed to be used in a linear motion system.
Linear Actuators
While you could technically use an electric motor to create linear motion, it would not be advisable for two reasons: firstly, the torque produced by motors tends to be very high, which can lead to problems when they are used to drive things along a linear path.
Secondly, it will be difficult or impossible to use the motor’s speed controller, as motors tend to vary their speeds depending on the load (i.e. how heavy the object that they are trying to move is).
This means that you would either need an incredibly strong mechanical connection to contain all of that torque or would need to wire the motor with some kind of ‘brake’ system.
Because of these problems, it is often simpler to use a dedicated linear actuator instead. These devices are designed specifically for the purpose of driving objects along linear paths – so they don’t suffer from the same problems as electric motors and can be controlled very easily.
Linear motion is the key to many industrial machines, such as CNC routers and 3D printers.
Machine Components
Linear motion systems are also used in a variety of other machines, such as:
CNC Routers
These machines use linear components for X/Y axis movement. They often use ball screws and linear slides to move the cutting head in a straight line, and then rely on servo motors for positioning. CNC lathes may also be equipped with linear bearings instead of cross-slides for turning operations – although this is much less common.
3D Printers
Most 3D printers use a combination of linear actuators and regular stepper motors to create the movement needed to make their objects. Industrial Robots
Industrial robots also rely on linear motion to produce precise, accurate motion that is essential for making objects with repeatable dimensions.
In conclusion, linear motion is a system that uses linear components to create straight-line movement. There are various specialist devices available for this purpose, including linear motors and actuators. These devices often have a wide range of applications.