What is linear motion control? Explore linear motion options
Used widely in industrial automation, linear motion systems are for one specific type of motion control: moving parts of a machine in a controlled manner in a straight line. Linear motion applications include the power of machine tools, assembling and packing, testing and inspection, and robotics systems. We look in more detail at what is linear motion control and different linear motion systems, including some of the more common drive technologies used for linear motion, such as lead screws and ball screw linear actuators.
What is a linear motion control system made up of?
Linear motion systems usually consist of a controller (a computer or a stand-alone electronic device), a motor, and an actuator, which moves the load. When we talk about linear motion, the specification is for the load to be moved in a straight line, either up and down or back and forth. This sounds straightforward, but when you consider that a standard solution for moving small loads accurately and with precision would be an electric motor, because of the rotary nature of the motor, the actuator must be able to turn rotational movement into linear movement.
What drive technologies are there for linear motion systems?
There are two common solutions for drive technologies: ball screw linear actuators and lead screw drives. But what are they, and how do they convert movement into linear movement?
Ballscrew linear actuators:
A ball screw linear actuator converts rotational motion into linear movement using a threaded shaft and ball bearings. The shaft of the ball screw includes a helical path around which the ball bearings move, behaving like a screw but with very little friction; the ball assembly behaves as the nut, with the threaded shaft acting as a screw.
Manufactured to higher tolerances than some of the other linear motion drive options, ball screw linear actuators are a popular choice for high-precision applications where accuracy and control are critical. The main drawback of ball screw linear actuators is that, due to the need for the balls to be recirculated, the overall size of the device is larger and bulkier than other options.
Lead screw actuators:
Much like ball screw linear actuators, lead screws are designed in the same way, with the difference being that rather than having ball bearings to provide a frictionless motion, the lead screw’s thread maintains direct contact with the moving nut component. This means that while higher forces are possible with a lead screw, the added friction creates the need for more power from the motor.
However, the added friction of the lead screw can lead to less efficient systems. This, in turn, may lead to increased running and maintenance costs over time. The other advantage of lead screws is that they are less prone to being back-driven and do not require an additional braking component in the way that ball screw linear actuators do for some linear motion applications.
Find linear motion systems from Matara
Here at Matara, there are an extensive range of options for linear motion control, including lead screws and ball screw linear actuators with either rolled ball screws or ground ball screws. We also offer linear guides and rails to be used for support and guidance in linear motion systems, which are designed to be used in conjunction with a screw assembly or an alternative linear motion drive.
If you have any questions about our linear motion systems, then be sure to contact us, and a member of our team will be happy to help. For more information about linear motion systems and all we do here at Matara, check out our case studies and technical articles.