As many people know a ball screw is not a simple apparatus. In fact there are a number of components with the whole thing being called a ball screw assembly. The two principal parts of a ball screw assembly would be the nut and the screw.
A ball screw is a clever tool that allows a rotational screwing motion to be turned into a linear motion. Very little friction is generated during this process, and therefore there is a low level of energy loss. An additional consequence is that the ball screw apparatus erodes over a longer period of time. A ball screw is usually larger than a lead screw, because it has parts operating inside the shell of the ball screw nut. Within the casing of a ball screw nut a number of ball bearings which roll through the threaded interior of the barrel.
It should be ensured that it is impossible for particles of dirt to get into the interior of the ball screw. The ball bearings in the ball screw nut must be free to move along the grooves and any tiny speck of dust can affect their smooth motion. Ball screws are known to have long lifespan, and known to be very accurate. Unfortunately this performance will be reduced if particles become lodged in the mechanism. To prevent this factory craftsmen always avail of bellows and other methods in order to ensure that no small particles becoming fixed within the mechanism.
Ball screws have a reputation of being exceptionally accurate as they are manufactured to close tolerances. As a result of this they are used in areas that require high levels of precision, for example in robotics. Another application of these tools is in steppers, which are used to make semiconductors.
Many ball screws may be operated in reversed, or back-driven. This means that when typically the machine would be creating a turning energy and getting linear motion as an output, the user can also start out with a straight line movement and generate turning forces. This is possible due to the low friction contained within the ball screw, which prevents the components from jamming.
