The basic difference between Threaded Rod vs ball screw […]
The basic difference between Threaded Rod vs ball screws is that a ball screw uses ball bearings to eliminate the friction between the nut and screw and Threaded Rod do not. The screw and nut on a ball screw have matching helical grooves that allow ball bearings to re-circulate in those races, and are typically semi-circular in shape to accept the spherical ball bearing. Threaded Rod use deeper helical threads and a mating nut, which is usually made of a polymer composite or bronze. The rolling nature of ball screws eliminates the sliding friction associated with Threaded Rod.
Each type of actuator has its advantages and disadvantages. Before you can decide on what type of screw to use, you need to understand how the distinct characteristics of each match your specific application.
The advantages of a leadscrew are:
Large load carrying capability
Simple to design
Easy to manufacture; no specialized machinery is required
Large mechanical advantage
Precise and accurate linear motion
Smooth, quiet, and low maintenance
Minimal number of parts
Most are self-locking
The disadvantages are that most are not very efficient. Due to the low efficiency they cannot be used in continuous power transmission applications. They also have a high degree of friction on the threads, which can wear the threads out quickly. For square threads, the nut must be replaced; for trapezoidal threads, a split nut may be used to compensate for the wear.