The difference between ball screw and trapezoidal screw

Machine manufacturer's problem

"Ball Screw and Trapezoidal Screw are not interchangeable in many cases, and there is always a trade-off between accuracy, stiffness and load capacity. I also heard that there is not necessarily a complete correspondence between specification and performance. I hope to compare Mature perspectives to understand the true difference."

There are some differences between the application of ball screw and trapezoidal screw. The original equipment manufacturer's application system often needs "just right" products, and the Lead Screw is often the right choice. Trapezoidal screw products can easily be adapted to specific applications to achieve the desired performance while keeping costs to a minimum. In some cases, life testing needs to be performed during the design phase, but for OEMs, performing such additional work in the early stages can help reduce product costs. Ball screws can run continuously, withstand much higher loads, and achieve faster speeds, which adds to the cost. For the end user, the ball screw has good predictability and is therefore the best choice to ensure rapid integration and reliability. For example, factory automation systems rely heavily on ball screw technology. Of course, there are many original equipment manufacturer application systems that also require ball screws, such as the machine tool industry. For OEMs, it is performance and cost that determine technology, not predictability.

The main difference between a ball screw and a trapezoidal screw is how the load is carried between moving surfaces. Ball screws use recirculating ball bearings to minimize friction and improve efficiency, while trapezoidal screws use a low coefficient of friction between sliding surfaces. Therefore, the trapezoidal screw generally does not achieve the ball screw efficiency (about 90%). A simple analysis of the tribological mechanism (research on wear and friction) reveals that the predictability of sliding friction is necessarily lower than that of a recirculating ball technology. The fatigue life equation (such as L10 life) is very reliable within its scope of application. In summary, ball screws and trapezoidal screws differ in their ability to predict performance and longevity, so there are fundamental differences in their application areas.

Although ball screws have a variety of advantages (load, stiffness, efficiency, duty cycle, predictability), they are costly. Although they are more cost-effective than other translational Linear Motion solutions, the design of the ball screw is more complex, requiring hardened precision Bearing surfaces and a ball circulation device. The size of the trapezoidal screw is very small, the design is very flexible, the noise is very small under the condition of correct use, and the corrosion resistance is good. The self-locking function can be configured to meet the vertical application requirements. They play an important role in many application areas, and of course, there are some limitations.