As a precision transmission element, ball screws play an important role in the field of modern industrial manufacturing. Faced with a wide range of ball screw products on the market, how to accurately distinguish their differences has become a key proposition for purchasers and designers.
From the perspective of structural design, ball screws are mainly divided into two types: internal circulation and external circulation. The balls of the internal circulation screw circulate inside the nut through the reverser, with a compact structure and low friction loss, which is more suitable for high-precision application scenarios. The balls of the external circulation screw circulate through the duct outside the nut, with strong load-bearing capacity but large structural volume, and are often used in heavy-duty equipment. Structural differences directly determine the scope of application and mechanical properties of the product.
Subtle differences in manufacturing processes also affect the performance of the screw. High-precision ball screws usually use grinding technology, with a thread surface roughness of up to Ra0.4μm and a matching accuracy level of C0~C7. In contrast, ordinary screws mostly use rolling forming technology, with a surface roughness of about Ra6.3μm and an accuracy level concentrated in G5~G10. This process difference makes precision screws have obvious advantages in high-speed processing equipment.
In terms of performance parameters, lead accuracy and axial clearance are important indicators. The lead error of precision screws can be controlled within ±1μm, and the error fluctuation within the effective stroke does not exceed ±3μm. In the axial clearance indicator, the preloaded screw eliminates the gap by pre-tightening, and the repeat positioning accuracy can reach ±2μm, while the non-preloaded type has an inherent gap of 0.005~0.02mm.
When selecting a ball screw, it is necessary not only to compare the nominal parameters, but also to pay attention to material selection and heat treatment process. After vacuum quenching treatment, the surface hardness of high-carbon chromium bearing steel can reach HRC58~62, and the carburizing hardening process of the raceway can improve the wear resistance. These process treatments determine the service life of the screw under continuous heavy load conditions.
A deep understanding of the technical differences of ball screws will help companies accurately match equipment performance requirements and optimize product competitiveness. In the fields of precision manufacturing, automation equipment, etc., correct selection can provide key support for improving equipment performance.
