THK Roller Follower Model RNAST RNAST R SERIES represents a specialized class of linear motion components engineered for applications demanding high rigidity, exceptional load capacity, and smooth, precise guidance under challenging conditions. This series incorporates a stud-type design with a thick outer ring and utilizes high-precision, crowning-profiled rollers as the rolling elements. The fundamental construction features a stud shaft integrated with a roller unit, which is assembled with a full complement of rollers held securely by a retainer. This design eliminates the need for cages or separators, maximizing the number of load-bearing rollers in direct contact with the raceway. The stud is manufactured with a precision-ground thread for straightforward and secure mounting into a machine frame or housing, while a hexagon socket in the stud’s end facilitates easy installation and adjustment.

The technical features of the RNAST R SERIES are defined by its robust architecture and material science. The rollers themselves are through-hardened and subjected to a precision crowning process. This crowning is a critical feature, as it prevents stress concentration at the edges of the rollers, ensuring a more even distribution of load across the roller profile and significantly extending the component’s service life by minimizing edge-loading and the risk of brinelling. The outer ring and rollers are typically made from high-carbon chromium bearing steel, heat-treated to achieve a high surface hardness that provides excellent resistance to wear and indentation. The series is available with various sealing options, including standard seals or heavy-duty seals with steel shields, to effectively exclude contaminants like dust, chips, and moisture, while retaining grease for long-term, maintenance-free operation.

Performance advantages are substantial, stemming directly from its full-complement roller design. The primary benefit is an exceptionally high radial load capacity compared to similarly sized ball-based followers. This makes the RNAST R SERIES ideal for withstanding heavy shocks and substantial static or dynamic loads. The rigid stud construction and large roller diameter contribute to high moment load capacity and stiffness, minimizing deflection under load and ensuring positional accuracy. The rolling friction of the rollers provides smooth, low-friction motion, which is crucial for reducing drive power requirements and preventing stick-slip phenomena in precision applications.

Typical applications for the THK RNAST R SERIES are found across industries where robust, reliable linear guidance is paramount. In industrial machinery, they are extensively used in the cam follower role for heavy-duty cam mechanisms, in the guide rollers for large linear slides and transfer systems, and as support rollers for heavy doors or lifting platforms. Within automotive manufacturing systems, they serve as guide and tracking rollers in welding robots, pallet conveyors, and heavy assembly jigs. In the realm of precision equipment, their high rigidity and smooth motion make them suitable for use in precision indexing tables, large-scale coordinate measuring machines, and specialized machine tools where high load and high accuracy must coexist. The series’ durability and sealing effectiveness make it a dependable choice for harsh environments common in these sectors.