Industrial Linear Guides

Frequently asked questions — Linear Motion

• How do I choose between a shaft guide and a profiled rail guide?

  The choice depends on the precision and load requirements. Shaft bushings provide a cost-effective solution for unlimited strokes with a low coefficient of friction. For applications requiring greater rigidity and dynamic load capacities of up to 200 kN, the profiled rail guide family should be preferred. The latter are recommended where path accuracy is critical, while cylindrical shaft systems are suited to standard mechanical configurations.
• Which solution should be selected for very heavy loads?

  For very heavy loads, the range of profiled rail guides, whether ball or roller type, is the most suitable, supporting up to 200 kN. Alternatively, rack-and-pinion or roller systems are specifically designed for these high-stress environments. It is essential to check the static C0 and dynamic C load values to ensure the long-term durability of the installation, in addition to fitting shaft supports if the stroke length requires deflection to be limited.
• Should you choose linear bearings or separate ball bushings?

  The choice depends on ease of integration onto the frame. Ball bushings are the most economical linear guide system, requiring mounting on a ground shaft. Conversely, linear bearings integrate the bushing directly into a ready-to-mount housing, thus making direct fixing easier. If time savings during assembly and integrated sealing are required, bearings such as LHFR or SBR are preferable to standalone bushings.
• What are the criteria for selecting the right guide shafts?

  Selection is based on compatibility with bushing diameters, standardised from 8 to 80 mm. It is necessary to use ground shafts in Cr40 or Cf53 steel, hardened to HRC 60-62 to guarantee precision class h6. For mounting, the use of shaft supports from the SHF or SK series is recommended to ensure stable fixing, while intermediate supports of the SH or MSH type are essential to limit bending over long strokes.
• What precautions should be taken for guides in contaminated or food-grade environments?

  In contaminated environments, the use of synthetic greases is recommended, as opposed to lithium greases intended for standard service. For cleanroom or food-grade applications, stainless steel variants are available to limit corrosion. It is also advisable to add accessories such as double-lip seals or protective bellows to preserve the service life of the raceways and ensure the proper operation of the bushings or rails.