Rieter

Spindle structure

Index

Fig. 18 – Cap wharve

The spindle consists of two distinctly separate parts, spindle center shaft (4) and enclosed bearing housing (7). Nowadays the center shaft is made from an aluminum alloy and is slightly tapered (e.g. 1:64). It has a tube coupling at the top (also at the bottom on large spindles) to ensure that the tube is firmly seated on the shaft.

The bottom end of the shaft takes the form of a wharve (5). This is a cap wharve, i.e. it is hollow and can therefore be fitted over the spindle collar accommodated in the bearing housing (Fig. 18). The tensile forces generated by the drive belt therefore act directly on the bearing, which favorably influences the smooth running of the spindle. However, the size of the wharve is important as well as its shape. If its diameter can be kept small, equally high spindle speeds can be achieved at lower drive speeds (cylinder/belts). This results in lower energy consumption. However, in order to ensure that the drive belt rotates the spindle slip-free, the diameter of the wharve must also not be too small. Wharve diameters of 19 to 22 mm are customary at present.
Bearing section (7) is bolted firmly to ring rail (6) by nut (8) (Fig. 17).