Involute Splines Component Generator

Calculates and designs involute spline joints. Generator designs an applicable spline width, bending, and pressure loading are also checked. Only shaft teeth are part of the calculation because the stress in the shaft is greater than the hub teeth that have a greater root thickness.

Couplings with involute splines are suitable for transfers of great, cyclical, and shock torsional moments. This type is used both for fixed and for sliding couplings of cylindrical shafts with hubs. The use is similar as with parallel splines.

Advantages of the coupling:

Lower pressures than couplings with keys, higher loading capacity of the coupling
Lower wear of sliding couplings.
Suitable also for cyclical torsional moments.
Easy assembly and disassembly of the coupling.

Advantages of the coupling compared with parallel splines:

Higher number of teeth (lower pressures, higher loading capacity of the coupling, more uniform distribution of forces along the perimeter, option of fine adjustment of the hub on the shaft).
Lower weakening of the shaft, lower notch coefficient.
Economical lot production using a hobbing method.
High accuracy of production similarly as with accurate gears.

Disadvantages of the coupling:

Higher production costs than couplings with keys.
Higher notch coefficient than couplings with keys.
Difficult execution of alignment and perpendicularity of the coupling.
Nonparallelism of sides of the teeth causes additional radial forces in the coupling. These forces then try to open the hub.

The splined profile is shaped as involute toothing in the cross section, with basic angles of the profile 30°, 37.5° or 45°. It is centered to the outer diameter or sides of the teeth. Centering to the diameter is more accurate, centering to sides is more economical and is used much more frequently in practice The groove bottom can be flat or rounded.

Tip: See the Engineer's Handbook for used calculation formulas and other instructions for designing involute spline joints.