Calculation of spline connections as described in DIN 5480 with diameter centering

Diameter centered connections are centered in the outside or inside diameters. The pinion center root diameter with the shaft tip diameter is used for outside centering, and the pinion center root diameter and the pinion center tip diameter for inside centering. Here, the gear toothing is only used for rotational synchronization. The connection must therefore have sufficient flank clearance to prevent the center holes intersecting. Due to the small tolerances of the centering diameter, diameter-centered connections require increased manufacturing effort to limit the central displacement. This is why they are only used in exceptional circumstances.

To calculate diameter-centered connections:

1. In the Connections > Splines (Geometry and Strength) calculation module, open the Reference profile input window by clicking on its tab. Here, select the DIN5480 Major diameter fit option in the Reference profile drop-down in the Shaft and hub area.
2. Click the Tolerances tab to open the Tolerances input window. Check that no flag has been set in the checkbox to the right of Tip diameter deviation (upper/lower) and Root diameter deviation (upper/lower) input fields both for Shaft and hub. The program then prompts values from the DIN 5480 recommendations. For the tip diameter, the following apply:

• for outside centering, H6 for the shaft tip diameter and H11 for the pinion center tip diameter
• for inside centering, h11 for the shaft tip diameter and H7 for the pinion center tip diameter

For the root circle, the following apply:

• for outside centering h14 for the shaft root diameter and H7 for the pinion center root diameter
• for inside centering, h6 for the shaft root diameter and H14 for the pinion center root diameter

9H/9e is recommended for the tooth thickness tolerances.