Extra slot gives extra strength

Problem: . Not only is this very straightforward, requiring very little tooling, but it also allows the hub to be positioned very finely allowing the best alignment. However, in situations where there is a need to maximise the torque capacity of the component/shaft joint, it may be necessary to use a set screw. The problem with set screws is that they can quite easily damage the shaft which could present future problems with regard to maintenance. Solution: In a quest to improve the torque capacity of clamp hubs, engineers at the Reliance Gear Company put FEA into action. The program was used to assess how normal clamps work and how the two-point clamping force could be improved upon. One design iteration called for an additional slot to be cut at 90 degrees to the first. Upon initial inspection of the FEA model, the engineers discovered that this configuration still only needed a single grub screw to provide consistent pressure around the whole of the clamp/shaft interface, even though one of the slots is parallel to the ‘tightening’ direction of the grub screw. Since the discovery the company has applied for a patent. Applications: The Reli-a-grip clamp has been put into action by the company on its Reli-a-flex coupling which was the subject of a Eureka feature in June 1998. The resultant combination allows the Reli-a-flex cross-slit clamp hub couplings to achieve the same rated torque as set screw couplings – without any damage to the shaft. MF