Double Ring Axial Retention for Turbomachine Vanes

The single retaining ring is divided into two separate rings: a retaining ring for axial retention and a lock ring for preventing rotation and disengagement. This segmentation allows each ring to specialize in its function, with the lock ring providing additional stability under thermal and dynamic stresses without interfering with the axial retention function of the retaining ring.

The two rings are nested on the same groove, with the lock ring positioned radially outward from the retaining ring. Both rings share the same groove structure, creating a nested configuration where the lock ring reinforces the retaining ring's position and prevents disengagement while the retaining ring maintains axial retention of the vanes.

The anti-rotation function is extracted from the groove structure and implemented through the lock ring with its radially outward extending free end. This separate anti-rotation mechanism eliminates the need for precisely machined stop hooks on the groove, as the lock ring's geometry provides the anti-rotation constraint through its interaction with the groove's basic structure.

The lock ring provides localized anti-rotation functionality at its free end, which extends radially outward to engage with the groove structure. This local quality approach concentrates the anti-rotation function in a specific region rather than requiring precise machining across the entire groove structure, allowing for more relaxed manufacturing tolerances.

The lock ring serves multiple functions: it provides axial retention assistance, prevents rotation of the retaining ring, and prevents disengagement from the groove. This multi-functionality eliminates the need for separate protuberances or additional structural modifications to the disc, as the lock ring's geometry integrates all these retention and stabilization functions into a single component.

The anti-rotation and anti-disengagement functions are merged into the lock ring structure itself, rather than requiring separate protuberances on the rings or disc. The lock ring's radially outward extending free end combines multiple retention mechanisms in one element, simplifying the overall structure and reducing production costs by eliminating the need for additional complex features.

The lock ring's free end is designed to rotate slightly within the groove rather than being rigidly constrained by tight-tolerance stop hooks. This dynamic capability allows the lock ring to accommodate vibrations and thermal expansion without jamming, while still effectively preventing rotation of the retaining ring through its elastic engagement with the groove structure.

The engagement between the lock ring and groove transitions from a rigid, tight-tolerance mechanical fit to a more compliant elastic engagement. The lock ring's material elasticity and the larger engagement clearance allow for parameter changes during operation due to vibrations and thermal effects, preventing jamming while maintaining rotation prevention functionality.