Flexible Disc Thickness Profile for Rotorcraft Transmission Shaft Misalignment

The patent applies local quality by varying the thickness of the flexible disc non-uniformly: the transition zone has minimum thickness at the periphery to prevent breakage, while the central zone has greater thickness to maintain stiffness. This localized thickness distribution allows different regions to serve different functions - the periphery accommodates misalignment without stress concentration, while the center maintains structural rigidity for power transmission.

The patent changes the geometric parameter of thickness distribution across the flexible disc. By defining a specific thickness profile where e(r) varies with radial position, the design optimizes both lifespan and stiffness. The thickness transitions from minimum at the peripheral collar to greater thickness toward the center, creating an optimal balance between flexibility for misalignment compensation and stiffness for mechanical strength.

The patent addresses this contradiction by applying local quality through non-uniform thickness distribution. The transition zone has minimum thickness at the periphery where it needs to be flexible for misalignment compensation, while avoiding stress concentration by not having uniform thinness throughout. The central zone maintains greater thickness to handle stress, preventing breakage while preserving adaptability.

The patent applies preliminary action by pre-shaping the flexible disc with a specific thickness profile during manufacturing. This predetermined geometric configuration prepares the disc to distribute stresses favorably during operation, preventing stress concentration at the transition zone before misalignment occurs. The pre-designed thickness variation ensures that when deformation happens, stresses are distributed evenly rather than concentrating at weak points.

The patent resolves this contradiction through local quality by making different regions of the flexible disc have different thicknesses. The peripheral transition zone remains thin to maintain flexibility and ease of operation for misalignment compensation, while the central zone has greater thickness to provide resistance to mechanical stresses from power transmission. This localized differentiation allows both flexibility and strength to coexist in appropriate locations.

The patent applies another dimension by transitioning from a uniform two-dimensional disc to a three-dimensional structure with variable thickness. This adds the thickness dimension as a design parameter, allowing the disc to have thin regions for flexibility and thick regions for strength simultaneously. The thickness variation creates a gradient structure that optimizes both ease of operation and mechanical resistance.