Flexible Pseudo-Parallelogram Guidance for Fatigue-Resistant Translation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Parallelogram guidance systems exhibit poor resistance to fatigue and mechanical stresses, leading to short lifespan due to stress concentrations at anchoring points, which limits their service life.
Innovation Solution
A flexible pseudo-parallelogram guidance device with non-constant section beams and a monolithic structure, featuring curved beams with maximum stress at anchor points and minimum at the center, and variable thickness to homogenize stress distribution, reducing stress concentrations and enhancing fatigue resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flexible beams are used in parallelogram guidance systems, then the guidance provides pure translational movements, but the resistance to fatigue and mechanical stresses deteriorates due to stress concentrations at anchoring points
Solution Approach 1:
The beam cross-section is varied along its length, with maximum section at the anchoring points and minimum section at the center. This local variation in geometry concentrates material where stresses are highest (at the anchoring points) and reduces material where stresses are lowest (at the center), thereby homogenizing the stress distribution and improving fatigue resistance
Solution Approach 2:
The beam's geometric parameters (cross-sectional area, moment of inertia) are changed along its length to optimize stress distribution. By adjusting the section modulus variable along the beam, the design transforms from uniform stress concentration to homogeneous stress distribution, significantly improving fatigue life
2Reliability
If the beam section is increased at anchoring points to reduce stress concentrations, then the fatigue resistance improves, but the weight and material usage increase
Solution Approach 1:
Rather than uniformly increasing beam dimensions throughout, the invention applies increased section only where needed (at the anchoring points) and reduces it where not needed (at the center). This localized quality variation achieves the required fatigue resistance while minimizing overall material usage and weight
Solution Approach 2:
The beam incorporates curved geometry with specific radius of curvature that optimizes stress distribution. The curved shape, combined with variable section, creates a more efficient stress path compared to straight beams, reducing peak stresses without requiring excessive material
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly increases the service life of the guidance system by distributing mechanical stresses homogeneously, reducing stress concentrations, and maintaining precise translational movements with high resistance to fatigue.
Implementation Method 1
the guidance is ensured in particular by the bending of the beams causing mechanical stresses
Implementation Method 2
Said beams have for example non-constant sections, the section being for example minimum in the center and/or maximum at the level of the fixing points of said beams
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The device, which is capable of translationally guiding a component, comprises: - two pairs (30, 30') of flexible beams (31, 32, 31', 32') that are symmetrical relative to an axis (20), the two beams of a pair being curved and not parallel to each other; - a central mechanical structure (3) intersected by said axis (20), on which structure said pairs of beams are fixed at fixing points (B, C, A', D'), said mechanical structure being capable of being mechanically linked to said component; - two mechanical interfaces (4, 4') each having a pair of beams fixed thereto at fixing points (A, B, C', D'), said interfaces being capable of being fixed on a mechanical structure; the two sets of fixing points (A, B, C, D, A', B', C', D') located either side of said axis of symmetry each forming a parallelogram, the guidance of said component being obtained by a force exerted on said central mechanical structure parallel to said axis of symmetry.