Elastic Joint Translating Spherical Hinge Friction Reduction
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Solution Overview
Problem
Existing force and moment sensors with rigid or statically determined structures are compromised by friction in translating spherical hinges, leading to reduced sensitivity and accuracy in measurements.
Innovation Solution
An elastic joint with a translating spherical hinge is introduced, utilizing flexible beams or wires that allow four degrees of freedom, including translation, rotation, and torsion, to create a more accurate and sensitive force and moment sensor with reduced friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional translating spherical hinges with smooth or ball bearings are used, then the structure is mechanically stable, but friction increases which reduces measurement sensitivity and accuracy
Solution Approach 1:
The patent replaces the traditional mechanical hinge system with smooth or ball bearings that generates friction with an elastic joint system composed of flexible beams or wires. This substitution eliminates the harmful friction effect while maintaining the necessary mechanical functionality for four degrees of freedom, thereby improving measurement sensitivity and accuracy.
Solution Approach 2:
The patent employs flexible beams or wires as the core elastic elements to create a translating spherical hinge without mechanical contact. These flexible elements bend and deform elastically to provide the required degrees of freedom, eliminating the need for bearings and thus removing the source of friction that degrades measurement quality.
2Stability of the object's composition
If rigid sensors with statically determined structures are used, then structural stability is maintained, but measurement sensitivity and accuracy deteriorate due to friction in translating spherical hinges
Solution Approach 1:
The patent transitions from a rigid, statically determined structure to a dynamic elastic structure that can adapt its stiffness characteristics. The elastic joint with flexible beams or wires provides structural stability through elastic restoration forces while simultaneously enabling sensitive measurements by allowing small deformations under load, thus resolving the contradiction between stability and sensitivity.
3Adaptability or versatility
If complex mechanical hinge systems are used to achieve four degrees of freedom, then the translating spherical hinge functionality is achieved, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent uses flexible beams or wires arranged in specific configurations to achieve four degrees of freedom (three rotations and one translation) without complex mechanical assemblies. The flexibility and elastic deformation of these simple elements provide the necessary kinematic capabilities, significantly reducing device complexity and manufacturing costs compared to traditional multi-component hinge systems.
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 elastic joint with a translating spherical hinge enhances the sensitivity and accuracy of force and moment measurements while reducing construction costs and friction, enabling precise and economical dynamometric hubs for various applications.
Implementation Method 1
an elastic joint with a translating spherical hinge, comprising a series of elastic elements (12), or at least three beams or two elastic laminae (12)
Implementation Method 2
The articulation of the joint (10) takes place between the axial element (14) and the support (16) and allows four degrees of freedom, i.e. the translation of the axial element (14) in the direction of the orthogonal axis (11) and the spatial rotation of the axial element (14)
Data Source
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Figure 3A~3C
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AI summary
An elastic joint with a translating spherical hinge, i.e. a spherical hinge with a sliding joint, comprising an elastic articulated plane (13), a support (16) to which the elastic articulated plane (13) is rigidly constrained, and an axial element (14), positioned according to an axis (11) orthogonal to the plane (13), wherein the elastic articulated plane (13) comprises a series of elastic elements (12) arranged with a first end facing and rigidly connected to the axial element (14), and wherein the elastic elements (12) are flexible in any vertical plane comprising the axis (11) and in the horizontal plane (13) to allow four degrees of freedom or, respectively, the translation of the axial element (14) in the direction of the orthogonal axis (11) and the spatial rotation as well as the torsion around the axis (11). The joint according to the invention is particularly suitable for perfecting a force and moment sensor.