Flexure-Based Gib Preload Mechanism for Zero-Clearance Guides
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing preload mechanisms in translation systems require adjustments to remove play and fit clearances, which are prone to manufacturing errors, wear, and misalignments, and are not efficient in maintaining consistent preload values.
Innovation Solution
A flexure-based preloading mechanism that uses a gib with a protrusion and recess design, where the gib is flexibly movable via a flexure, providing a predefined preload force by varying its dimension between neutral and flexed states, eliminating the need for adjustments and optimizing performance through precise machining techniques like Wire EDM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solid preload with adjustable spacers is used, then system stiffness is high, but preload control requires torque adjustment and is sensitive to manufacturing errors and wear
Solution Approach 1:
The flexure mechanism automatically maintains the optimal preload force through its elastic deformation characteristics. The gib flexibly moves within the recess, self-adjusting to thermal expansion and misalignment while consistently applying the designed preload force without requiring external adjustment mechanisms or torque control.
Solution Approach 2:
The patent changes the physical state of the gib from rigid to flexible by introducing a flexure mechanism. This allows the gib to elastically deform and absorb variations in clearance, thermal expansion, and manufacturing tolerances while maintaining consistent preload force, thereby improving reliability without sacrificing stiffness.
2Reliability
If spring preload is used, then misalignment and thermal expansion are forgiven, but system stiffness is reduced and design becomes more complex
Solution Approach 1:
The flexure is applied locally to the gib rather than making the entire preload mechanism flexible. This localized flexibility allows the gib to accommodate misalignment and thermal expansion in specific areas while maintaining overall system stiffness through the rigid connection to the translating surfaces.
3Manufacturing precision
If adjustment mechanisms are used to remove play, then fit clearances can be controlled, but device complexity increases and adjustments are prone to wear and manufacturing errors
Solution Approach 1:
The flexure mechanism eliminates the need for external adjustment mechanisms by incorporating the clearance compensation function directly into the gib structure. The flexible gib automatically adapts to clearance variations through elastic deformation, removing play without requiring additional adjustment components or procedures.
4Force
If gib screws are tightened to apply preload, then preload force can be controlled, but over-constraining the system may occur and requires specific tightening sequences
Solution Approach 1:
The flexure mechanism eliminates the need for manual preload adjustment and tightening procedures. The gib automatically applies the designed preload force through its elastic deformation when installed, removing play and preventing over-constraining without requiring operator intervention or specific tightening sequences.
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 flexure-based mechanism simplifies translation mechanisms by removing the need for preload adjustments, ensuring consistent preload forces and reducing unwanted play between surfaces, thereby enhancing system performance and reliability.
Implementation Method 1
the gib is flexibly movable via a flexure; wherein a dimension of the recess varies based on a flexing of the gib; when the gib is in a neutral state, the dimension of the recess is smaller than a corresponding dimension of the protrusion; when the gib is in a flexed state, the dimension of the recess is larger than the corresponding dimension of the protrusion
Data Source
Figure 1~3
Figure 4A~4B
Figure 5A~5B
AI summary
A preloading mechanism including: a first part having a protrusion; and a second part having a recess that matches the protrusion; wherein the recess includes a gib that is flexibly movable via a flexure; wherein a dimension of the recess varies based on a flexing of the gib; when the gib is in a neutral state, the dimension of the recess is smaller than a corresponding dimension of the protrusion; when the gib is in a flexed state, the dimension of the recess is larger than the corresponding dimension of the protrusion; and when the protrusion is inserted into the recess, the gib is in an interfering state, providing a preload force for eliminating a clearance between a surface of the protrusion and a corresponding surface of the recess, wherein the flexing of gib in the interfering state is between those of the neutral state and flexed state.