Resin Retainer Fall Prevention for Motion Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resin-based rolling element retainers in motion guide apparatuses can warp or distort, leading to increased opening widths and potential rolling element ejection due to molding conditions, compromising the retention of rolling elements.
Innovation Solution
Incorporating a fall prevention portion at the center of the retaining portion to reduce the opening width between retaining portions, ensuring that rolling elements are securely retained even if warping or distortion occurs during molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the rolling element retainer is made of resin, then the ease of manufacture is improved, but the shape stability deteriorates due to warping or distortion
Solution Approach 1:
The fall prevention portion is designed in advance during the molding process to preemptively counteract the warping or distortion that may occur. By incorporating this preventive structural feature before the warping actually happens, the opening width is maintained within acceptable limits even when warping occurs, thus resolving the contradiction between ease of resin manufacturing and shape stability
Solution Approach 2:
The fall prevention portion acts as a compensatory measure that cushions against the harmful effect of warping. By designing the retaining portion with this additional protective feature, the patent compensates for the potential shape instability of resin materials, ensuring that the opening width does not exceed the rolling element diameter even when warping occurs
2Device complexity
If the retaining portion is designed with a simple structure, then the device complexity is reduced, but the reliability deteriorates due to increased opening width from warping
Solution Approach 1:
Instead of making the entire retaining portion complex, the fall prevention portion is localized to specific areas where warping would most affect the opening width. This localized approach maintains simplicity in the overall structure while providing enhanced reliability at critical locations, resolving the contradiction between device complexity and reliability
3Reliability
If the opening width is reduced to prevent rolling element ejection, then the reliability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The fall prevention portion is incorporated during the molding process to preemptively ensure that the opening width remains within acceptable limits. This preliminary structural feature reduces the need for post-manufacturing adjustments and lowers the overall manufacturing precision requirements while maintaining reliability
Solution Approach 2:
By changing the geometric parameters of the retaining portion to include the fall prevention feature, the patent achieves reliable rolling element retention without requiring extremely tight manufacturing tolerances. The structural design compensates for normal manufacturing variations, thus improving reliability without excessively increasing manufacturing precision requirements
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 fall prevention portion effectively maintains the opening width below the rolling element diameter, preventing ejection and ensuring reliable retention of rolling elements, even under conditions of warping or distortion in the retaining portions.
Implementation Method 1
A plurality of rolling elements is placed between the rolling element rolling portion of the track rail and the loaded rolling element rolling portion of the block in such a manner as to be capable of rolling motion. When the block moves relatively to the track rail in the length direction, the rolling elements between the block and the track rail perform rolling motion.
Data Source
AI summary
A motion guide apparatus ensures that a retaining portion retains a rolling element. A rolling element retainer having retaining portions that prevent a rolling element from falling out of a movable body, the retaining portions extending along a loaded rolling element rolling portion, is incorporated in the movable body of the motion guide apparatus. End plates are formed integrally with the retaining portions. Fall prevention portions to reduce the widths of openings between the retaining portions are provided to center parts of the retaining portions in a length direction thereof. The fall prevention portions are padding portions integrated with the retaining portions, the padding portions rising in such a manner as to reduce the widths of the openings, and/or projections integrated with the retaining portions, the projections touching the movable body in such a manner that the center parts of the retaining portions bend toward a track member.