Tolerance Ring Extended Portions Pivot Shaft Insertion
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Solution Overview
Problem
Conventional tolerance rings in hard disk devices have a distorted shape, making it difficult to insert the pivot shaft, which can lead to damage and contamination during assembly.
Innovation Solution
A tolerance ring with extended portions and small radius-of-curvature portions is designed to facilitate easier insertion of the pivot shaft by matching the shape of the circumscribed circle, preventing damage and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the tolerance ring is molded into a shape as close to a perfect circle as possible, then the shape uniformity is improved, but the manufacturing difficulty increases significantly
Solution Approach 1:
The patent introduces extended portions that protrude radially outward from the base at predetermined positions. These extended portions are formed in advance during molding, allowing the tolerance ring to be inserted into the carriage opening with proper alignment. The extended portions act as guide features that facilitate the preliminary alignment action before the pivot shaft insertion, resolving the contradiction by providing a practical molding approach that achieves functional shape uniformity without requiring perfect circular molding.
2Ease of manufacture
If the tolerance ring has an uneven shape with portions having smaller diameter, then the manufacturing is easier, but the pivot shaft insertion becomes difficult or disabled
Solution Approach 1:
The extended portions protruding radially outward serve as preliminary alignment features. When the tolerance ring is inserted into the carriage opening, these extended portions engage with corresponding features in the opening, establishing proper orientation and alignment before the pivot shaft is inserted. This preliminary action ensures that the pivot shaft can be smoothly inserted without encountering uneven diameter portions, resolving the contradiction between manufacturing ease and insertion ease.
Solution Approach 2:
The extended portions act as intermediary elements between the tolerance ring and the carriage opening. They mediate the insertion process by providing contact points that guide the tolerance ring into proper position, facilitating the subsequent pivot shaft insertion. This intermediary structure resolves the contradiction by creating a functional interface that accommodates both manufacturing practicalities and assembly requirements.
3Ease of operation
If the pivot shaft is forced to insert into the tolerance ring, then the insertion is completed, but damage and contamination occur
Solution Approach 1:
The extended portions perform the preliminary action of alignment and positioning before the pivot shaft insertion. By ensuring that the tolerance ring is properly oriented and seated in the carriage opening through engagement of the extended portions with the opening features, the pivot shaft can be inserted smoothly without forcing. This preliminary alignment action prevents damage and contamination, resolving the contradiction between insertion completion and damage prevention.
Solution Approach 2:
The extended portions provide beforehand cushioning by creating a controlled engagement interface with the carriage opening. This engagement absorbs misalignment and positioning errors before the pivot shaft insertion occurs, preventing forced insertion that would cause damage. The extended portions act as a cushioning mechanism that protects against insertion errors, resolving the contradiction between ensuring insertion completion and preventing damage.
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 improved tolerance ring enhances the insertion performance of the pivot shaft, ensuring reliable fixing between the carriage and pivot shaft while preventing damage and contamination.
Implementation Method 1
the tolerance ring is capable of elastically deforming in the carriage and is held in position such that a shape thereof along the winding direction takes a substantially circular shape
Data Source
AI summary
A tolerance ring includes: a base formed of a strip-like member substantially wound around into a shape; a plurality of projections provided along a winding direction of the base so as to protrude from an outer peripheral surface of the base in a radial direction of the base orthogonal to the outer peripheral surface; at least one extended portion extending from at least one of edge end portions in a width direction of the base, the width direction extending orthogonally to the winding direction and the radial direction. The extended portion extends from a region that includes at least one of a plurality of straight lines passing through respective contact points disposed between a section of the base and a circumscribed circle that circumscribes the section and extend in parallel with the width direction.