Tolerance Ring End Tab Designs Prevent Interlocking
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Solution Overview
Problem
State-of-the-art tolerance rings for actuator arms in hard disk drives often interlock during shipping and handling, making separation labor-intensive, time-consuming, and prone to damage.
Innovation Solution
The tolerance ring design incorporates features such as hook-shaped tabs, non-linear gap configurations, and alternative interlocking mechanisms like helical gaps or tabs and apertures to prevent interlocking, ensuring secure engagement and easy separation during handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If tolerance rings are designed with a gap configuration to allow radial expansion and contraction, then the tolerance ring can accommodate manufacturing variations and thermal expansion, but the gap causes tolerance rings to interlock during shipping and handling
Solution Approach 1:
The gap is configured in a non-linear, asymmetric pattern around the circumference rather than as straight radial gaps. This asymmetric gap configuration prevents tolerance rings from interlocking during shipping and handling while still allowing necessary radial expansion and contraction movements.
Solution Approach 2:
The gap configuration uses curved, non-linear paths instead of straight lines. This curvature prevents the interlocking mechanism that would occur with linear gaps, as the curved gap edges cannot properly engage with corresponding features on adjacent rings during shipping.
2Strength
If tolerance rings include contacting portions that are compressed during installation, then radial preload and frictional engagement are created to prevent slippage, but the compression makes separation labor-intensive and time-consuming
Solution Approach 1:
The tolerance ring is segmented into multiple sections or zones with varying compression characteristics. This segmentation allows the ring to maintain strong frictional engagement where needed while having sections that facilitate easier separation during handling operations.
Solution Approach 2:
The contacting portions are designed with dynamic compression characteristics that allow for controlled engagement and separation. The compression force can be dynamically adjusted or released during separation operations, reducing the labor and time required while maintaining engagement strength during operation.
3Measurement precision
If the actuator arm interface requires high rigidity and strength to prevent slippage during shock events, then precise head position control is achieved, but the interface becomes more susceptible to catastrophic failure during extreme shock events
Solution Approach 1:
The tolerance ring interface incorporates pre-designed compliance elements or cushioning features that activate during extreme shock events. These elements provide beforehand cushioning that prevents catastrophic failure by allowing controlled deformation or energy absorption when shock forces exceed normal operating limits.
Solution Approach 2:
The interface design allows for parameter changes in material properties or structural characteristics under different loading conditions. The tolerance ring can transition from a rigid engagement mode during normal operation to a more compliant mode during shock events, preventing catastrophic failure while maintaining precision under normal conditions.
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
Prevents tangling and interlocking of tolerance rings during shipping and handling, reducing handling damage and labor costs while maintaining effective radial preload and frictional engagement for precise actuator arm positioning.
Implementation Method 1
The contacting portions are typically partially compressed during installation to create a radial preload between the mating cylindrical features of the parts joined by the tolerance ring
Implementation Method 2
The radial preload compression provides frictional engagement that prevents actual slippage of the mating parts
Data Source
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AI summary
A tolerance ring configured to prevent interlocking during shipping and handling. The tolerance ring has a cylinder with a first radius about an axis of rotation and a gap in the cylinder surface having a first edge and second edge extending along the axis. The gap in the cylindrical base has a first tab on the first edge and a second tab on the second edge. The first tab is adapted for coupling to the second tab and thereby prevents the interlocking of one tolerance ring with another. The gap can be configured to be non-linear.