Disc Drive Suspension Dimple Positioning for Flying Height Stability
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Solution Overview
Problem
The sensitivity of flying height to Z-height changes is high in conventional disc drive suspensions, especially with shorter load beams, making it difficult to maintain a stable flying height and reduce flying height dispersion due to mounting errors.
Innovation Solution
A suspension design with a dimple positioned shifted to the trailing side from the center of the slider, combined with a load beam and flexure structure that allows for elastic displacement, reduces Z-height sensitivity by altering the pitch moment and load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the load beam is shortened to reduce suspension length, then the suspension becomes more compact, but the flying height sensitivity to Z-height changes increases
Solution Approach 1:
The dimple is positioned asymmetrically on the slider, specifically shifted toward the trailing side from the longitudinal center. This asymmetric positioning creates a counterbalancing moment that compensates for the increased sensitivity to Z-height changes, thereby stabilizing the flying height despite the shortened load beam length.
Solution Approach 2:
The invention changes the positional parameter of the dimple from the conventional centered position to a shifted position toward the trailing side. This parameter change alters the moment arm and force distribution, reducing the flying height sensitivity to Z-height variations and enabling stable operation with shorter load beams.
2Device complexity
If the dimple is positioned at the center of the slider, then the structure is symmetric and simple, but the flying height dispersion due to mounting errors increases
Solution Approach 1:
The dimple is deliberately positioned asymmetrically toward the trailing side of the slider rather than at the center. This asymmetric positioning creates a compensating moment that reduces the sensitivity to mounting errors and Z-height variations, thereby improving flying height consistency across different manufactured units.
3Ease of operation
If the Z-height increases, then the deflection of the suspension is reduced, but the load on the slider decreases and flying height stability deteriorates
Solution Approach 1:
The asymmetric positioning of the dimple toward the trailing side creates a moment that counteracts the reduced load effect. When Z-height increases and deflection decreases, the asymmetric dimple position generates a compensating moment that maintains the load distribution and stabilizes the flying height.
Solution Approach 2:
The asymmetric dimple positioning acts as a counterbalancing mechanism. The shifted dimple creates a moment that counterweights the effect of reduced suspension deflection and load, thereby maintaining flying height stability across different Z-height 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
This design effectively reduces Z-height sensitivity, stabilizes flying height, and increases information integration density by minimizing flying height dispersion, even with shorter load beams.
Implementation Method 1
When the disc rotates, the slider is caused to fly slightly above a surface of the disc by the pressure of air that flows between the disc surface and the slider. Thereupon, an air bearing is formed between the disc and the slider.
Implementation Method 2
A load F produced by a spring force that corresponds to deflection of the suspension 1 acts on the flying slider 4 through the dimple 7.
Implementation Method 3
a load beam 2 and a flexure 23 attached to the load beam 20, and hinge members 24. The flexure 23 is disposed along the load beam 20 and fixed to the load beam. The flexure 23 extends in the longitudinal direction of the load beam 20.
Data Source
AI summary
A suspension for disc drive has a load beam, a flexure, and a slider. The slider is mounted on a tongue portion of the flexure. When a disc rotates, air flows from an air inflow end (leading side) toward an outflow end (trailing side), whereupon an air bearing is formed between the disc and the slider. A dimple is provided on the distal end portion of the load beam. The slider is supported by the dimple so as to be swingable in a pitch direction and a roll direction. The dimple is formed in a position shifted to the trailing side from the center of the slider. The shorter the length of the load beam, the greater the amount of the shift is.