Actuator Arm Thinned Overlap Regions for Hard Disk Shock Resistance

Solution Overview

Problem

In disk devices, such as hard disk drives, the reduced clearances between magnetic disks and actuator arms lead to increased mechanical stress, causing potential contact and damage to data recording regions, especially during external shocks or vibrations, which affects data integrity and device reliability.

Innovation Solution

The design incorporates arms with overlapping regions that have thinned portions to prevent contact with the data recording regions, featuring stepped or tapered cut-off portions at the edges, allowing for reduced thickness in specific areas to mitigate mechanical stress and improve shock resistance without extending the arms or separating the actuator from the disks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of magnetic disks and actuator arms is increased to increase storage capacity, then the storage capacity is improved, but the clearances between components are reduced and mechanical stress increases

Engineering Contradiction:

Improvestorage capacityVSAvoidcomponent clearance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The arm is designed with a local quality change: a thinned portion is created at the specific location where the arm overlaps with the data recording region of the magnetic disk. This local thinning reduces the arm's thickness only in the critical overlapping area, allowing the arm to be more flexible and less likely to contact the data recording region during vibrations or shocks, while maintaining the overall structural integrity and strength of the arm in other regions.

Inventive Principle:

Principle #3Local quality

2Device complexity

If the clearances between magnetic disks and arms are reduced to increase component density, then the device compactness is improved, but the shock resistance deteriorates

Engineering Contradiction:

Improvecomponent densityVSAvoidshock resistance

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The invention applies parameter changes by modifying the thickness parameter of the arm in the overlapping region. By reducing the thickness of the arm at this specific location, the arm becomes more compliant and better able to absorb mechanical shocks and vibrations without contacting the magnetic disk's data recording region, thereby improving shock resistance while maintaining compact component spacing.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If the arm thickness is reduced in overlapping regions, then the shock resistance is improved, but the arm strength may be compromised

Engineering Contradiction:

Improveshock resistanceVSAvoidarm strength

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The arm is designed with a local quality change: a thinned portion is created at the specific location where the arm overlaps with the data recording region of the magnetic disk. This local thinning reduces the arm's thickness only in the critical overlapping area, allowing the arm to be more flexible and less likely to contact the data recording region during vibrations or shocks, while maintaining the overall structural integrity and strength of the arm in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The arm is segmented into regions with different thicknesses: a thinned portion in the overlapping region and a thicker portion in non-overlapping regions. This segmentation allows each region to serve its specific function - the thinned region provides flexibility and shock absorption, while the thicker regions maintain structural strength and support the actuator head.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11217275B2Disk device having head-support arms with reduced thickness regions that overlie disk regions when in a parked state

Publication Date: 2022.01.04 KK TOSHIBA

AI summary

A disk device includes a magnetic disk having a data non-recording region, and a data recording region inside the data non-recording region, a plurality of heads configured to read and write information from and onto the magnetic disk, and a plurality of arms supporting the heads, the arms being rotatable to move the heads from a parked position to a desired data recording position above or below the magnetic disk. Each of the arms comprises an overlapping region that overlaps the data recording region of the magnetic disk in a thickness direction of the magnetic disk when the heads are at the parked position.