Loading-Protected Bending Microactuator for Disk Drive Suspension

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Solution Overview

Problem

Existing disk drive suspensions face challenges with the fragility of bending motors, complexity, and high costs, limiting their adoption, particularly in using single PZT bending motors for fine positioning without additional pivot structures and efficient electrical connections.

Innovation Solution

A microactuated disk drive suspension design featuring a cantilevered bending motor with an unsupported, laterally bendable region and a load assist structure to prevent undue loading, utilizing a single PZT with asymmetrically divided electrodes for differential response, and a common ground electrical connection to simplify and lower costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a bending motor with an unsupported bending region is used to achieve fine positioning, then positioning precision is improved, but the reliability deteriorates due to the fragility of the unsupported region

Engineering Contradiction:

Improvepositioning precisionVSAvoidreliability of bending motor

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The bending motor is divided into three distinct regions: a fixed support region, an unsupported bending region, and a transition region. This segmentation allows the bending region to be isolated and protected, enabling precise positioning while maintaining reliability by preventing stress concentration at critical interfaces.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A load assist structure is introduced to provide beforehand cushioning to the unsupported bending region. This structure prevents undue loading and stress concentration before they can cause damage, thereby protecting the fragile bending region while maintaining the precision positioning capability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If additional pivot structures are added to support the bending motor, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improvereliability of bending motorVSAvoidcomplexity of suspension structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The load assist structure is merged with the existing suspension components rather than being added as a separate pivot structure. This integration provides the necessary support and protection for the bending motor while avoiding the complexity of additional pivot mechanisms, achieving reliability without increasing device complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If multiple electrical connections are made to the PZT for differential polarized control, then positioning precision is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvepositioning precisionVSAvoidease of electrical connection

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple electrical connections to the PZT are merged into a single common ground connection. This simplification maintains the differential polarized control capability for precise positioning while significantly reducing manufacturing complexity and the difficulty of electrical connection.

Inventive Principle:

Principle #5Merging (Combining)

4Device complexity

If a single PZT is used instead of multiple PZTs, then device complexity is reduced, but the ability to prevent undue loading deteriorates

Engineering Contradiction:

Improvecomplexity of bending motorVSAvoidprotection from loading

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

A load assist structure is introduced as an intermediary element between the single PZT and the suspension components. This intermediary protects the PZT from undue loading while maintaining the simplicity of using a single PZT, thereby achieving reliability without increasing device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the reliability and cost-effectiveness of disk drive suspensions by enabling precise slider positioning without mechanical pivots, protecting the bending motor from loading, and simplifying electrical connections, while allowing for visual polarity determination and efficient voltage application for bending responses.

Implementation Method 1

a bending motor such as a differentially polarized single PZT

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS7459835B1Loading-protected bending microactuator in additive suspensions

Publication Date: 2008.12.02 MAGNECOMP CORP

AI summary

A microactuated disk drive suspension for supporting a slider at a disk includes a load beam extending in a plane and having on a common axis a base section adapted for mounting to an actuator, a spring section and a beam section carrying a flexure and the slider thereon. The suspension has relatively movable proximate and distal portions on the common axis that are joined by a bending system cantilevered from the proximate portion and including a cantilevered bending motor opposed to the common axis and having a laterally bendable unsupported region. A cantilevered laterally bendable load assist structure defined by the suspension edges is provided arranged to block undue loading of the bending motor unsupported region.