Piezoelectric Micro Actuator Strain Matching for Vibration Control
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Solution Overview
Problem
Micro actuator devices using piezoelectric elements between upper and lower support plates face issues with bending deformation, which links to torsional and bending modes, reducing the natural frequency of the head suspension and limiting the control band.
Innovation Solution
The configuration includes a first and second piezoelectric element interposed between support plates, with upper support plates generating strain equal to the lower support plates, minimizing bending deformation and reinforcing the piezoelectric elements' strength, and using a hinge-like structure to maintain the control band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the piezoelectric element is interposed between the upper and lower pair of support plates, then the piezoelectric element is protected, but bending deformation occurs which reduces the natural frequency of the head suspension
Solution Approach 1:
The patent modifies the strain distribution parameters by designing the upper support plate to generate strain equal to that of the lower support plate when tensile force acts on the lower support plate. This parameter adjustment eliminates bending deformation while maintaining the protective function of the support plates around the piezoelectric element.
2Speed
If the upper support plate generates strain larger than the lower support plate, then displacement of the head slider occurs, but bending deformation is linked to torsional and bending modes which reduces natural frequency
Solution Approach 1:
The patent changes the strain parameter relationship between upper and lower support plates from unequal to equal strain generation. This eliminates the bending moment that causes torsional and bending modes, thereby maintaining natural frequency while still enabling head slider displacement through the controlled tensile force mechanism.
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 configuration reduces vibrations in torsional and bending modes, ensuring a wider control band and protecting the fragile piezoelectric elements while maintaining their effectiveness.
Implementation Method 1
The micro actuator device using a pair of piezoelectric elements is widely known. In the micro actuator device, each piezoelectric element is interposed between an upper and lower pair of support plates.
Data Source
AI summary
According to one embodiment, a micro actuator device, includes: a first piezoelectric element superposed on a first lower support plate coupled to a fixed plate; a second piezoelectric element superposed on a second lower support plate in parallel with the first lower support plate coupled to the fixed plate; a first upper support plate interposing the first piezoelectric element between the first upper support plate and the first lower support plate, and generating strain equal to strain of the first lower support plate when a tensile force of the first piezoelectric element acts on the first lower support plate; and a second upper support plate interposing the second piezoelectric element between the second upper support plate and the second lower support plate, and generating strain equal to strain of the second lower support plate when a tensile force of the second piezoelectric element acts on the second lower support plate.