Piezoelectric Three-Axis Adjustment Device Eliminates Friction
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Solution Overview
Problem
Conventional electromagnetic actuators used in high-precision attitude adjustment mechanisms suffer from large volume, electromagnetic leakage, high power consumption, heat generation, and mechanical friction issues, while friction hinge connections result in low transmission precision and device contamination.
Innovation Solution
A three-degrees-of-freedom angle adjustment device driven by piezoelectric ceramics, comprising Z-direction, X-direction, and Y-direction deflection mechanisms connected through flexure hinges, utilizing pre-compressed piezoelectric stack actuators and beams to achieve independent deflection in X, Y, and Z directions without mechanical friction, with a compact structure and low power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electromagnetic actuators with voice coil motor are used, then actuation capability is achieved, but device volume becomes large and power consumption increases with heat generation
Solution Approach 1:
The patent replaces electromagnetic actuators with piezoelectric stack actuators, substituting an electromagnetic-mechanical system with a purely mechanical piezoelectric system. This substitution eliminates the need for large electromagnetic coils and magnets, dramatically reducing device volume while maintaining actuation capability through the piezoelectric effect that generates mechanical displacement directly from electrical voltage.
Solution Approach 2:
The patent changes the actuation mechanism from electromagnetic field-based to piezoelectric crystal-based, fundamentally altering the physical parameter domain. Piezoelectric materials convert electrical energy directly to mechanical displacement through crystal lattice deformation, achieving high-force actuation in a compact form factor without the heat generation and power consumption issues of electromagnetic systems.
2Strength
If friction hinge connection method is used, then mechanical connection is achieved, but transmission precision decreases and device wear occurs
Solution Approach 1:
The patent replaces traditional friction-based hinge connections with flexure hinges that utilize elastic deformation of flexible beams. This substitution eliminates sliding friction and contact wear by using bending deformation to achieve rotational motion, thereby maintaining mechanical connection strength while dramatically improving transmission precision and eliminating device wear and lubrication contamination.
Solution Approach 2:
The patent employs flexible beams with specific cross-sectional geometries (such as I-beam or rectangular sections) that act as flexure hinges. These flexible elements provide the necessary rotational compliance through controlled elastic bending, replacing rigid friction-based hinges. The flexible beams maintain structural integrity while enabling precise angular displacement without contact friction or wear.
3Force
If pre-compressed piezoelectric stack actuators are used, then output force increases, but device complexity increases
Solution Approach 1:
The patent applies pre-compression force to the piezoelectric stack actuators during assembly, placing them in a pre-loaded state. This preliminary action ensures that the actuators operate in a regime where they can generate maximum output force in the desired direction. The pre-compression is achieved through the mechanical design of the mounting structure that applies a constant compressive load to the piezoelectric stacks before operation.
Solution Approach 2:
The patent integrates the pre-compression mechanism into the overall structural design, merging the force application function with the mechanical support structure. Rather than adding separate complex pre-compression devices, the design combines the mounting substrate, support beams, and piezoelectric actuators into an integrated assembly where the structural elements themselves provide the necessary pre-compression force.
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
The device achieves high-precision, three-axis independent adjustment with no mechanical friction, large angular displacement output, and reduced power consumption, enhancing the practicality and performance in applications like aerospace engineering.
Implementation Method 1
applying a pair of differential voltages to a first X-direction piezoelectric stack and a second X-direction piezoelectric stack mounted in the X-direction deflection mechanism for generating a pair of differential displacement outputs based on the inverse piezoelectric effect
Implementation Method 2
Elastic deformation based on flexure hinge-based transmission structure has high transmission precision, no friction and no lubrication
Data Source
AI summary
A three-degrees-of-freedom adjustment device driven by piezoelectric ceramics includes a Z-direction deflection mechanism at a bottom, an X-direction deflection mechanism mounted at the bottom, a Y-direction deflection mechanism mounted on the X-direction deflection mechanism, and a stage mounted on a deflect block of a deflection mechanism angle output; wherein the Z-direction deflection mechanism is located at the bottom, including a mounting substrate and two pre-compressed piezoelectric stacks; the piezoelectric stacks in the Z-direction deflection mechanism deflect in a Z direction under equal voltages; the X-direction deflection mechanism is similar to the Y-direction deflection mechanism in principle, including a deflection mechanism frame and a pair of piezoelectric stacks, wherein the X-direction deflection mechanism and the Y-direction deflection mechanism are vertically mounted, and are perpendicular to the Z-direction deflection mechanism plane as a whole.