Pinwheel Electrode Piezo Actuator for Torsional Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary ultrasonic motors using piezoelectric materials have complex structures, making them difficult to commercialize due to low efficiency and challenging for mass production and miniaturization.
Innovation Solution
A piezoelectric actuator with a pinwheel wing-shaped electrode structure that operates in a torsional vibration mode, allowing for a simpler ultrasonic motor design by varying the lengths of electrode wings from a central point, and a ring-shaped rotor mounted on a side groove, facilitating manufacturing through powder pressing or injection molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional cylindrical piezoelectric actuator with divided electrodes is used to generate tangential vibration, then the rotor can be rotated, but the structure becomes complex and efficiency decreases
Solution Approach 1:
The electrode structure is segmented into pinwheel wing-shaped sections with varying lengths radiating from the center. This segmentation creates different vibration characteristics in different regions, enabling torsional vibration mode while maintaining a planar, simple overall structure that is easier to manufacture than conventional cylindrical actuators.
Solution Approach 2:
The electrode wings are designed with asymmetric length variations from the central point, creating an asymmetric electrode pattern. This asymmetry generates the necessary torsional vibration mode by creating unequal expansion forces in different angular positions, simplifying the actuator structure while maintaining rotational functionality.
2Productivity
If conventional ultrasonic motor designs are used, then rotation can be achieved, but mass production and miniaturization become difficult
Solution Approach 1:
The piezoelectric actuator body integrates multiple functions: it serves as both the vibrating element and the mounting structure for the rotor. The side groove is formed directly in the actuator body, eliminating the need for separate mounting components. This self-service design reduces part count and assembly steps, facilitating mass production and miniaturization.
Solution Approach 2:
The actuator body and rotor mounting structure are merged into a single integrated component. The side groove for rotor mounting is formed directly in the piezoelectric actuator body, combining what would traditionally be separate parts into one unified structure, thereby simplifying manufacturing and enabling mass production.
3Power
If high energy density is utilized in ultrasonic vibration, then high torque at low speed can be generated, but the complex structure reduces overall efficiency
Solution Approach 1:
The piezoelectric actuator utilizes ultrasonic mechanical vibration in torsional mode to generate high torque at low speeds. The pinwheel wing-shaped electrode structure with varying lengths optimizes the vibration distribution, enabling efficient energy conversion from electrical to mechanical energy while maintaining high torque output and improving overall energy efficiency.
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 pinwheel wing-shaped electrode structure enables a simpler and more efficient ultrasonic motor design, allowing for energy savings and easier mass production by generating torsional vibration, thus overcoming the complexity and efficiency issues of existing motors.
Implementation Method 1
A piezoelectric actuator for an ultrasonic motor includes: a plate-shaped body formed of a piezoelectric material; a first electrode having a pinwheel wing shape formed on one of upper and lower surfaces of the plate-shaped body and operable in a torsional vibration mode by varying lengths of the electrode wings from a central point of the piezoelectric actuator
Implementation Method 2
the ultrasonic motor has an advantage of generating high torque at low speed without generating EMI
Data Source
AI summary
The present invention relates to a piezo actuator having an electrode structure for a torsional vibration mode, and to a rotation-type ultrasonic motor containing the same. In the piezo actuator having the electrode structure, electrodes may have different lengths from the center point of the piezo actuator in order to form an electrode structure having a pinwheel shape for enabling a torsional vibration mode. Thus, since the electrodes of the piezo actuator for generating torsional vibrations has a simple pinwheel wing structure, a rotor coupled along a groove formed in the side surface of the piezo actuator may be rotated using the torsional directional vibrations due to the electrode structure.