Piezoelectric Motor Standing Waves Nano-Elliptical Motion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional 2-D wave excited piezoelectric motors suffer from low efficiency due to linear motion direction mismatch and limited contact points, resulting in inefficient force transfer and energy dissipation during mechanical coupling.

Innovation Solution

A piezoelectric motor utilizing standing acoustic waves to generate nano-elliptical motion through the superposition of orthogonal standing waves, allowing for higher order mode excitation and multiple contact points, with a single excitation source driving both longitudinal and transverse vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional 2-D wave excited piezoelectric motors use a single contact point in the center of the resonator, then the structure is simple, but the force transfer efficiency is low and energy dissipation occurs during mechanical coupling

Engineering Contradiction:

Improveenergy dissipationVSAvoidcontact point configuration

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The invention divides the single contact point into multiple contact points distributed along the resonator surface. This segmentation allows force to be applied at multiple locations simultaneously, improving force transfer efficiency and reducing energy dissipation during mechanical coupling while maintaining reasonable structural complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention combines multiple contact points into a distributed contact system that works together to transfer force. By merging the function of multiple contact points along the resonator surface, the system achieves superior force transfer efficiency and reduced energy loss compared to a single contact point

Inventive Principle:

Principle #5Merging (Combining)

2Productivity

If conventional piezoelectric motors use linear motion direction, then the mechanism is simple, but the force application direction does not align with motion direction resulting in low efficiency

Engineering Contradiction:

Improvemotor efficiencyVSAvoidmotion trajectory control

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention introduces elliptical motion trajectories instead of linear motion by superimposing orthogonal standing waves. This curved/elliptical motion path allows the contact points to move in an elliptical pattern that aligns force application with the direction of motion, improving motor efficiency while managing the complexity through mathematical wave superposition

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Productivity

If conventional piezoelectric motors excite only fundamental modes, then the control is simple, but the number of contact points is limited reducing performance

Engineering Contradiction:

ImproveperformanceVSAvoidmode excitation control

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention dynamically excites multiple vibrational modes (fundamental and higher order modes) simultaneously through carefully controlled standing waves. This dynamic multi-mode excitation creates multiple contact points along the resonator surface, enhancing performance while managing control complexity through systematic wave generation

Inventive Principle:

Principle #15Dynamics

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 approach enhances efficiency by aligning force application with motion direction and enables a large number of contact points, improving the overall performance and design flexibility of piezoelectric actuators.

Implementation Method 1

a piezoelectric body having a first order natural resonance frequency (v1) for a first standing longitudinal wave in a direction of the second longitudinal axis, an even order natural resonance frequency (v2) for a second standing longitudinal wave in a direction of the first longitudinal axis

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

utilizing standing acoustic waves to generate nano-elliptical motion through the superposition of orthogonal standing waves

Methodology Applied

Scientific EffectWave superposition: Interference

Implementation Method 3

one or more contact elements disposed on at least one of the third and the fourth surfaces at one or more contact locations

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8710719B2Piezoelectric quasi-resonance linear motors based on acoustic standing waves with combined resonator

Publication Date: 2014.04.29 PIEZO MOTION CORP

AI summary

A piezoelectric device includes a piezoresonator body (3) having opposing first and second surfaces and opposing third and fourth surfaces. The device also includes at least one common electrode (8) disposed on the second surface (15) and electrodes (4a, 4b) disposed on the first surface (14) in pairs along a first longitudinal axis. The device further includes contact elements (5) disposed on the third (16) and the fourth (17) surfaces at contact locations along the first longitudinal axis and aligned between each pair of excitation electrodes. In the device, the piezoelectric body has a first order natural resonance frequency (v1) along a second longitudinal axis and an even order natural resonance frequency (v2) along the first longitudinal axis, where a percent difference between v1 and v2 is greater than 0% and less than or equal to 20%.