Compact Stick-Slip Piezoelectric Motor with Adjustable Preload
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current piezoelectric stick-slip motors face limitations in adjustability of preload force, size, and stress distribution, leading to reduced performance and increased production costs due to complex designs and high precision requirements.
Innovation Solution
A compact piezoelectric motor design featuring a preload screw for adjustable preload force, a rigid coupler with tapered spring for efficient force displacement, and a flexible preload arm for reduced stress and misalignment tolerance, allowing for easy assembly and calibration without disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the friction legs are arranged around the friction track forming a clamp configuration, then high preload forces can be applied without stressing the motion devices, but the preload force cannot be adjusted and the travel is limited by the length of the rod
Solution Approach 1:
The patent introduces an adjustable preload mechanism that transforms the static clamp configuration into a dynamic system where the preload force can be modified. The adjustment mechanism allows the preload force to be changed without disassembling the motor, enabling the system to adapt to different operational requirements while maintaining the beneficial concentric configuration.
2Adaptability or versatility
If the piezoelectric element is attached to friction legs contacting the track on one side, then the motor is more versatile and can be tangentially attached to any track, but lower forces are generated and stresses are added to the bearings
Solution Approach 1:
The patent merges the advantages of both configurations by integrating the adjustable preload mechanism into a compact design that maintains the concentric arrangement while enabling versatile attachment. The coupling portion is designed to efficiently transmit forces while the adjustable preload ensures optimal force generation without excessive bearing stresses.
3Volume of moving object
If a compact motor design is implemented, then the size is reduced for the same force output, but the assembly and calibration become more complex
Solution Approach 1:
The patent divides the motor into distinct modular components including the piezoelectric element, coupling portion, friction leg, and adjustment mechanism. This segmentation allows each component to be manufactured and calibrated separately using standard techniques, then assembled together. The modular design simplifies the overall assembly process and enables field calibration without requiring complex procedures.
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 design enhances manufacturability, usability, and performance by reducing motor size while maintaining force output, simplifying assembly, and enabling field adjustments, thus extending the motor's lifespan and reducing production costs.
Implementation Method 1
A piezoelectric element is attached to either the friction 'legs' or 'track'. When a slow varying voltage is applied to the piezoelectric element, the respective friction element will move.
Implementation Method 2
By applying a constant high pressure between the legs and the track, the friction legs can 'stick' to the friction track... the friction elements will 'slip' relative to each other due to the inertia of the masses
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A motion control system that includes a base, a stage supported by the base and movable with respect to the base, and a motor coupled to the base and operable to move the stage. The motor includes a mounting base arranged to connect the motor to the base, a friction pad engageable with the stage, and a coupling portion including a first end connected to the mounting base and a second end. The friction pad is connected to the coupling portion between the first end and the second end. A piezoelectric element is disposed between the mounting base and the second end and is operable in response to an electrical signal to move the friction pad and the stage. A mounting screw is accessible from an exterior of the base and engages the coupling portion. The mounting screw is the sole attachment mechanism between the motor and the base.