Piezoelectric Vibrator Stack Layout for Compact Slider Drives
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Solution Overview
Problem
Existing piezoelectric drive devices face challenges in downsizing due to the configuration of the case holding the piezoelectric element and coil spring, which limits the miniaturization of ultrasonic motors.
Innovation Solution
A piezoelectric drive device configuration featuring two vibrators with piezoelectric elements and a fixing portion with through holes for pin or screw insertion, where the vibrators are stacked in a layered structure and the fixing portion is placed between them, allowing for efficient drive force transmission and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a case is provided to hold the piezoelectric element and coil spring within the ultrasonic motor, then the structural integrity and component protection are improved, but the device size increases and downsizing becomes difficult
Solution Approach 1:
The patent removes the case that previously enclosed the piezoelectric element and coil spring, extracting this protective function and replacing it with a different structural arrangement. The piezoelectric element is now directly mounted on the vibrator without being enclosed in a case, thereby eliminating the volume occupied by the case while maintaining structural integrity through alternative support mechanisms.
Solution Approach 2:
The patent reorganizes the spatial arrangement of components by placing the piezoelectric element and coil spring in different dimensional configurations. Instead of enclosing them vertically within a case, the components are arranged to utilize available space more efficiently, with the piezoelectric element mounted on the vibrator surface and the coil spring positioned to provide urging force without requiring enclosement, thus reducing the overall device volume.
2Volume of moving object
If the piezoelectric element is directly mounted on the vibrator without a case, then the device can be downsized, but the position adjustment and manufacturing precision may be affected
Solution Approach 1:
The patent introduces a mounting structure that serves as an intermediary between the piezoelectric element and the vibrator. This mounting structure provides precise positioning features and adjustment mechanisms that ensure accurate placement of the piezoelectric element on the vibrator surface, thereby maintaining manufacturing precision even without the enclosing case that previously provided structural support.
3Volume of moving object
If multiple components are arranged within a compact space, then downsizing is achieved, but the assembly complexity and manufacturing difficulty increase
Solution Approach 1:
The patent divides the compact assembly into distinct functional modules: the vibrator with mounted piezoelectric element, the coil spring providing urging force, and the fixing portion with through holes. This segmentation allows each component to be manufactured and positioned independently, simplifying the assembly process despite the compact overall size. The through holes in the fixing portion enable straightforward alignment and fixation of components during assembly.
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 enables downsizing of the piezoelectric drive device, facilitating easier position adjustment and manufacturing, while maintaining high drive efficiency and mechanical strength.
Implementation Method 1
two vibrators 2 each having a vibrating portion 21 with piezoelectric elements 2a to 2f
Implementation Method 2
transmitting portions 24 placed in the vibrating portions 21 and transmitting drive forces to a driven member 100
Data Source
AI summary
A piezoelectric drive device includes two vibrators having vibrating portions with piezoelectric elements and transmitting portions placed in the vibrating portions and transmitting drive forces to a driven member (e.g. a slider), and a fixing portion having through holes (first through hole, second through hole) into which pins or screws are inserted. The two vibrators are placed adjoiningly along a drive direction of the slider, and the fixing portion is placed between the two vibrators and fixing the two vibrators.