Vibration Wave Motor Output Coupling for Precise Stop Alignment
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Solution Overview
Problem
Existing vibration wave driving apparatuses face issues with positional deviation and reduced output due to design constraints, particularly in miniaturization, as they either suffer from positional inaccuracies in gap-based transmission mechanisms or apply excessive force in pressurization-based mechanisms.
Innovation Solution
A vibration wave driving apparatus with a linear-type vibration wave motor that includes a piezoelectric element, an elastic member, a pressurizing mechanism using springs and leveraged fulcrums, and an output transmission member held by a torsion spring, allowing precise movement and minimizing external force impact on the vibrator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a gap-based output transmission mechanism is used, then the device structure is simpler, but positional deviation occurs between the moving element and driven member, adversely affecting stop accuracy
Solution Approach 1:
A connecting portion with a protruding portion is introduced as an intermediary element between the moving element and the driven member (AF ring). This protruding portion fits into a recess portion of the driven member, creating a mechanical coupling that eliminates gaps while maintaining structural simplicity. The intermediary connecting portion absorbs positional deviations through its design, preventing direct transmission of misalignment errors to the driven member.
Solution Approach 2:
The output transmission mechanism employs a dynamic fitting connection where the protruding portion of the moving element engages with the recess portion of the driven member. This dynamic engagement allows for automatic alignment and compensation of positional deviations during operation, maintaining stop accuracy without requiring rigid fixed connections or complex adjustment mechanisms.
2Measurement precision
If press-fitting or screwing is used to fasten the output transmission mechanism, then stop accuracy is improved, but an extra force is applied to the vibration wave driving apparatus due to parallelism errors, reducing output and deteriorating durability
Solution Approach 1:
The connecting portion with the protruding portion serves as a mediator between the moving element and driven member. This intermediary design allows for accurate positioning and stopping without requiring press-fitting or screwing operations. The protruding-recess fitting mechanism inherently accommodates parallelism errors, preventing the transmission of excessive forces to the vibration wave driving apparatus while maintaining high stop accuracy.
Solution Approach 2:
The design incorporates a fitting connection structure that beforehand cushions against the effects of parallelism errors. By using a protruding portion that fits into a recess portion, the mechanism preemptively absorbs misalignment forces, preventing them from being transmitted as damaging extra forces to the vibration wave driving apparatus during operation.
3Measurement precision
If the V-shaped recess portion is pressed against the projection by torsion spring force, then stop accuracy is secured by eliminating gaps, but the apparatus cannot be miniaturized due to design constraints on pressurizing force application
Solution Approach 1:
The connecting portion is merged with the moving element as an integral structure, eliminating the need for separate pressurizing members or torsion springs. The protruding portion of the connecting portion directly engages with the recess portion of the driven member, combining the functions of connection and positioning in a single integrated component. This merging enables miniaturization while maintaining stop accuracy through the precise fitting connection.
Solution Approach 2:
The complex pressurizing mechanism with torsion springs and V-shaped recess portions is extracted and replaced by a simpler protruding-recess fitting connection. This extraction removes unnecessary components that would increase apparatus size, while the essential function of eliminating gaps and securing stop accuracy is maintained through the streamlined fitting connection between the moving element and driven member.
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 apparatus achieves precise driving and suppresses output degradation while enabling miniaturization by maintaining accurate positional alignment and reducing unnecessary force on the vibration wave driving apparatus.
Implementation Method 1
an electric-mechanical energy conversion element such as a piezoelectric element which converts electric energy into mechanical energy
Implementation Method 2
a driven member, which includes an output transmission member that holds the outputting member in a direction of the relative-moving with a predetermined spring force
Data Source
AI summary
Provided is a vibration wave driving apparatus comprising: a vibration actuator; and a driven member configured to be driven by the vibration actuator, wherein the vibration actuator includes: a vibrator having an electric-mechanical energy conversion element and an elastic member to which the electric-mechanical energy conversion element is fixed; a pressurizing member configured to pressurize the vibrator; a contacting member configured to pressurizing-contact with the vibrator by pressurizing the vibrator by the pressurizing member and move relative to the vibrator; an outputting member configured to output a driving force to the driven member, the driving force generated by the relative-moving of the contacting member to the vibrator, and wherein the driven member includes an output transmission member configured to hold the outputting member in a direction of the relative-moving with a predetermined spring force.