Vibration Wave Motor Holding Structure Local Quality Design
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Solution Overview
Problem
Conventional ultrasonic motors face issues with vibration inhibition due to an unspecified abutting range between the holding member and the vibrator, leading to malfunction when trying to generate desired elliptic motion.
Innovation Solution
A vibration wave motor design with a holding structure featuring a first and second abutting portion, where the displacement of the first abutting portion is smaller than the second, and the area of the first abutting portion is greater than the second, allowing for efficient elliptic motion generation without inhibiting the entire vibrator's vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the abutting range of the holding member and the holding portion of the vibrator is enlarged to surely hold the vibrator, then the holding reliability is improved, but the vibration of the vibrator is inhibited
Solution Approach 1:
The holding member is designed with two abutting portions having different areas: a first abutting portion with a larger area that abuts a first displacement portion with small vibration displacement, and a second abutting portion with a smaller area that abuts a second displacement portion with large vibration displacement. This local differentiation allows the larger area to provide reliable holding while the smaller area minimizes vibration inhibition at the critical vibration region.
2Object-generated harmful factors
If the abutting range is reduced to avoid vibration inhibition, then the vibration generation is improved, but the holding reliability deteriorates
Solution Approach 1:
The holding member concentrates the majority of the holding area (first abutting portion) on the first displacement portion where vibration displacement is minimal, while using a smaller second abutting portion at the second displacement portion. This local quality distribution ensures that reliable holding is achieved through the larger first abutting portion, while the reduced second abutting portion minimizes vibration inhibition.
3Force
If the area of the abutting portion at the vibration region is increased to improve holding, then the holding strength is improved, but the vibrational energy concentration deteriorates
Solution Approach 1:
The holding member strategically places the larger first abutting portion at the first displacement portion where vibrational energy concentration is already high but vibration displacement is small. The smaller second abutting portion is placed at the second displacement portion where vibration displacement is large. This local quality differentiation maintains holding strength through the larger first abutting portion while preserving vibrational energy concentration by minimizing the area at the critical second displacement portion.
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 prevents vibration inhibition, ensuring reliable operation by concentrating vibrational energy on displacement portions and maintaining the elliptic motion, thus enhancing the motor's performance and reducing the risk of malfunction.
Implementation Method 1
The vibrator included in the ultrasonic motor includes a piezoelectric element, and AC voltages of two different phases can be applied to the piezoelectric element. The voltages are applied to the piezoelectric element to excite an elliptic vibration wave in a projection and the like provided on a surface of the vibrator.
Implementation Method 2
The projection of the vibrator is brought into contact with a friction member by pressure to generate driving force, and the vibrator slides on the surface of the friction member at desired driving force.
Data Source
AI summary
Provided is a vibration wave motor including a holding structure that does not inhibit vibration of the entire vibrator. The vibration wave motor includes: a vibrator that generates an elliptic motion; a holding means that holds the vibrator; and a driven body driven by the vibrator, wherein the holding means includes a first abutting portion and a second abutting portion abutting the vibrator, the vibrator includes a first displacement portion at a part abutting the first abutting portion and includes a second displacement portion at a part abutting the second abutting portion, a displacement of the first displacement portion is smaller than a displacement of the second displacement portion, and an area of the first abutting portion of the holding means is greater than an area of the second abutting portion.