Ultrasonic Motor Pressurization Unit for Stable Contact
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Solution Overview
Problem
Conventional ultrasonic motors face issues with maintaining an appropriate pressurized contact condition between the vibrator and the member to be driven due to manufacturing errors, deformation of components, and positional shifts, leading to potential contact failures.
Innovation Solution
The ultrasonic motor design incorporates a retention part with an abutting part shaped like a cylinder, where the center axis is parallel to the contact part and perpendicular to the driving direction, utilizing an elastic member to apply an impressing force, ensuring consistent line contact and maintaining the pressurized contact condition even with inclination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a plate spring with a convex part is used to impress the vibrator, then the vibrator can be pressed against the member to be driven, but manufacturing errors or deformation of the plate spring cause the contact part and the member to be driven to fail to come into appropriate pressurized contact
Solution Approach 1:
A pressurization member is introduced as an intermediary component between the plate spring and the vibrator. This mediator transfers the impressing force from the plate spring to the vibrator, ensuring that the force is applied accurately and consistently even when the plate spring deforms or has manufacturing errors. The pressurization member includes a pressurization surface that contacts the vibrator and transmits the force reliably.
Solution Approach 2:
The pressurization member is designed to automatically adjust and maintain appropriate pressurized contact between the vibrator and the member to be driven. The elastic member (plate spring) provides continuous impressing force that self-adjusts to compensate for manufacturing errors or deformation, ensuring the vibrator maintains proper contact without requiring external intervention or complex control mechanisms.
2Ease of manufacture
If the convex part for impressing is formed on the plate spring, then the vibrator can be impressed, but the convex part and the contact part of the vibrator are likely to be shifted with respect to each other due to errors or deformation
Solution Approach 1:
The pressurization member serves as a mediator that decouples the positioning requirements between the plate spring and the vibrator. The plate spring only needs to provide impressing force to the pressurization member, while the pressurization member handles the precise positioning and force transmission to the vibrator's contact part. This separation reduces the impact of manufacturing errors and deformation on the final positional relationship.
3Productivity
If the contact parts of the vibrators are arranged in the driving direction, then the member to be driven can be driven, but each vibrator is likely to be inclined perpendicular to the driving direction, causing partial contact
Solution Approach 1:
The pressurization member is designed with a curved pressurization surface that contacts the vibrator. This curvature allows the pressurization member to accommodate and correct inclination of the vibrator perpendicular to the driving direction. The curved surface ensures that the impressing force is distributed appropriately and maintains full contact between the vibrator and the member to be driven, even when the vibrator is inclined.
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 ensures a stable and appropriate pressurized contact condition between the vibrator and the member to be driven, preventing contact failures and maintaining efficient operation despite manufacturing errors or assembly inaccuracies.
Implementation Method 1
a piezoelectric element that is fixed on the vibrator, the vibrator being configured to drive the member to be driven by an ultrasonic vibration excited by the piezoelectric element
Implementation Method 2
a piezoelectric element that is fixed on the vibrator, the vibrator being configured to drive the member to be driven by an ultrasonic vibration excited by the piezoelectric element
Implementation Method 3
a pressurization unit including an elastic member so as to apply an impressing force on the at least one contact part against the member to be driven
Implementation Method 4
When an ultrasonic vibration is excited on the vibrator under the pressurized contact condition, an ellipsoidal motion is generated on the contact part of the vibrator, so that the member to be driven is driven to rotate about the rotation axis of the member to be driven
Data Source
AI summary
A driving motor includes a member having a contact surface, a vibrator including a contact part that is brought into contact with the contact surface, a pressing unit, and a contact member located between the pressing unit and the vibrator. The vibrator and the member move relatively by a vibration of the vibrator. The pressing unit comprises an elastic member so as to apply a pressing force on the contact part against the member including the contact surface. The contact member has a curved surface portion formed as an arc shape curved toward the pressing unit, and comes into contact with the pressing unit at the curved surface portion. The curved surface portion is formed so as to locate a position of a center of a circle including the arc shape of the curved surface portion not closer to the contact member than to the contact part.