Vibration Actuator Antinode Contact Biasing

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Solution Overview

Problem

Existing vibration actuators using ultrasonic motors face issues with precision-dependent clearance settings, which can be disrupted by dust or manufacturing variations, and rely on expensive, difficult-to-process materials like ceramic for abrasion resistance, limiting their use and efficiency.

Innovation Solution

A vibration actuator design featuring an elastic body, an electromechanical transducer, and a rotating body that contacts the elastic body at a vibrational antinode, with a biasing member and position setting components to ensure efficient vibration transfer and reduce friction, allowing for the use of various materials and improved operational reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If clearance settings depend on precision of component dimensions, then manufacturing precision is improved, but reliability deteriorates due to sensitivity to dust and manufacturing variations

Engineering Contradiction:

Improveclearance setting precisionVSAvoidvibration transfer reliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

A biasing member (spring) is introduced as an intermediary element between the rotating body and the vibrating body. This spring maintains consistent contact pressure and ensures reliable vibration transfer while accommodating manufacturing tolerances and environmental variations, eliminating the need for precision clearance settings.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If ceramic material is used for abrasion resistance, then durability is improved, but cost and manufacturing difficulty increase

Engineering Contradiction:

Improveabrasion resistanceVSAvoidmaterial processing ease

Core Design Contradiction:

Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

Instead of using expensive ceramic material throughout the entire rotating body, the invention applies a hard coating only on the specific contact surface that experiences wear. This localized approach provides the necessary abrasion resistance while keeping the bulk material as inexpensive, easily processable metal.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The rotating body combines a metal base material with a hard coating layer, creating a composite structure that leverages the advantages of both materials: the metal provides ease of manufacturing and structural integrity, while the coating provides abrasion resistance.

Inventive Principle:

Principle #40Composite materials

3Power

If contact position is not at vibrational antinode, then device complexity is reduced, but power transfer efficiency deteriorates

Engineering Contradiction:

Improvevibration transfer efficiencyVSAvoidcontact position control

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The biasing member (spring) automatically positions the rotating body to contact the vibrating body at the vibrational antinode through its elastic deformation. The spring's natural elasticity causes it to deflect and apply contact force precisely where the vibration amplitude is maximum, eliminating the need for complex positioning mechanisms.

Inventive Principle:

Principle #25Self-service

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 solution enhances the reliability and cost-effectiveness of vibration actuators by maintaining efficient vibration transfer and reducing wear, enabling broader applications while minimizing the need for expensive materials.

Implementation Method 1

an electromechanical transducer that causes the elastic body to vibrate

Methodology Applied

Scientific EffectElectromechanical transduction: Piezoelectric Effect

Implementation Method 2

a rotating body that rotates in response to a drive force received from contact with the elastic body at a vibrational antinode

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8344591B2Vibration actuator and imaging device

Publication Date: 2013.01.01 NIKON CORP

AI summary

Provided is a vibration actuator comprising an elastic body; an electromechanical transducer that causes the elastic body to vibrate; and a rotating body that rotates in response to a drive force received from contact with the elastic body at a vibrational antinode thereof, wherein the rotating body contacts the elastic body at a prescribed position along a direction in which an axis of the rotation extends. In the vibration actuator, the elastic body includes an elastic body contact member that is arranged in a region that includes the vibrational antinode of the elastic body, the rotating body includes a rotating body contact member that receives a drive force by contacting the elastic body contact member, and one of the elastic body contact member and the rotating body contact member has a contact surface that is oriented diagonally to the axis of rotation and contacts the other of the elastic body contact member and the rotating body contact member.