Vibrating Motor Bearing Structure for Radial Position Accuracy

Solution Overview

Problem

Conventional vibrating motors face accuracy issues due to the direct radial alignment of magnets and coils, which can deteriorate vibration characteristics.

Innovation Solution

The design incorporates a stationary portion with a bearing portion having a tubular shape and two regions with different inner diameters, a coil, and a movable portion supported by an elastic portion, where the second region has a wider gap to improve coaxiality and vibration accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the magnet and coil directly face each other in radial direction with a gap, then the structure is simple, but the accuracy of radial position of movable portion is lowered

Engineering Contradiction:

Improvestructure simplicityVSAvoidradial position accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The bearing portion is divided into two distinct regions: a first region with a first gap and a second region with a second gap (wider than the first gap). This segmentation allows different gap sizes in different axial positions, improving radial position accuracy while maintaining structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bearing portion are given different local characteristics - the first region has a smaller gap for precise radial positioning, while the second region has a larger gap to reduce restoring force. This local differentiation resolves the contradiction between accuracy and simplicity.

Inventive Principle:

Principle #3Local quality

2Power

If the gap between magnet and coil is reduced to improve electromagnetic force, then the power increases, but the radial position accuracy is lowered

Engineering Contradiction:

Improveelectromagnetic forceVSAvoidradial position accuracy

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The bearing portion is divided into two distinct regions: a first region with a first gap and a second region with a second gap (wider than the first gap). This segmentation allows different gap sizes in different axial positions, improving radial position accuracy while maintaining structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bearing portion are given different local characteristics - the first region has a smaller gap for precise radial positioning, while the second region has a larger gap to reduce restoring force. This local differentiation resolves the contradiction between accuracy and simplicity.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If the restoring force of movable portion is reduced to improve vibration characteristics, then the vibration accuracy is improved, but the radial position stability is lowered

Engineering Contradiction:

Improvevibration accuracyVSAvoidradial position stability

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The bearing portion is divided into two distinct regions: a first region with a first gap and a second region with a second gap (wider than the first gap). This segmentation allows different gap sizes in different axial positions, improving radial position accuracy while maintaining structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bearing portion are given different local characteristics - the first region has a smaller gap for precise radial positioning, while the second region has a larger gap to reduce restoring force. This local differentiation resolves the contradiction between accuracy and simplicity.

Inventive Principle:

Principle #3Local quality

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 enhances the vibration characteristics and accuracy of the movable portion by maintaining appropriate gaps and reducing the restoring force, leading to improved radial position accuracy and simplified manufacturing.

Implementation Method 1

When the coil is energized to generate a magnetic field, the movable portion vibrates

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The top surface portion is above the movable portion and connected to the movable portion with an elastic portion interposed therebetween

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS11804765B2Vibrating motor and haptic device

Publication Date: 2023.10.31 NIDEC CORP(JP)

AI summary

A vibrating motor includes a stationary portion, and a movable portion able to vibrate with respect to the stationary portion along a center axis extending in a vertical direction. The stationary portion includes a bearing portion which supports the movable portion to be able to vibrate along the center axis and has a tubular shape extending along the center axis, a coil which directly opposes at least a portion of the movable portion in a radial direction, and a top surface portion which is above the movable portion and connected to the movable portion with an elastic portion therebetween. The bearing portion includes a first region which opposes the movable portion in the radial direction with a first gap therebetween, and a second region which is above the first region and opposes the movable portion in the radial direction with a second gap wider than the first gap therebetween.