Gas-Bearing Spindle O-Ring Layout for Vibration Damping

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Solution Overview

Problem

Spindle devices with high-strength O-rings for vibration damping face reduced rotating speed due to whirling of the rotating shaft, as the O-ring position relative to the radial bearing is not optimally aligned with the housing center, leading to inadequate vibration damping.

Innovation Solution

A spindle device design featuring a rotating shaft with turbine blades, a radial bearing, a thrust bearing, and strategically placed O-rings between the housing and case, where the O-rings are positioned closer to the rotating shaft's center of gravity and the thrust bearing's rear end, enhancing vibration damping by distributing loads and reducing unbalanced vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the O-ring is positioned at the axial center of the housing to absorb vibration, then the vibration damping effect is improved, but the rotating shaft whirling increases and rotating speed decreases

Engineering Contradiction:
Improvevibration damping effectVSAvoidrotating speed
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent applies local quality by positioning the O-ring at a specific location between the radial bearing and the center of gravity of the rotating shaft, rather than uniformly at the housing center. This localized positioning creates optimal vibration damping at the critical area where the shaft swings greatly, while maintaining proper clearance and non-contact support at the bearing locations, thus preventing shaft whirling and speed reduction.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a high-strength material is used for the O-ring to increase deformation, then the vibration damping effect is improved, but the shaft whirling becomes larger and rotating speed decreases

Engineering Contradiction:
Improvevibration damping effectVSAvoidrotating speed
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent applies parameter changes by optimizing the material properties and dimensional parameters of the O-ring. Specifically, the O-ring is designed with appropriate hardness, cross-sectional diameter, and wire diameter ratios that allow sufficient elastic deformation for vibration damping while maintaining structural integrity and preventing excessive shaft whirling. The parameters are carefully selected to balance damping performance with rotational stability.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the O-ring position is defined from the axial center of the housing, then the structure is simple, but the vibration damping effect is insufficient due to inadequate alignment with the radial bearing

Engineering Contradiction:
Improvestructural simplicityVSAvoidvibration damping effect
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from a simple housing-center reference to a more precise positioning system that considers the actual vibration dynamics. The O-ring position is defined by specific distances from the radial bearing center and thrust bearing rear end, creating local quality optimization at the critical vibration zone while maintaining reasonable structural simplicity through standardized measurement references.

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

The enhanced O-ring placement and configuration significantly improve the vibration damping effect, allowing for stable rotation of the shaft even under large vibrations by effectively absorbing and distributing vibration forces.

Implementation Method 1

a radial bearing which is attached to the housing and floatingly supports the rotating shaft in a non-contact manner with respect to the housing by supplying gas

Methodology Applied
Scientific EffectGas bearing: Air Lubrication

Implementation Method 2

a thrust bearing which is attached to the housing and supports the rotating shaft in a thrust direction with respect to the housing by supplying gas

Methodology Applied
Scientific EffectGas bearing: Air Lubrication

Implementation Method 3

a plurality of O-rings which are arranged between the housing and the case and supports the housing with respect to the case

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 4

at least one O-ring is arranged between a center of the radial bearing and the center of gravity of the rotating shaft in an axial direction of the rotating shaft

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 5

the spindle device rotationally drives the rotating shaft by ejecting gas to the plurality of turbine blades

Methodology Applied
Scientific EffectImpulse turbine: Turbine

Data Source

PatentEP3754213B1Spindle device
Publication Date: 2022.03.30 NSK LTD
  • EP3754213B1 patent drawingFigure 1
  • EP3754213B1 patent drawingFigure 2

AI summary

Provided is a spindle device with which it is possible to increase the vibration damping effect and rotate a rotary spindle in a stable manner. The distance from the rear end surface of a thrust bearing to the center of gravity of the rotary spindle is greater than the diameter of the center of the surface area of the thrust bearing, and at least one O-ring is positioned between the center of the radial bearing and the center of gravity of the rotary spindle, in the axial direction of the rotary spindle.