Blower Impeller Shroud Integration for Thrust Management

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Solution Overview

Problem

Conventional blowers face challenges in reducing size while maintaining high pressure and flow rate, leading to increased thrust load on bearings, which reduces their lifetime and requires additional parts for performance separation.

Innovation Solution

The blower design integrates the impeller-side shroud with the impeller, eliminating the need for a separate shroud and reducing the number of parts, while adjusting the thrust direction by controlling the protrusion of the impeller-side shroud to maintain output performance and extend bearing life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the impeller diameter is reduced to reduce blower size, then the blower size is reduced, but the motor diameter increases leading to increased thrust load on bearings

Engineering Contradiction:
Improveblower sizeVSAvoidthrust load on bearing
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The shroud is divided into two separate functional parts: a housing-side shroud integrated into the blower housing and an impeller-side shroud integrated into the impeller. This segmentation allows independent optimization of each component, enabling the impeller diameter to be reduced for compactness while the housing-side shroud manages the thrust load distribution, thus resolving the contradiction between size reduction and thrust load management.

Inventive Principle:
Principle #1Segmentation

2Productivity

If a separate shroud is added to maintain output performance, then output performance is maintained, but the number of parts increases leading to increased assembly complexity

Engineering Contradiction:
Improveoutput performanceVSAvoidnumber of parts
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The housing-side shroud is merged with the blower housing as an integrated structure, and the impeller-side shroud is merged with the impeller as an integrated structure. This merging eliminates the need for separate assembled shroud components, reducing the number of parts and assembly steps while maintaining the shroud's essential function of guiding airflow and preserving output performance.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the impeller rotates at higher speed to maintain high pressure and flow rate, then pressure and flow rate are improved, but thrust load on bearing increases reducing bearing lifetime

Engineering Contradiction:
Improvepressure and flow rateVSAvoidbearing lifetime
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The shroud structure is designed with specific local geometric features including curvature radius ratios (R1/R2 between 0.5-2.0) and controlled gap dimensions (0.5-5mm) between the impeller-side shroud and housing-side shroud. These localized geometric optimizations improve airflow efficiency and pressure generation, allowing the impeller to operate at lower speeds for the same performance, thereby reducing thrust load and extending bearing lifetime.

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 design maintains output performance, reduces the number of parts, and improves bearing durability by adjusting the thrust acting on the impeller, thereby extending the bearing's lifetime.

Implementation Method 1

an impeller (2) having a rotation axis extending in an axial direction, and a plurality of blades (2b) arranged radially outward from the rotation axis in a direction perpendicular to the rotation axis

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3489523B1blower
Publication Date: 2021.07.28 SHINANO KENSHI CO LTD
  • EP3489523B1 patent drawingFigure 1A~1
  • EP3489523B1 patent drawingFigure 2A~2B
  • EP3489523B1 patent drawingFigure 3A~3B

AI summary

There is provided a blower capable of maintaining output performance and adjusting a thrust acting in an axial direction of an impeller while reducing the number of parts. A flow path is formed in an intake port (3a) provided in a central part in the axial direction of the first housing (3) and a blowing passage (8a) connecting the intake port (3a) and the discharge port (8b) as top surface portions (3e1, 2c1) of a housing-side shroud (3e) connecting to the intake port (3a) and an impeller-side shroud (2c) formed in the impeller (2) which face the blowing passage (8a) are adjacent to each other in the radial direction.