Radial Blower Shaft Seal Geometry for High-Pressure Leak Prevention

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Solution Overview

Problem

Radial blowers experience leaks due to shaft seal failures, particularly at higher pressures, posing security concerns.

Innovation Solution

A shaft seal design featuring a collar, groove section, angle section, and sealing lip, which provides a self-reinforcing sealing mechanism that enhances sealing performance under increasing pressure, ensuring a dynamic seal even at negative pressures, and is rotationally symmetrical for easy assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional shaft seal is used in radial blowers, then the structure is simple and easy to manufacture, but the sealing performance deteriorates at higher pressures leading to leaks

Engineering Contradiction:
Improvesealing performanceVSAvoidshaft seal structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The shaft seal is divided into distinct functional sections: a collar section for structural support, a groove section for shaft engagement, an angle section for pressure distribution, and a sealing lip section for the actual sealing contact. This segmentation allows each part to be optimized for its specific function, improving overall sealing performance at high pressures while maintaining manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing lip is designed to be flexible and deformable, allowing it to dynamically adapt to pressure changes. Under increasing pressure, the sealing lip deforms to maintain contact with the shaft, creating a self-reinforcing sealing effect. This dynamic behavior enables reliable sealing at both positive and negative pressures without requiring complex active control mechanisms.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the shaft seal is designed with a self-reinforcing mechanism for high pressure sealing, then sealing performance improves at higher pressures, but the structural complexity increases

Engineering Contradiction:
Improvesealing behavior at high pressureVSAvoidshaft seal geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The shaft seal utilizes the pressure differential itself to enhance sealing. The angle section is configured so that increasing pressure forces the sealing lip tighter against the shaft, creating a self-reinforcing effect. The structure automatically adjusts to pressure changes without external intervention, improving high-pressure sealing while avoiding complex control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The angle section introduces a geometric dimension that converts radial pressure into axial sealing force. By angling the sealing surface, the design exploits pressure in one dimension to create sealing contact in another dimension, achieving improved high-pressure sealing through geometric configuration rather than additional components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the sealing lip extends obliquely towards the axis of symmetry, then a dynamic sealing effect is achieved under increasing pressure, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvedynamic sealing effectVSAvoidsealing lip geometry
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The angle section is designed with specific geometric parameters that optimize the transition from radial to axial force. By carefully selecting the angle and dimensions of this section, the design achieves reliable dynamic sealing while keeping manufacturing tolerances within practical limits. The parameters are optimized to balance sealing performance with manufacturability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4095389B1Shaft seal for sealing a shaft opening
Publication Date: 2024.11.06 EBM PAPST LANDSHUT GMBH
  • EP4095389B1 patent drawingFigure 1~2

AI summary

Shaft seal for sealing a shaft penetration of a blower, in particular a shaft seal for sealing a shaft penetration of a radial blower, wherein the shaft seal has an axis of symmetry, wherein the shaft seal has a collar at a first end radially inward in the direction of the axis of symmetry, wherein the shaft seal comprises, starting from the collar and extending radially away from the axis of symmetry, a groove section, an angled section and a sealing lip.The shaft seal is characterized in that the sealing lip is connected to the angled section at a first end and is angled to the angled section, wherein, starting from the angled section, the sealing lip extends obliquely in a radial direction towards the axis of symmetry, wherein the sealing lip has a second end which is spaced apart from the angled section, wherein a first end of the collar and the second end of the sealing lip define a plane, wherein the angled section is on a bottom side of the plane and the groove section is on a top side of the plane.