Vacuum Pump Outlet Channel Cross-Sectional Change

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Solution Overview

Problem

Existing electric motor vehicle vacuum pumps face issues with dirt particles entering the soundproofing chamber and being sucked back into the pump rotor chamber when switched off, due to insufficient sealing, which increases manufacturing costs and noise levels.

Innovation Solution

The outlet opening arrangement features a channel design with a sudden cross-sectional change, utilizing successive channel elements to create a self-contained outlet channel that prevents particle ingress, combined with noise-damping chambers for effective soundproofing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If labyrinthine sealing means are provided in the outlet opening to prevent particle backflow, then particle contamination is reduced, but manufacturing cost increases

Engineering Contradiction:
Improveparticle contamination preventionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the geometric parameters of the outlet channel by introducing a sudden cross-sectional change with a specific area ratio (A2/A1 ≥ 3). This parameter modification creates a flow dynamic barrier that prevents particle backflow without requiring complex labyrinthine structures, thereby reducing manufacturing cost while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If soundproofing measures are implemented in the vacuum pump, then noise level is reduced, but particle sealing effectiveness is compromised

Engineering Contradiction:
Improvenoise levelVSAvoidparticle sealing effectiveness
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The invention segments the outlet opening arrangement into distinct functional zones: a soundproofing chamber for noise reduction and an outlet channel with sudden cross-sectional change for particle sealing. This segmentation allows each zone to independently perform its function without compromising the other, enabling both noise reduction and effective particle sealing.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If simple outlet opening design is used, then manufacturing cost is reduced, but particle backflow prevention is insufficient

Engineering Contradiction:
Improvemanufacturing costVSAvoidparticle backflow prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention introduces an intermediary structure - the outlet channel with sudden cross-sectional change - that mediates between the simple outlet opening and the particle backflow prevention requirement. This intermediary element is relatively simple to manufacture yet effectively prevents particle backflow by creating adverse flow conditions in the channel.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 significantly reduces the risk of particle contamination and enhances noise protection, ensuring effective sealing and sound insulation while maintaining a cost-effective manufacturing process.

Implementation Method 1

When the pump is switched off, air from the environment flows through the outlet opening into the pump due to the internal pressure that still prevails in the pump rotor chamber

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

the outlet channel which is closed off from the drive motor and the pump unit and which, seen in the direction of the outlet opening, has at least one sudden change in cross section as a sealing means

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Implementation Method 3

a considerable soundproofing is ensured by the reflection properties of the channel arrangement

Methodology Applied
Scientific EffectAcoustic reflection: Reflection

Implementation Method 4

the noise-damping means have at least two noise-damping chambers connected in series

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP3669081B1Motor vehicle vacuum pump arrangement
Publication Date: 2023.06.07 PIERBURG PUMP TECH
  • EP3669081B1 patent drawingFigure 1
  • EP3669081B1 patent drawingFigure 2

AI summary

The invention relates to an electrical motor vehicle vacuum pump arrangement which comprises a housing compound (4) having an inlet opening arrangement (30) with an inlet opening (31) and having an outlet opening arrangement (32) with an outlet opening (32), and which has a pump assembly (8) and a drive motor (6), wherein the pump assembly (8) has a pump rotor housing (14) consisting of an inlet- and outlet-side end wall (16, 18) and a pump rotor housing part (20) arranged between same, which enclose a pump rotor chamber (35) in which a pump rotor (36) is provided, wherein the drive motor (6) has a motor rotor (12) and a motor stator, wherein at least one sound absorption means (50, 58, 60) is provided for noise reduction, wherein the outlet opening arrangement (32) is connected to a sound absorption means (50, 58, 60) and wherein sealing means (70) are provided in the connection to the pump rotor chamber (35), directed towards the outlet opening (33), wherein the outlet opening arrangement (32) has an outlet channel (68) that is closed relative to the drive motor (6) and the pump assembly (8), which outlet channel, when viewed in the direction of the outlet opening (33), has at least one sudden change (70) in cross-section as a sealing means with an A2/A1 of ≥3, wherein A2 describes the cross-sectional area of a sub-region (66) after the change (70) in cross-section and A1 describes the cross-sectional area of a sub-region (64) before the change (70) in cross-section.