Vacuum Pump Housing Pressure Equalization

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Solution Overview

Problem

Conventional vacuum pumps in motor vehicles face high structural complexity and reduced efficiency due to the high load on bearing devices caused by pressure differences between the rotor and motor housings, leading to lubricant loss and leakage issues.

Innovation Solution

Incorporating passage openings in the housing wall directly between the bearing device and the housing wall to facilitate pressure equalization between the rotor and motor housings, using a roller bearing and a thrust washer for reliable and long-lasting operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the rotor housing and motor housing are hermetically sealed, then the volumetric efficiency of the vacuum pump is improved, but the bearing device is exposed to extremely high load due to pressure difference

Engineering Contradiction:
Improvevolumetric efficiencyVSAvoidbearing device load
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The housing wall is segmented by introducing passage openings that divide the pressure distribution around the bearing device. This allows the bearing to be exposed to averaged pressure rather than extreme pressure differences, reducing load while maintaining overall hermetic sealing for volumetric efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The passage openings act as intermediary channels that mediate the pressure difference between rotor and motor housings. By providing controlled pressure equalization paths, they reduce the extreme pressure load on the bearing device while preserving the hermetic seal necessary for vacuum pump efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a targeted leakage geometry is installed to reduce bearing load, then the pressure difference load on the bearing device is reduced, but the structural complexity is very high

Engineering Contradiction:
Improvebearing device loadVSAvoidhousing structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The passage openings are integrated directly into the housing wall structure, merging the pressure equalization function with the existing housing component. This eliminates the need for separate leakage geometry components, reducing structural complexity while maintaining bearing load reduction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing wall serves multiple functions: it provides structural support, maintains hermetic sealing, and incorporates passage openings for pressure equalization. This multi-functionality reduces the need for additional components, simplifying the overall structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If passage openings are provided in the housing wall, then pressure equalization is achieved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvepressure equalizationVSAvoidpassage opening precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The passage openings are positioned locally in specific regions of the housing wall where pressure equalization is most needed. By concentrating the pressure equalization function in specific local areas rather than requiring uniform precision throughout the entire housing, manufacturing complexity is reduced.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The passage openings are designed with optimized dimensions and positions that balance pressure equalization effectiveness with manufacturing feasibility. By carefully selecting parameters such as opening size, shape, and location, the design achieves reliable pressure equalization without requiring excessive manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

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 enhances the volumetric efficiency of the vacuum pump, reduces the load on the bearing device, and prevents lubricant loss, resulting in a more reliable and cost-effective solution.

Implementation Method 1

at least one passage opening which fluidly connects the rotor housing and the motor housing is provided in the housing wall, the at least one passage opening being provided directly in the region of the bearing device between the bearing device and the housing wall

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Data Source

PatentEP2729667B1Vacuum pump for use in the automotive sector
Publication Date: 2017.06.07 PIERBURG PUMP TECH
  • EP2729667B1 patent drawingFigure 1~2

AI summary

The invention relates to a vacuum pump for use in the automotive sector, comprising a rotor element (32) that is fixed on a rotor shaft (14) and arranged in a rotor housing (8), and an electric drive body (10) which directly or indirectly drives said rotor shaft and is arranged in a motor housing (6), said rotor housing (8) and motor housing (6) being interconnected by a housing wall (20) and forming a housing arrangement (4), the rotor shaft (14) being mounted in the housing wall (20) by means of a bearing device (34), said rotor housing (8) having at least one inlet and one outlet, and at least one passage opening (36) being provided, in said housing wall (20), which fluidically connects the rotor housing and the motor housing.