Bearing Shield Deflection Element for Wet Rotor Pump Lubrication

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Solution Overview

Problem

Wet rotor motor pumps in household appliances face issues with air pockets forming in the rotor space and shaft bearing, leading to increased wear and the risk of overheating due to inadequate lubrication and cooling, especially when fluid levels are low.

Innovation Solution

A deflection element is integrated into the bearing plate or receptacle of the shaft bearing to divert fluid into a channel, ensuring lubrication and cooling of the shaft bearing, even with minimal fluid, and multiple channels are arranged around the shaft to enhance fluid flow and heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hollow channel in the shaft is designed to supply fluid to the shaft bearing, then the shaft bearing can be lubricated, but the manufacturing cost increases significantly

Engineering Contradiction:
Improveshaft bearing lubricationVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts the fluid supply function from the shaft's hollow channel structure and relocates it to a separate channel system in the end shield. This eliminates the need for complex hollow shaft manufacturing while maintaining bearing lubrication, thereby reducing manufacturing costs without compromising reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The fluid supply system is segmented into separate components: the end shield contains the fluid channels, while the shaft remains a simple solid structure. This segmentation allows the shaft to be manufactured simply without expensive hollow channel features, while the end shield handles the complex fluid distribution function.

Inventive Principle:
Principle #1Segmentation

2Reliability

If sufficient liquid flows into the rotor space to lubricate the shaft bearing, then the shaft bearing is prevented from running dry, but the likelihood of dirt particles entering the rotor space and causing blockages increases

Engineering Contradiction:
Improveshaft bearing lubricationVSAvoiddirt particle contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention introduces an intermediary channel system through the end shield that acts as a controlled interface between the rotor space and shaft bearing. This intermediary structure allows precise control of fluid flow paths, enabling lubrication while filtering out dirt particles through the channel geometry and positioning, thus preventing contamination while maintaining reliable lubrication.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the rotor space is partially filled with fluid, then the pump can operate with low fluid levels, but the shaft bearing may run dry due to insufficient fluid reaching the bearing

Engineering Contradiction:
Improvelow fluid level operationVSAvoidshaft bearing lubrication
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The end shield channels are pre-configured to intercept and redirect fluid before it would naturally drain away. The channel geometry and positioning are designed in advance to capture even small amounts of fluid in the rotor space and actively guide them to the shaft bearing, ensuring lubrication is maintained even when the rotor space is only partially filled with fluid.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If a deflection element is added to divert fluid into the channel, then the shaft bearing can be lubricated with minimal fluid, but the device complexity increases

Engineering Contradiction:
Improveshaft bearing lubricationVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The deflection element is merged with the end shield structure itself, forming an integrated component rather than a separate part. The channel system and deflection features are combined into a single molded or machined end shield assembly, which maintains bearing lubrication functionality while avoiding the complexity of additional separate components or assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

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 solution prevents the shaft bearing from running dry, reduces wear, and effectively cools the shaft, thereby extending the service life of the pump and ensuring reliable operation in household appliances.

Implementation Method 1

a deflection element (22) is integrally formed on the bearing plate (14) and/or on the receptacle (17) of the shaft bearing (16), which deflection element serves to deflect the fluid into the channel (201, 202, 203, 204)

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

If the rotor space is not completely but only partially filled with the fluid, the fluid rotating with the rotor is pressed outward against the rotor housing shell due to the centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

Furthermore, the shaft and / or the shaft bearing can be cooled by the fluid, so that overheating of the shaft or the shaft bearing is avoided

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 4

the shaft bearing and / or the shaft is lubricated by the fluid from the intermediate space, so that the shaft bearing is prevented from running dry

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2165085B1Pump for a household appliance
Publication Date: 2010.10.13 BOSCH SIEMENS HAUSGERATE GMBH
  • EP2165085B1 patent drawingFigure 1
  • EP2165085B1 patent drawingFigure 2~3
  • EP2165085B1 patent drawingFigure 4~5

AI summary

The invention relates to a bearing shield (14) for bearing a shaft (2), especially of a wet rotor motor (1), the bearing shield (14) having a seat (17) for a shaft bearing (16), especially for a sliding bearing, said seat surrounding the shaft bearing (16) on its outer peripheral surface. The bearing shield comprises a channel (20) leading to an interspace (19) defined between the shaft end (15) and the bearing shield (14) and/or between the shaft bearing (16) and the bearing shield (14), a fluid flowing through said channel (20). A deflection element (22) is arranged on the bearing shield (14) and/or on the seat (17) and deflects the fluid towards the channel (20, 201).