Diaphragm Pump Bearing Structure for Shaft Hole Wear Resistance

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Solution Overview

Problem

Conventional diaphragm pumps face challenges with coaxial adjustment of the driving body's shaft hole and bearing member, which is time-consuming, and have low wear resistance of the shaft hole due to nonuniform sink marks during molding.

Innovation Solution

The diaphragm pump design incorporates a bearing member composed of a first and second bearing member superimposed on each other, with a shaft hole that includes a through hole in the first bearing member and a non-through hole in the second, forming an oil reservoir at their boundary to improve lubrication and wear resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If coaxial adjustment is performed on the mold for forming the driving body to align the shaft hole and bearing member, then the positioning precision is improved, but the adjustment time and complexity increase

Engineering Contradiction:
Improvecoaxial alignment precisionVSAvoidadjustment time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The bearing member is divided into a first bearing member and a second bearing member that are superimposed on each other. The shaft hole is formed as a through hole in the first bearing member and a non-through hole in the second bearing member. This segmentation allows the shaft hole to be formed independently of the driving body, eliminating the need for coaxial adjustment between the shaft hole and bearing member in the driving body mold.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shaft hole function is extracted from the driving body and transferred to the bearing member assembly. By forming the shaft hole in the bearing member (specifically in the first bearing member as a through hole), the requirement for coaxial adjustment between the driving body's shaft hole and bearing member is eliminated, simplifying the mold adjustment process.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If the shaft hole is formed in the driving body, then the structural integration is improved, but the wear resistance decreases due to nonuniform sink marks

Engineering Contradiction:
Improvestructural integrationVSAvoidwear resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The shaft hole function is extracted from the driving body and relocated to the bearing member. The shaft hole is now formed in the first bearing member (as a through hole) and second bearing member (as a non-through hole), separating the shaft hole formation process from the driving body molding process. This eliminates the sink mark issue in the driving body while maintaining structural functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The bearing member assembly acts as an intermediary component that provides the shaft hole function. By placing the shaft hole in the bearing member rather than the driving body, the design uses the bearing member as a mediator to resolve the conflict between structural integration and wear resistance, as the bearing member material and molding process are better suited for forming high-quality shaft holes.

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 simplifies the adjustment work on the mold for the driving body, enhances the circularity and wear resistance of the shaft holes, and ensures continuous lubrication, thereby improving the overall performance of the diaphragm pump.

Implementation Method 1

an oil reservoir that retains a lubricating oil in the bearing portion of the driving body

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4321755B1Diaphragm pump
Publication Date: 2025.05.14 MABUCHI MOTOR OKEN CO LTD
  • EP4321755B1 patent drawingFigure 1
  • EP4321755B1 patent drawingFigure 2
  • EP4321755B1 patent drawingFigure 3

AI summary

A diaphragm pump includes a driving mechanism including a crank body fixed to the rotating shaft of a motor, a driving shaft that is fixed to the crank body and inclined, and a driving body rotatably supported by the driving shaft via a bearing member. The driving body includes a shaft portion that stores the bearing member, and an arm portion connected to the deformation portion of a diaphragm. The bearing member includes a first bearing member close to the crank body, a second bearing member spaced apart from the crank body, a shaft hole in which the driving shaft is rotatably fitted, and an oil reservoir formed at a boundary between the first and second bearing members. The shaft hole includes a through hole formed in the first bearing member, and a non-through hole formed in the second bearing member.