Pump Plain Bearing Grooves for High-Speed Torque Reduction

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Solution Overview

Problem

High-speed rotation of impellers in pumps leads to increased sliding resistance against restrictors, resulting in higher rotation torque and reduced pump performance due to the lack of effective lubrication and dynamic pressure management in existing plain bearings.

Innovation Solution

The implementation of an annular plain bearing with lubrication grooves and dynamic pressure generating grooves on the end face, which communicate with both radial sides to supply fluid for lubrication and generate dynamic pressure, respectively, reducing sliding resistance by directing the dynamic pressure away from the restrictor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the impeller rotates at high speed, then the pump transfers more fluid by pressure, but the sliding resistance of the plain bearing against the restrictor increases, causing higher rotation torque and lower pump performance

Engineering Contradiction:
Improvefluid transfer rateVSAvoidsliding resistance
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The patent introduces fluid dynamics principles by creating grooves that generate dynamic pressure and supply lubrication fluid. The grooves utilize the fluid flow created by impeller rotation to generate dynamic pressure that acts on the end face of the plain bearing, and supply lubrication fluid to reduce sliding resistance between the plain bearing and restrictor.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical parameters of the bearing surface by forming grooves with specific dimensions and patterns. The grooves have controlled depth, width, and spacing to optimize fluid flow characteristics and dynamic pressure generation, thereby reducing sliding resistance at high rotation speeds.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If no lubrication is provided to the plain bearing, then the structure remains simple, but the sliding resistance increases at high rotation speeds

Engineering Contradiction:
Improvebearing structureVSAvoidsliding resistance
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The plain bearing structure utilizes the fluid flow already present in the pump system to provide its own lubrication. The grooves are designed to capture and utilize the fluid created by impeller rotation, eliminating the need for external lubrication systems while reducing sliding resistance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent employs hydraulic principles by using the pump fluid itself as the lubrication medium. The grooves are configured to supply lubrication fluid to the contact surface between the plain bearing and restrictor, utilizing the existing fluid system rather than requiring separate lubrication infrastructure.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 configuration minimizes the increase in rotation torque during high-speed impeller rotation, maintaining pump performance by reducing sliding resistance through effective lubrication and dynamic pressure management.

Implementation Method 1

a lubrication groove communicating with a radially inner side and a radially outer side of the end face to supply the fluid onto the end face for lubrication

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

a dynamic pressure generating groove that introduces a fluid flow created by rotation of the impeller to generate a dynamic pressure

Methodology Applied
Scientific EffectDynamic pressure: Pressure Increase

Data Source

PatentEP3239543B1Plain bearing and pump
Publication Date: 2022.10.05 EAGLE INDS
  • EP3239543B1 patent drawingFigure 1
  • EP3239543B1 patent drawingFigure 2
  • EP3239543B1 patent drawingFigure 3

AI summary

The present invention relates to a plain bearing (410) and a pump (100) that includes this plain bearing (410). The plain bearing (410) is fixed to a shaft hole (401) of an impeller (400) of the pump (100) so as to rotatably support the impeller (400) with respect to the shaft (300), and is restricted from moving in an axial direction by an annular restrictor (310) fixed to the shaft (300). On an end face (411) of the plain bearing (410) facing the restrictor (310), a lubrication groove (412) connecting a radially inner side and a radially outer side of the end face (411) to supply cooling water onto the end face (411) for lubrication, and a dynamic pressure generating groove (413) that introduces a flow of cooling water created by rotation of the impeller (400) to generate a dynamic pressure, are provided. The present invention thereby enables to suppress an increase in rotation torque of the impeller (400) during high speed rotation.