Pump Plain Bearing Grooves for High-Speed Torque Reduction

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Solution Overview

Problem

Pumps with high-speed rotating impellers experience increased rotation torque due to sliding resistance between the plain bearing and restrictor, which affects performance.

Innovation Solution

Incorporating lubrication grooves and dynamic pressure generating grooves in the plain bearing to reduce sliding resistance by providing lubrication and generating a dynamic pressure that counteracts the sliding force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the impeller rotates at high speed, then the pumping performance increases, but the sliding resistance of the plain bearing against the restrictor increases, causing rotation torque to increase

Engineering Contradiction:
Improverotation speed of impellerVSAvoidsliding resistance of plain bearing
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The invention changes the physical state of the bearing surface by forming grooves that alter fluid distribution and pressure characteristics. The grooves modify the lubrication parameters (fluid film thickness, pressure distribution) to reduce sliding resistance while maintaining high-speed operation capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses fluid dynamics principles by creating grooves that generate hydrodynamic pressure and improve lubrication. The grooves facilitate fluid flow patterns that reduce friction between the plain bearing and restrictor, applying hydraulic/lubrication effects to mitigate sliding resistance

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of operation

If the plain bearing is fixed to the impeller, then the impeller can rotate with respect to the shaft, but the plain bearing moves along the axial direction, requiring a restrictor that increases sliding resistance

Engineering Contradiction:
Improverotational support of impellerVSAvoidsliding resistance between plain bearing and restrictor
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The groove configuration changes the lubrication parameters at the bearing-restrictor interface, modifying fluid film characteristics to reduce sliding resistance while maintaining the necessary axial positioning function of the restrictor

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The lubrication grooves act as an intermediary mechanism that introduces fluid between the plain bearing and restrictor surfaces. This fluid intermediary reduces direct solid-to-solid contact and sliding resistance, allowing the restrictor to perform its axial positioning function with reduced friction

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

Minimizes the increase in rotation torque of the impeller during high-speed rotation, thereby maintaining pump performance.

Implementation Method 1

a lubrication groove provides lubrication on the end face of the plain bearing, so that the sliding resistance of the plain bearing against the restrictor is reduced

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

The dynamic pressure generated by a dynamic pressure generating groove acts on the end face of the plain bearing in a direction away from the restrictor, so that the sliding resistance of the plain bearing against the restrictor is further reduced

Methodology Applied
Scientific EffectDynamic pressure: Pressure Gradient

Data Source

PatentEP3929455B1Plain bearing and pump
Publication Date: 2026.01.28 EAGLE INDS
  • EP3929455B1 patent drawingFigure 1
  • EP3929455B1 patent drawingFigure 2
  • EP3929455B1 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.