Floating-Bearing Gear Pump Pressure Feedback for Leak Control

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Solution Overview

Problem

Gear pumps with floating bearings face instability and efficiency reduction at higher rotational speeds due to improper pressurization, leading to fluid leakage and increased resistance, which can cause unintentional failure.

Innovation Solution

A gear pump design with a floating bearing that incorporates a sealing face and communication path to create a negative feedback mechanism, maintaining proper pressurization by balancing pressure fluctuations through a medium pressure variate, thereby stabilizing the bearing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If rotational speed of gears is increased to improve efficiency, then productivity increases, but floating bearing becomes unstable leading to fluid leakage and efficiency reduction

Engineering Contradiction:
ImproveefficiencyVSAvoidfloating bearing stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces a feedback mechanism where pressure fluctuations in the first pressurization chamber (caused by gear rotation) are transmitted through a communication path to the third pressurization chamber, which applies compensating pressure to the floating bearing. This negative feedback stabilizes the bearing by counteracting pressure variations that occur at higher rotational speeds, allowing the pump to maintain both high productivity and bearing stability.

Inventive Principle:
Principle #23Feedback

2Reliability

If pressurization on bearing is increased to prevent fluid leakage, then sealing performance improves, but resistance to rotation increases causing heat generation and potential failure

Engineering Contradiction:
Improvesealing performanceVSAvoidheat generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent employs dynamic pressurization where the pressure applied to the floating bearing is not constant but varies dynamically with the rotational position of the gears. The communication path between pressurization chambers creates a dynamic pressure balance that adapts to the instantaneous operating conditions, providing sufficient sealing pressure only when needed while minimizing friction and heat generation during other phases of rotation.

Inventive Principle:
Principle #15Dynamics

3Productivity

If pressurization on bearing is decreased to reduce resistance, then heat generation reduces, but fluid leakage increases reducing pump efficiency

Engineering Contradiction:
Improvepump efficiencyVSAvoidheat generation
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The feedback mechanism through the communication path between pressurization chambers automatically adjusts the pressure on the floating bearing based on real-time operating conditions. When rotational speed increases or load changes, the system dynamically compensates to maintain optimal sealing pressure, preventing both excessive leakage and unnecessary friction-induced heat generation, thus optimizing the balance between efficiency and energy loss.

Inventive Principle:
Principle #23Feedback

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

The design maintains stable pressurization on the floating bearing, preventing fluid leakage and reducing resistance, ensuring efficient operation even at increased rotational speeds.

Implementation Method 1

a communication path having an opening on the sealing face and communicating the opening with the third pressurization chamber

Methodology Applied
Scientific EffectPressure fluctuation transmission: Pressure Gradient

Implementation Method 2

As pressure on the sealing face extracted through the communication path contains a pressure variate of an opposite phase relative to fluctuation of pressurization applied to the bearing and acts as negative feedback to the third receiver face

Methodology Applied
Scientific EffectNegative feedback: Feedback

Data Source

PatentEP4039979B1Gear pump
Publication Date: 2025.12.17 IHI CORP
  • EP4039979B1 patent drawingFigure 1
  • EP4039979B1 patent drawingFigure 2
  • EP4039979B1 patent drawingFigure 3

AI summary

A gear pump for pressurizing and expelling fluid is provided with: a casing including a suction port configured to suck the fluid, and a discharge port configured to expel the pressurized fluid; a gear including a wheel portion rimmed by gear teeth and a shaft portion axially elongated from the wheel portion, the gear being so housed in the casing that the gear teeth, by rotation of the gear about an axis, transport the fluid from the suction port to the discharge port; and a floating bearing rotatably supporting the shaft portion and being movable axially, the floating bearing including a sealing face in contact with the wheel portion, a receiver face axially opposed to the sealing face, the receiver face including a first receiver face in combination with the casing defining a first pressurization chamber in communication with the suction port, a second receiver face in combination with the casing defining a second pressurization chamber in communication with the discharge port, a third receiver face in combination with the casing defining a third pressurization chamber, and a communication path having an opening on the sealing face and communicating the opening with the third pressurization chamber.