Rotary Pump Bushing Assembly With Compensation Tanks Against Jamming

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Solution Overview

Problem

Current bushing assemblies in positive displacement rotary pumps experience surface abrasion and jamming due to uneven load distribution and friction, leading to performance degradation and reduced lifespan, especially under high-pressure conditions.

Innovation Solution

Incorporating pressurized compensation tanks and bleed channels within the bushing assemblies to redistribute stress and facilitate fluid bleeding, which helps in realigning the bushing assemblies and reducing surface pressure in high-stress areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional bushing assemblies are used in positive displacement rotary pumps, then the pump can operate with simple structure, but surface abrasion and jamming occur due to uneven load distribution and friction

Engineering Contradiction:
Improvebushing assembly structureVSAvoidbushing assembly performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The bushing assembly is segmented into functional zones through the introduction of compensation tanks and bleed channels. The compensation tank divides the bushing structure into a pressurized zone and a relief zone, creating distinct functional segments that address different aspects of load distribution and lubrication independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compensation tank acts as an intermediary element between the lubrication system and the bushing contact surfaces. It mediates the pressure distribution by storing pressurized lubricant and releasing it through bleed channels to the high-stress areas, thereby reducing direct friction and wear between moving parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If bushing assemblies operate under high-pressure conditions, then the pump can achieve high discharge pressure, but load concentration causes surface abrasion and jamming

Engineering Contradiction:
Improvedischarge pressureVSAvoidsurface abrasion and jamming
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The invention applies hydraulic principles by using pressurized lubricant in the compensation tank to counterbalance the mechanical loads on the bushing assembly. The hydraulic pressure generated in the compensation tank is directed through bleed channels to the high-stress contact areas, creating a fluid film that reduces friction and prevents surface abrasion and jamming.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The invention changes the pressure parameter distribution across the bushing assembly by introducing the compensation tank. Instead of uniform pressure, the system creates a variable pressure field where high pressure is applied to high-stress areas through bleed channels, while other areas experience lower pressure, thereby optimizing load distribution and reducing wear.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the bushing assembly structure is simplified, then manufacturing is easier, but stress concentration occurs in specific areas leading to reduced lifespan

Engineering Contradiction:
Improvebushing assembly fabricationVSAvoidbushing assembly lifespan
Core Design Contradiction:
Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The bushing assembly is segmented into functional zones through the introduction of compensation tanks and bleed channels. The compensation tank divides the bushing structure into a pressurized zone and a relief zone, creating distinct functional segments that address different aspects of load distribution and lubrication independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by providing enhanced lubrication and pressure compensation specifically in the high-stress areas of the bushing assembly through bleed channels. Instead of uniformly complexifying the entire structure, the compensation tank and bleed channel system targets only the critical contact zones where load concentration occurs, thereby extending lifespan without proportionally increasing manufacturing complexity.

Inventive Principle:
Principle #3Local quality

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 solution effectively reduces surface abrasion and jamming, improving pump performance and extending the useful life by redistributing loads and minimizing stress concentrations, resulting in a 40% reduction in maximum effort and improved operational stability during transients.

Implementation Method 1

Incorporating pressurized compensation tanks and bleed channels within the bushing assemblies to redistribute stress and facilitate fluid bleeding

Methodology Applied
Scientific EffectPressure redistribution: Pressure Gradient

Implementation Method 2

at least one bleed channel that connects said compensation tank to a portion of the lateral surface facing the discharge side

Methodology Applied
Scientific EffectFluid flow through pressure gradient: Pressure Gradient

Implementation Method 3

The bushing assemblies are coupled in an internal cavity of a casing or pump body and are axially floating therewithin to allow packing the components due to the pressures acting on the opposite plane faces of the assemblies themselves

Methodology Applied
Scientific EffectFluid film lubrication: Lubrication

Data Source

PatentEP4073384B1Improved bushing assembly and positive displacement rotary pump comprising said bushing assembly
Publication Date: 2023.07.12 SETTIMA FLOW MECHANISMS SRL
  • EP4073384B1 patent drawingFigure 1
  • EP4073384B1 patent drawingFigure 2~3
  • EP4073384B1 patent drawingFigure 4

AI summary

Improved bushing assembly (10) for supporting the shafts of the intermeshed rotors of a positive displacement rotary pump avoiding, jamming, said bushing assembly (10) comprising on a lateral surface (13) thereof at least one compensation tank (15; 16) facing a suction side of the pump and at least one bleed channel (14) which connects said compensation tank (15; 16) to the discharge side.