Centrifugal Pump Impeller Reducing Axial Thrust
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Solution Overview
Problem
Centrifugal pump impellers face significant axial thrust issues due to pressure differences, leading to efficiency losses and motor bearing overload, particularly in multi-stage pumps, and existing solutions require precise angular positioning of disc-like elements, increasing manufacturing complexity and cost.
Innovation Solution
An impeller assembly with a first disk-like element facing a second disk-like element of smaller diameter, connected by angularly spaced blades with appendices that extend inside a circular crown, reducing axial thrust and allowing for simplified assembly without precise angular positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional impeller design is used, then the pump can operate, but axial thrust becomes very strong causing efficiency losses and motor bearing overload
Solution Approach 1:
The impeller is segmented into two separate disk-like elements (first and second disks) that are not rigidly connected. This segmentation allows each disk to independently respond to pressure forces, with the flexible connection between them enabling differential movement that reduces axial thrust transmission to the motor bearings while maintaining pump operation
Solution Approach 2:
The connection between the two disks is made flexible rather than rigid, allowing the structural parameters to change dynamically under load. This flexibility enables the impeller assembly to adapt its configuration in response to pressure differences, reducing the transmission of axial thrust to the bearings
2Stress or pressure
If multistage pumps are used to increase pressure, then delivery pressure is improved, but axial thrust generation is intensified causing overloading
Solution Approach 1:
The impeller assembly is divided into multiple independent impeller units, each consisting of two disk-like elements with flexible connections. This segmentation allows each impeller stage to independently manage its axial thrust through flexible deformation, preventing cumulative thrust overload on the motor bearings while achieving high delivery pressure through multiple stages
3Manufacturing precision
If disc-like elements are connected with specific angular positioning, then manufacturing precision is improved, but device complexity and manufacturing time increase
Solution Approach 1:
The connection between the two disk-like elements is made flexible, changing the structural parameter from rigid fixed positioning to flexible adaptive positioning. This eliminates the need for precise angular positioning during assembly, as the flexible connection allows the disks to self-align, thereby reducing device complexity and manufacturing time while maintaining operational precision
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 significantly reduces axial thrust while maintaining maximum efficiency and simplifies manufacturing, preserving motor bearings and reducing component count, thus lowering costs.
Implementation Method 1
said appendices being placed substantially in correspondence of areas subject to lesser axial thrust inside said circular crown
Implementation Method 2
centrifugal pump impellers are generally composed of pairs of disc-like bodies, suitably shaped, facing each other in such a way as to form a cavity within which is located a set of blades
Data Source
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AI summary
The present invention relates to an impeller assembly for centrifugal pumps, comprising a first disk-like element, operatively arranged towards a coaxial inlet, facing a second disk-like element with a smaller diameter, operatively arranged towards the outlet; this second disk-like element is rigidly connected to the first disk-like element through a set of angularly spaced blades, and is centrally provided with fastening means for fastening to a drive shaft. The distinctive feature of the present invention is that the blades comprise appendices, in flat sheet form, adjacent to the second disk-like element, which are essentially located in correspondence with areas subject to lesser axial thrust.