Back-to-Back Counter-Rotating Impellers for Axial Thrust Balance
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Solution Overview
Problem
Existing fluid movement systems, such as compressors, experience excessive axial loading on thrust bearings due to unbalanced thrust forces, limiting their differential pressure capacity.
Innovation Solution
A counter rotating back-to-back fluid movement system with interleaved impellers arranged in opposed directions to balance thrust forces, reducing axial loading on bearings while maintaining flow and pressure capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single impeller configuration is used to move fluid, then fluid flow is achieved, but excessive axial loading occurs on thrust bearings
Solution Approach 1:
The fluid movement system is segmented into multiple impellers (first impeller and second impeller) arranged in a back-to-back configuration. Each impeller handles fluid flow independently while generating opposing thrust forces, thereby segmenting the axial load burden and reducing the net axial loading on the thrust bearing assembly.
Solution Approach 2:
The second impeller is configured to generate a thrust force that opposes the thrust force of the first impeller, creating a counterbalancing effect. This anti-weight principle reduces the net axial load on the thrust bearing assembly while maintaining the fluid flow capacity of both impellers.
2Stress or pressure
If differential pressure capacity is increased in conventional compressors, then higher pressure output is achieved, but axial loading on thrust bearings increases excessively
Solution Approach 1:
The compression function is segmented across multiple impellers arranged in series, where each impeller contributes to the overall differential pressure generation. The back-to-back configuration allows each impeller to generate pressure while its thrust force is counterbalanced by the opposing impeller, enabling high differential pressure capacity without proportional increase in axial loading.
Solution Approach 2:
The impellers are arranged in a back-to-back configuration along the axial dimension, creating a symmetric thrust force distribution. This dimensional arrangement allows the thrust forces to oppose each other in the axial direction, effectively reducing net axial loading while maintaining the ability to generate high differential pressure through the series arrangement of impellers.
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 system effectively reduces axial loading on thrust bearings by balancing thrust forces, allowing for higher differential pressures without increasing load limits, thus enhancing operational efficiency.
Implementation Method 1
the impellers are configured so that when the drive shaft rotates the impellers move water in opposite axial directions so that axial forces of the two impellers offset each other
Data Source
Figure 1
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AI summary
A technique facilitates movement of fluids while reducing axial loading on system components such as thrust bearings. The technique utilizes a system, e.g. a compressor, for moving fluid via counter rotating rotors. By way of example, the rotors may utilize impellers for establishing opposed fluid flows along fluid movement sections. The fluid movement sections may be arranged in a back-to-back configuration such that counter rotation of the rotors causes the impellers to move fluid flows in opposed directions, thus reducing axial loading. The opposed fluid flows ultimately are redirected to an outlet.