Axial Thrust Balancing via Variable Fluid Gaps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing axial thrust balancing mechanisms in rotating shaft devices face challenges in providing self-regulating and complete thrust compensation while avoiding contact and wear between rotating and static elements, especially in high-pressure applications like multistage pumps.
Innovation Solution
A hybrid thrust regulating mechanism that combines features of balancing disks and drums, featuring a rotor and stator configuration where the rotor is coaxial with the stator but positioned adjacent to it, allowing a pressure relief gap that varies in size and direction with axial shaft displacement, providing self-regulating thrust compensation without direct contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a balancing disk is used to provide self-regulating thrust compensation, then thrust compensation effectiveness is improved, but contact and wear between rotating and static elements occurs
Solution Approach 1:
The patent replaces the traditional mechanical contact-based balancing disk system with a magnetic field-based active thrust compensation system. Magnets mounted on the rotating shaft generate magnetic fields that interact with stationary magnets or magnetic sensors in the housing, enabling thrust balancing without physical contact between rotating and static components.
Solution Approach 2:
The patent utilizes fluid pressure differentials created by the rotating shaft's movement through the housing to generate compensating thrust forces. By strategically positioning pressure relief gaps and fluid channels, the system converts axial displacement into pressure-driven counter-thrust without requiring direct mechanical contact.
2Object-affected harmful factors
If a balancing drum is used to avoid contact and wear, then reliability is improved, but thrust compensation completeness deteriorates
Solution Approach 1:
The patent employs dynamic adjustment mechanisms where the positions or strengths of magnetic fields or fluid pressure zones change in real-time based on the rotating shaft's axial position. This dynamic response enables complete thrust compensation while maintaining the non-contact advantage of balancing drums through active control rather than passive fixed geometry.
3Reliability
If opposed impellers are used to offset thrust, then thrust compensation is improved, but device complexity increases
Solution Approach 1:
The patent extracts the thrust compensation function from the impeller stages themselves and implements it as a separate, dedicated mechanism. This allows the impellers to focus solely on their primary pumping function while the independent magnetic or fluid-based thrust compensation system handles axial force balancing, simplifying the overall system architecture.
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 hybrid mechanism achieves nearly complete cancellation of axial thrust with minimal risk of contact and wear, effectively compensating for at least 90% of the thrust generated, maintaining low residual thrust levels and enhancing feedback effects through variable pressure relief gaps.
Implementation Method 1
a pressure relief gap is formed between the leading edge of the male section and the front edge of the female section through which pressurized fluid is able to flow from the second segment, past the first segment, to a low pressure region
Implementation Method 2
The pressure relief gap is reduced in size by the axial displacement of the rotatable shaft, such that the compensating force is increased when the axial thrust and axial displacement are increased
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
An axial thrust balancing mechanism for a rotating shaft apparatus such as a rotary pump provides self-regulating thrust compensation while avoiding contact and wear between rotating and static elements. A rotor fixed to the shaft includes a cylindrical male section proximal to but not extending within a cylindrical female section of a non-rotating stator, such that a gap formed therebetween is varied in width by axial thrust shaft displacements. Pressurized fluid within the female section applies a thrust-compensating force to the rotor that is controlled by the gap size. The female section is larger in diameter than the male section, preventing any contact therebetween. The disclosed mechanism can be combined with a thrust-compensating drum to reduce the thrust to a residual level that can be regulated. The rotor and stator can be stepwise varied to provide a plurality of gaps and intermediate chambers therebetween.