Stabilizing Vertical Shaft Radial Vibrations
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Solution Overview
Problem
Rotating vertical shafts in subsea pumps and compressors experience instability due to lightly-loaded conditions, leading to radial vibrations and potential rotor failure, which existing solutions like tilting-pad bearings and eccentrically mounted bearings do not adequately address.
Innovation Solution
Applying lateral loading to the rotating shaft through a fluid under pressure, using a pressure delivery system that bleeds working fluid from suction and discharge pressures to exert precise pulling and pushing forces at strategic locations along the shaft, stabilizing it effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tilting-pad bearings are used to support the vertical shaft, then the shaft can be supported structurally, but radial vibrations and instability phenomena occur due to lightly-loaded condition
Solution Approach 1:
The patent applies hydraulic pressure from the process fluid itself to generate lateral loading on the shaft through pressure delivery openings in the bearing housing. This hydraulic approach creates stabilizing forces that counteract radial vibrations and instability phenomena without requiring additional mechanical complexity.
Solution Approach 2:
The system uses the working fluid already present in the machine to provide the stabilizing lateral loading. The process fluid's pressure is utilized through pressure delivery openings to act on the shaft, eliminating the need for external stabilization systems and making the system self-sufficient.
2Reliability
If eccentrically mounted bearings are used to generate radial load, then shaft stability may be improved, but device complexity increases
Solution Approach 1:
The patent introduces asymmetry through strategically positioned pressure delivery openings in the bearing housing that create lateral loading on the shaft. This asymmetric pressure distribution provides stabilizing radial forces without requiring eccentric bearing mounting, thus maintaining structural simplicity while achieving stability.
Solution Approach 2:
Instead of complex mechanical eccentric mounting, the patent uses hydraulic pressure distribution through strategically located openings to generate the necessary radial loading. This approach achieves stability through fluid pressure rather than mechanical asymmetry, reducing device complexity.
3Reliability
If lateral loading is applied through complex external systems, then shaft stability improves, but ease of manufacture and operation deteriorates
Solution Approach 1:
The system leverages the existing working fluid and pressure delivery infrastructure already present in the machine. By utilizing the process fluid's pressure through openings in the bearing housing, the system achieves shaft stabilization without requiring external complexity, making it easy to manufacture and operate.
Solution Approach 2:
The working fluid serves multiple functions: it performs the machine's primary process function and simultaneously provides stabilizing lateral loading on the shaft through pressure delivery openings. This multi-functionality eliminates the need for separate stabilization systems, simplifying manufacture and operation.
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 stabilizing arrangement provides enhanced stability to rotating vertical shafts by applying controlled lateral loading, reducing radial vibrations and preventing rotor failure, while being simple and cost-effective to implement.
Implementation Method 1
This is obtained through a pulling or pushing pressure acting on the rotating shaft. This is generated directly or indirectly by a fluid under pressure in the machine
Data Source
Figure 1
Figure 2~4
AI summary
The arrangement allows to stabilize a rotating shaft. It comprises a shaft (12) being arranged substantially vertically in a machine (10) so as to rotate during machine operation, first pressure delivery system(22, 23, 30) for delivering a fluid pressure, in particular of a fluid circulating inside the machine (10), at a first location (1) of the machine (10). Said first location (1) is close to the shaft (12) and part of said first pressure delivery system (22, 23, 30) is arranged at said first location (1) so as to exert a lateral pulling or pushing action on the shaft (12).