Shaft Mounting Spring Assembly for Vibration Damping and Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for reducing vibrations in rotating machinery, such as oil squeeze films and sealing rings, face issues with component misalignment and rapid wear, especially when exposed to high loads and hot fluids, leading to reduced effectiveness over time.
Innovation Solution
A shaft mounting assembly featuring a stiff, high-rate spring with a substantially circular discontinuous band that provides radial anti-vibration and centralizing effects, allowing sealing rings to focus on sealing while the spring handles radial loads, and utilizing a stacked spring arrangement to increase spring rate without reducing radial travel range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sealing rings are used to provide centralising and damping effects, then sealing and damping functions are achieved, but the sealing rings wear out quickly due to high loads and hot fluids
Solution Approach 1:
The invention divides the functional responsibilities by introducing a separate spring component that handles radial loading and centralising functions, while the sealing ring focuses exclusively on sealing. This segmentation allows each component to be optimized for its specific function, reducing wear on the sealing ring.
Solution Approach 2:
The centralising and damping functions are extracted from the sealing ring and transferred to a dedicated spring component. This extraction relieves the sealing ring from bearing radial loads, allowing it to maintain its sealing effectiveness without suffering from rapid wear caused by mechanical stresses.
2Object-affected harmful factors
If radial clearance is provided for oil squeeze film damping, then vibration damping is improved, but component misalignment problems occur
Solution Approach 1:
The spring acts as an intermediary component between the shaft and the housing bore. It provides the necessary damping and centralising effects while maintaining precise alignment, mediating between the need for radial clearance for damping and the requirement for manufacturing precision.
3Force
If sealing rings are subjected to high radial loads, then they provide necessary damping and centralisation, but they wear out quickly and become less effective
Solution Approach 1:
The invention segments the load-bearing and sealing functions by introducing a dedicated spring component to handle radial loads. This allows the sealing ring to maintain reliable sealing performance over time by eliminating subjecting it to high radial loads that cause wear.
4Temperature
If hot fluid is present in the gap between shaft and housing, then thermal effects occur, but the chemical structure of sealing ring material breaks down causing deformation
Solution Approach 1:
The sealing ring is extracted from the hot fluid environment by positioning it in a groove that isolates it from the thermal zone. This protects the material's chemical structure from breakdown while the spring component handles the mechanical functions in the thermal environment.
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 spring assembly effectively reduces vibrations, prolongs the lifespan of sealing rings by distributing radial loads, and maintains concentric alignment of the shaft within the cylinder, providing both radial and axial resilience and compliance.
Implementation Method 1
a spring comprising a substantially circular discontinuous band... the spring has a de-energised state in which the height of the band is greater than the depth of the groove... and an energised state in which the spring is compressed within the bore
Implementation Method 2
The spring can be a stiff, high-rate spring to provide radial anti-vibration action, and also to provide a centralising effect between the shaft and the cylinder
Data Source
Figure 1a~1b
Figure 2A~2C
Figure 3
AI summary
Herein is described a shaft mounting assembly comprising an elongate shaft (32) comprising an outer surface having a substantially circular cross-section; a cylinder (35) having an inner surface defining a bore, the bore housing the shaft, wherein the inner diameter of the cylinder is larger than the outer diameter of the shaft such that a gap (40) is defined between the outer surface of the shaft and the inner surface of the cylinder; and, a spring (10, 210) comprising a substantially circular discontinuous band having correspondingly shaped axially arcuate inner and outer surfaces. One of the outer surface of the shaft and the inner surface of the cylinder comprises a groove (34, 234); and wherein the groove extends around the circumference of the outer surface of the shaft or the circumference of the inner surface of the cylinder respectively. The spring is positioned in the groove such that both axial edges of the band are located within the groove. The spring has a de-energised state in which the height of the band is greater than the depth of the groove, so that a portion of the band between the axial edges protrudes out of the groove, and the axial width of the band is less than the width of the groove; and, an energised state in which the spring is compressed within the bore such that the height of the band is reduced, and the axial width of the band is increased compared to the de-energised state.