Bearing Damper Ring Leakage Control for Intermediate Stiffness

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Solution Overview

Problem

Existing turbomachinery bearing assemblies face challenges in achieving optimal stiffness to effectively dampen radial forces and vibrations, as current oil damper cavities often result in either unsatisfactorily low or high stiffness levels, lacking an intermediate level suitable for specific applications.

Innovation Solution

The introduction of a damper ring with controlled leakage portions, which are strategically recessed to allow a controlled flow of oil, axially terminating the oil damper cavity and impeding leakage, thereby adjusting the stiffness of the bearing assembly by varying the size, shape, and configuration of these portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an oil damper cavity is introduced between the housing and the bearing outer ring, then radial forces and vibrations can be dampened, but the stiffness level becomes either unsatisfactorily low or high, lacking an intermediate optimal level

Engineering Contradiction:
Improveradial forces and vibrationsVSAvoidstiffness level adjustment
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The damper ring introduces localized quality variation by providing controlled leakage portions at specific locations on the bearing outer ring. These portions allow selective oil flow control, creating different stiffness characteristics in different radial zones. This enables the bearing assembly to achieve an intermediate optimal stiffness level that uniformly dampens vibrations while maintaining adaptability for specific applications.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the physical parameter of oil flow control by introducing controlled leakage portions that regulate the amount of oil passing through the damper ring. By adjusting the size and configuration of these leakage portions, the system can achieve different stiffness levels, including an intermediate optimal level that was previously unavailable with conventional oil damper cavities.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the oil damper cavity is designed to accommodate relative radial displacement by pressure variation, then vibration damping is achieved, but the stiffness cannot be optimized for specific applications

Engineering Contradiction:
Improvepressure variation for dampingVSAvoidstiffness optimization
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The damper ring segments the oil damper cavity into controlled regions by introducing leakage portions that divide the oil flow path. This segmentation allows different zones of the bearing assembly to experience different pressure variations, enabling optimized stiffness characteristics for specific applications while maintaining effective vibration damping through controlled pressure changes.

Inventive Principle:
Principle #1Segmentation

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

This configuration provides a balanced stiffness level, effectively dampening radial forces and vibrations by allowing a controlled amount of oil leakage, thus optimizing the bearing assembly's performance between low and high stiffness extremes.

Implementation Method 1

The introduction of a damper ring with controlled leakage portions, which are strategically recessed to allow a controlled flow of oil, axially terminating the oil damper cavity and impeding leakage, thereby adjusting the stiffness of the bearing assembly

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 2

The oil damper cavity can be designed to be fed with a certain flow rate of oil during operation, and to accommodate a certain extent of relative radial displacement between the bearing outer ring and the housing by pressure variation

Methodology Applied
Scientific EffectHydraulic damping: Hydraulic Press

Data Source

PatentEP3981995B1Bearing assembly, associated method of damping, and damper ring thereof
Publication Date: 2023.11.29 PRATT & WHITNEY CANADA CORP
  • EP3981995B1 patent drawingFigure 1
  • EP3981995B1 patent drawingFigure 2~2A
  • EP3981995B1 patent drawingFigure 3~4

AI summary

The bearing assembly (20) can extend between a rotor (44) and a housing (48), have a plurality of bearing rolling elements (40) mounted for rotation within a bearing ring (42), an oil damper cavity (46) between the bearing ring (42) and the housing (48), an oil inlet path (50) to feed the oil damper cavity (46), and at least one damper ring (52) defining a corresponding axial limit to the oil damper cavity (46) and having a radially inner edge (60) received in a corresponding annular groove (56) defined in the bearing ring (42), and a radially outer edge (62) having at least one arc portion (76) extending radially outwardly relative the annular groove (56) and engaging the housing (48), and at least one controlled leakage portion (70) radially recessed from the housing (48) and forming a leakage path leading axially out from the oil damper cavity (46).