Foil Air Bearing Notch Structure for Bidirectional Rotation
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Solution Overview
Problem
Existing foil bearings for turbine engines are limited to a single direction of rotation and require complex and costly machining operations for removable systems, necessitating the development of a bidirectional foil bearing that can be manufactured without specialized techniques.
Innovation Solution
A foil air bearing design featuring a cylindrical sleeve with longitudinal notches that allow radial tongues of the bump and top foils to be freely housed, enabling bidirectional rotation without fool-proofing means and simplifying manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional foil bearing designs with fixed ends are used, then the bearing can be manufactured with simpler structures, but it is limited to single-direction rotation and requires fool-proofing means
Solution Approach 1:
The foil bearing structure transitions from a static fixed-end design to a dynamic configuration where the foil can flex and adapt its position. The foil is attached at one end to the bearing housing and remains free at the other end, allowing it to dynamically adjust during bidirectional rotation without requiring fool-proofing means.
Solution Approach 2:
The bearing is divided into distinct functional segments: a fixed attachment portion at one end of the foil and a free moving portion at the other end. This segmentation allows the fixed end to provide structural support while the free end accommodates bidirectional rotation, eliminating the need for complex fool-proofing mechanisms.
2Ease of repair
If removable foil bearing systems are used, then the bearing can be easily replaced, but complex and costly machining operations are required
Solution Approach 1:
The foil bearing is pre-assembled as a complete unit within the bearing housing, with the foil attached at one end and positioned within the housing cavity. This preliminary assembly eliminates the need for complex post-installation adjustments or specialized machining operations for removal and replacement.
Solution Approach 2:
The bearing housing is designed with a universal structure that accommodates the foil bearing assembly as an integrated unit. The housing includes features such as a cavity for receiving the foil and attachment mechanisms that work for both installation and removal, simplifying manufacturing while enabling easy replacement.
3Strength
If non-removable welded foil bearing systems are used, then the bearing is securely fixed, but it cannot be separated from the sleeve once fixed
Solution Approach 1:
The attachment mechanism uses a dynamic balance between secure fixation and removable design. The foil is attached at one end with sufficient strength to prevent detachment during operation, while the overall assembly remains removable through the housing cavity, avoiding permanent welding while maintaining structural integrity.
Solution Approach 2:
The bearing housing acts as an intermediary structure that provides secure fixation during operation while enabling controlled removal when needed. The housing cavity and attachment features mediate between the need for strong fixation and the need for replaceability, eliminating the need for permanent welding.
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 design allows for bidirectional operation without the need for fool-proofing and simplifies the manufacturing process, reducing costs and complexity while maintaining radial play and ensuring proper alignment of the shaft.
Implementation Method 1
at least one bump foil (22, 23, 24), each bump foil (22, 23, 24) having, at each end, a radial tongue (22a, 22b, 23a, 23b, 24a, 24b), each radial tongue (22a, 22b, 23a, 23b, 24a, 24b) being freely housed in a longitudinal notch (40, 50, 60)... forming an elastically deformable lining
Implementation Method 2
Device forming an aerodynamic radial bearing with sheets and method for manufacturing such a device
Data Source
AI summary
The invention relates to a device forming a foil air bearing, comprising a cylindrical sleeve (10) extending along a longitudinal direction, and having an inner surface (11) which defines a central bore, characterized in that it further comprises: at least one longitudinal notch (40, 50, 60) formed in said cylindrical sleeve and opening radially into said central bore; a first peripheral inner lining, called the bump lining, comprising at least one metal foil equipped with radial projections, called the bump foil (22, 23, 24), each bump foil having, at each end, a radial tongue, called the radial bump tongue (22a, 22b, 23a, 23b, 24a, 24b), housed freely in a longitudinal notch (40, 50, 60); a second peripheral inner lining, called the top lining, comprising at least one metal foil, called the top foil (32, 33, 34), each top foil having, at each end, a radial tongue, called the radial top tongue (32a, 32b, 33a, 33b, 34a, 34b), housed freely in a longitudinal notch (40, 50, 60).