Thrust Foil Bearing Structure Without Weld-Induced Distortion
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Solution Overview
Problem
The existing thrust foil bearings face issues with top foil deformation due to heat from welding, leading to distortion and a reduction in load capacity, as the top foil may detach from the base plate and fail to form a sufficient fluid lubricating film.
Innovation Solution
A thrust foil bearing design that uses a top foil with a slit dividing it into inner and outer areas, featuring a sandwiched part and an extending part to attach the top foil to the base plate without welding, ensuring the top foil remains stable and prevents distortion by sandwiching it between the base plate and an annular member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the top foil is attached to the base plate using welding, then the top foil is securely fixed to prevent detachment, but the top foil may be deformed due to heat from welding causing distortion
Solution Approach 1:
The patent replaces the thermal welding process with a mechanical sandwiching structure. The top foil is positioned between the base plate and a cover plate, secured by bolts that apply mechanical pressure rather than heat. This substitution eliminates thermal deformation while maintaining secure attachment, resolving the contradiction between attachment reliability and manufacturing precision.
2Strength
If the top foil is securely attached to maintain load capacity, then the bearing can support sufficient load, but welding causes heat deformation that reduces load capacity
Solution Approach 1:
The patent replaces thermal welding with mechanical sandwiching using bolts and a cover plate. This mechanical attachment method avoids heat-induced deformation that would compromise the top foil's flatness and load-bearing capability, thereby maintaining both strong attachment and high load capacity.
Solution Approach 2:
The top foil is designed as a thin, flexible component that can conform to the bearing surface while maintaining its structural integrity. The sandwiching structure allows the thin foil to be securely held without rigid welding, preserving its ability to form a proper lubrication film while preventing heat deformation.
3Strength
If welding is used to attach the top foil, then the attachment is strong and secure, but the heat from welding causes distortion affecting fluid lubricating film formation
Solution Approach 1:
The patent replaces welding with a mechanical sandwiching system using bolts and a cover plate. This eliminates thermal effects that would distort the top foil and compromise its ability to form a proper fluid lubricating film, while still providing strong and secure attachment through mechanical means.
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 design effectively prevents top foil distortion and maintains the load capacity of the thrust foil bearing by securely attaching the top foil through sandwiching, enhancing its stability and performance by preventing detachment and deformation.
Implementation Method 1
The rotation of the thrust collar causes lubricating fluid to flow into a gap between the top foil piece and the thrust collar. The lubricating fluid forms a wedge-shaped fluid lubrication film between the top foil piece and the thrust collar, and the load capacity of the thrust foil bearing is obtained.
Data Source
AI summary
A thrust foil bearing includes: a base plate including an insertion hole through which a shaft is inserted; and a top foil disposed around the insertion hole, wherein the top foil includes: a slit dividing the top foil into an inner area and an outer area in a radial direction of the insertion hole; a sandwiched part disposed in the outer area; an extending part extending from the sandwiched part to the inner area; and an inclined part being in the inner area, having an end on one side in a circumferential direction of the insertion hole connected to the extending part, extending from the extending part toward another side in the circumferential direction, and inclined with respect to a flat surface of the base plate extending a direction orthogonal to an axial direction of the insertion hole.