Thank you for your videos. I would like to know if there is any requirement for mounting direction for this type of bearing? Because at 1:45 of the video the attitude angle of the left and right bearings are different and the direction of gravity is not labeled in the diagram.
Thank you for your question and for watching the video! You're absolutely correct-foil bearings generally require a specific mounting orientation and rotation direction to function optimally. These bearings are typically designed for a preferred rotation direction, as the geometry and preload are optimized for stability under those conditions. While they can handle reverse rotation to some extent, they may quickly become unstable due to the lack of proper hydrodynamic pressure generation. Additionally, the load direction is indeed a critical consideration. Foil bearings are designed to support loads in specific orientations, and incorrect loading can compromise their performance or stability. If you found this explanation helpful, feel free to share it with your colleagues who might also be interested in foil bearing design. I appreciate your engagement and thoughtful feedback!
@@RotorDynamics Thank you for your reply and explanation, it is very helpful. For the bearings shown in the video, can you give a recommended load direction? Because at 1:45 of the video, the photo and the schematic show different angles for the foil bearings, and there is about a 30° difference between them(assuming gravity is all vertical down), which is better ?
Thank you for your kind feedback! I appreciate your attention to detail regarding the foil bearings. For a thorough discussion on load direction and the differences observed, I recommend emailing me directly at rotordynamics101@gmail.com. I’d be happy to clarify further there.
I'm thrilled to hear that you find the videos helpful! Your feedback encourages me to continue simplifying complex topics. If there's anything specific you'd like to see covered or if you have any questions, feel free to let me know. Thank you for watching and for your kind words!
Excellent question! While Part 17 video delves into clearance details, it may not cover the specific information you're seeking. If you could provide more details on your inquiry, I'll be happy to create a customized video offering an in-depth design guide tailored to your needs. :)
Excellent question! Numerous efforts have been made to substitute oil lubricated bearings with gas foil bearings, particularly in applications such as HVAC compressors. However, it's crucial to understand that a direct replacement is not feasible. This is primarily due to the fact that gas bearings generally offer lower stiffness compared to oil bearings, as the working fluid is gas instead of oil. Consequently, in order to accommodate the same weight of the shaft and other forces that need to be counteracted, the gas bearing typically needs to be larger in both diameter and length.
Great question! In the video, it's explained that the shafts are elevated by hydrodynamic effects from gas foil bearings. As the shaft spins, these effects generate increased force. At lower speeds, there's less of this hydrodynamic effect, which can lead to wear on the gas foil bearings. To address this wear issue in certain applications, external compressed air is sometimes employed to lift the shaft.
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Thank you for your videos. I would like to know if there is any requirement for mounting direction for this type of bearing? Because at 1:45 of the video the attitude angle of the left and right bearings are different and the direction of gravity is not labeled in the diagram.
Thank you for your question and for watching the video! You're absolutely correct-foil bearings generally require a specific mounting orientation and rotation direction to function optimally.
These bearings are typically designed for a preferred rotation direction, as the geometry and preload are optimized for stability under those conditions. While they can handle reverse rotation to some extent, they may quickly become unstable due to the lack of proper hydrodynamic pressure generation.
Additionally, the load direction is indeed a critical consideration. Foil bearings are designed to support loads in specific orientations, and incorrect loading can compromise their performance or stability.
If you found this explanation helpful, feel free to share it with your colleagues who might also be interested in foil bearing design. I appreciate your engagement and thoughtful feedback!
@@RotorDynamics Thank you for your reply and explanation, it is very helpful. For the bearings shown in the video, can you give a recommended load direction? Because at 1:45 of the video, the photo and the schematic show different angles for the foil bearings, and there is about a 30° difference between them(assuming gravity is all vertical down), which is better ?
Thank you for your kind feedback! I appreciate your attention to detail regarding the foil bearings. For a thorough discussion on load direction and the differences observed, I recommend emailing me directly at rotordynamics101@gmail.com. I’d be happy to clarify further there.
Thank you for the videos, clearly a topic that lacks simple explainations like you do.
I'm thrilled to hear that you find the videos helpful! Your feedback encourages me to continue simplifying complex topics. If there's anything specific you'd like to see covered or if you have any questions, feel free to let me know. Thank you for watching and for your kind words!
Do u have any videos or info onto how to dimension ur top foil and bump foil?
Excellent question! While Part 17 video delves into clearance details, it may not cover the specific information you're seeking. If you could provide more details on your inquiry, I'll be happy to create a customized video offering an in-depth design guide tailored to your needs. :)
Thank you for sharing the knowledge on gas foil bearing. Can we replace oil lubricated bearings with foil bearing? Suggest few applications.
Excellent question! Numerous efforts have been made to substitute oil lubricated bearings with gas foil bearings, particularly in applications such as HVAC compressors. However, it's crucial to understand that a direct replacement is not feasible. This is primarily due to the fact that gas bearings generally offer lower stiffness compared to oil bearings, as the working fluid is gas instead of oil. Consequently, in order to accommodate the same weight of the shaft and other forces that need to be counteracted, the gas bearing typically needs to be larger in both diameter and length.
Excellent video.... What is the source of this compressed air for lifting the shaft? Is it internal (bleed air) or external?
Thanks.
Great question! In the video, it's explained that the shafts are elevated by hydrodynamic effects from gas foil bearings. As the shaft spins, these effects generate increased force. At lower speeds, there's less of this hydrodynamic effect, which can lead to wear on the gas foil bearings. To address this wear issue in certain applications, external compressed air is sometimes employed to lift the shaft.
@@RotorDynamics Thanks for the excellent explanation.... Keep us educating.... Thanks...
Very unique information in TH-cam 👍
Thank you so much! I'm thrilled to hear that you found the information unique. Your support means a lot! 😊👍
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Looks like you mentioned a few names there-anything specific you'd like to discuss or ask about? 😊 Let me know how I can help!