Journal Bearing Design & Analysis w/ Charts | Reynolds Equation; Minimum Film Thickness; Power Loss

LECTURE 23
Also see Lecture 22, where the Sommerfeld Number is introduced through the derivation of the Petroff Equation: • Hydrodynamic Journal B...
Playlist for MEEN462 (Machine Element Design):
• MEEN 462: Machine Elem...
Playlist for MEEN361 (Advanced Mechanics of Materials):
• MEEN 361: Advanced Mec...
This lecture was recorded on October 29, 2018. All retainable rights are claimed by Michael Swanbom.
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Thank you for your support!

[@energiam880]

I can't thank you enough for these lectures! I did a Ph.D. in bearings, but it was all about the metallurgical and manufacturing aspect of them! Now I find myself as the chief engineer at a bearing company, and your videos have saved me reading through a lot of literature on the design aspect of bearings!

[@shadabs000]

His Students are very lucky to have a teacher like him

[@TheBomPE]

I appreciate the affirmation! Thanks for watching!

[@TheBomPE]

If you found this video useful, consider helping me upgrade the old tablet PC I use to create these videos! Thanks! www.gofundme.com/help-replace-my-2011-tablet-pc

[@liranunezdavid]

I did this exercise in SI considering: F_r=2670 N; D=60mm; n=2800rpm; L/D=0.5; SAE40; tolerance H7b9. Got: nominal temperature=72C; h_0=0.015mm; S=0.0676; film position=30; viscosity=21.55 mPa-s (or cP); p_max= 5.7MPa; maximum pressure position=14,5; Q=21.95cm^3/s; Q_s=12.29cm^3/s; friction coefficient f=0.009; power loss P=0.28HP.

[@khanoftheskyzzz6742]

Great to have you !

[@TheBomPE]

Good to be here!

[@av5186]

Thank you for your great lecture.

[@TheBomPE]

I'm glad you enjoyed it! Thanks for watching!

[@GAS-OR-ASS]

Very intuitive guidelines. Very nice video thank you

[@maxtop34]

sir very helpful and much valuable video,thank you so much!

[@TheBomPE]

I'm glad you found it helpful! Check out my other Shigley-based playlists too: MEEN361: kzbin.info/aero/PL1IHA35xY5H5AJpRrM2lkF7Qu2WnbQLvS and MEEN462: kzbin.info/aero/PL1IHA35xY5H5KqySx6n09jaJLUukbvJvB Thanks for watching!

[@Aabhran]

Hi, great lecture! One question, how do I determine the lubricating oil pressure going into the bearings? I ask this because I work at a thermal power station plant and we monitor the pressure and temperature.

[@naidu2308]

it was nice video sir......can you please clarify me, whether bush/bearing is to be designed only for internal pressure (Pmax) in similar to pressure vessel?

[@vilaskalyankar43]

Nice one 🎉

[@absorbit8]

Hello. Thank you for your videos. I am wondering is there a specific requirements for contact surface between housing and shell? What max gap is allowed?

[@sadikselia1427]

Great Lecture!! Can you the name the textbook from which the graphs are taken. Also I have this doubt that shouldn't lubrication problems also include surface tension (any adhesive force) because that would define how the fluid stays attached to the metal surface. Although in this case it makes sense since we are constantly pushing liquid (through the dynamic motion of the journal), but what about cases where there are 2 flat surfaces moving slowly w.r.t each other but the contact force is very high. So here some adhesive force should play an important role right?? Otherwise the fluid might just squeeze out of the contact surface due to the load.

[@hammadqidwai8052]

shigley

[@KaarthicKaundabalaraman]

What is the absolute viscosity range for which the charts are designed I tried with the operating temperature of 120degree C the clearance values are not matching with the defined design clearance

[@absorbit8]

Hello. Thank you for your helpful video. It is much better than grey soviet books. Tell me what, please. Is the dynamic viscosity coefficient is the same as absolute viscosity? Because there is in soviet books they utilize that parameter instead of absolute viscosity?

[@nadhimnaseer5493]

is there any description about attitude angle ?

[@absorbit8]

And I didn't quite catch why did you choose F=150 for calculation?

[@novalkurnianto7918]

Could you explain to me. How to calculate the power loss? In 55:10 you add the formula with the blue mark, what is it?

[@TheBomPE]

Those are conversion factors. There are 2*pi radians in 1 revolution, there are 60 seconds in 1 minute, and there are 6600in*lb/s in 1 horsepower (hp).

[@israelgzz99]

What if the shaft is fixed and the bushing is the one rotating? Thank you in advance.

[@TheBomPE]

I based this lecture in Shigley's Mechanical Engineering Design, 10th ed. Shigley says that you find the "significant angular speed" with the absolute value of (Nj + Nb - 2Nf) where Nj is the journal speed (the inner part), Nb is the bearing speed (the outer part) and Nf is the rate of rotation of the load (see eq 12-13). Based on this, the case you are asking about would not be computed differently than the case demonstrated in the example in the video. Thanks for watching!

[@AravindUkrd]

Wonderful lecture :) One doubt though: Why is it that the projected area of the journal diameter taken to calculate the fluid pressure and not that of the the bearing (which contains the fluid) diameter.

[@TheBomPE]

Thanks for the positive feedback! In answer to your question: there are very small clearances between the journal and the bearing relative to their overall size. This means the diameters of these two parts are practically the same. When computing projected area, it doesn't make enough difference to worry about. Thanks for watching!

[@AravindUkrd]

@@TheBomPE thank you 🙂

[@novalkurnianto7918]

If i design the reservoir, can i use this calculation?

[@TheBomPE]

I'm sorry, I'm not sure what you are asking. Best of luck!

[@alenforjanic290]

Very nice video! Can you please answer me, if my l/d=1,23. Which curve should I choose?

[@TheBomPE]

One way to deal with charts like this (not only for journal bearings, but for just about any chart with multiple curves) when you have a number that does not exactly pick one of the curves, is to interpolate. I have a sample of how this can be done in this video: kzbin.info/www/bejne/e2bXmHeMg5atr5Y

[@alenforjanic290]

@@TheBomPE thank you for fast reply! Right after the comment I found interpolation equation for Raimondi-Boyds 😅 … is there any way to analytically compare non-grooved bearing with grooved bearing ? So which one is “better” to use for certain application.

[@muhammadsaboor1142]

How to find minimum pressure

[@nadhimnaseer5493]

can you give me the link of this journal bearing book sir

[@TheBomPE]

For this video I was working out of Shigley's Mechanical Engineering Design, 10th edition.

[@zeeshanhydersahito4618]

This lecture is good about journal bearings , I need some help in the aerostatic bearings design, can you please help me, if possible, I will wait for your kind response.

[@TheBomPE]

I do not currently have any instructional materials prepared about that topic, but I will keep it in mind as a potentially interesting topic on which to do a lecture. Thanks for watching!

[@zeeshanhydersahito4618]

@@TheBomPE Dear sir thanks for kind reply, I hope you will make a good lecture on how to design a model and get simulation results by using ANSYS Workbench as well as by using charts to compare the result with experimental results. Please sir if possible guide me about the designing and simulation of Aersostatic thrust bearing and Aerostatic journal bearing with pockets, tilt pads and orifices. Dear sir I will wait your best response, sir if You have any book on aerostatic bearings, please send me.

[@nadhimnaseer5493]

I need your help in journal bearing .........I am phd student .....i need your gmail or any way to contact with u

[@laythzubairi6429]

Can I communicate with you

[@novalkurnianto7918]

600lb. How can i get it?

[@TheBomPE]

With respect to this example problem, 600lb is a given value. (See 6:10 .) In a real-world context, you would have to evaluate what load capacity your proposed bearing would need to have based on the job it would be doing.

[@novalkurnianto7918]

Sir, how i can calculate the load of bearing? And determine the characteristic of the lubricant?

[@valentinodrachuk5692]

Great lecture, but wtf are those units. Just use international standards.

[@TheBomPE]

Thanks for the support. My guess is that you are not expecting to ever practice engineering in the US. Engineers practicing in the US need to be skilled with both unit systems.

[@tycho1123]

For fuck sake the use of the Imperial system disgusts me.

[@TheBomPE]

You are welcome to view the videos KZbin has that cover the content you want covered in the SI system. You don't have to watch the ones that disgust you.