Comprehensive treatise on hydrodynamic bearings?

[rhb]

I am looking for a book which covers hydrodynamic bearings which must support both axial and radial loads. Despite having 10 ft of books on machine design, not one treats anything other than pure axial and pure radial bearing designs.

Application is a lathe spindle, so this has been studied to death, but neither google nor Amazon are able to provide any leads.

Bonus points for something that also covers hydrostatic and aerostatic bearings able to take combined axial and radial loadings.

I'm quite agog that in all those books, no one treated the combined load case. I *really* don't want to derive it and verify the solution. The derivation would be painful, but verification would be a long agony of devising test setups.

I'm looking for wall to wall math. No arm waving.

 

[Chestermiller]

Google "Hydrodynamc Theory of Lubrication."

 

[rhb]

Google "Hydrodynamc Theory of Lubrication."

Can you provide a more specific reference? You've simply suggested I do what I have already done for hours. I was rather hoping a human being could do better than a machine.

 

[Chestermiller]

I found the following, which I kinda like: http://wwwf.imperial.ac.uk/~ajm8/M3A10/lub.pdf

 

[rhb]

I wish I had confidence that the cylinder case applied to an arbitrary surface of revolution. I've got at least 10 treatments of a cylinder.

In the case of a lathe spindle, even a simple cone gets complicated because the combined axial and radial loading is in general not normal to the bearing surface. One also has to contend with the locking properties of shallow tapers.

I may be overestimating the difficulty, but I get very nervous when the loading is not normal to the bearing surface. Although expensive to make in quantity, an involute curve does allow for the loads to be normal to some portion of the bearing surface. But I have no clue how that affects the full solution as the normal condition only applies to a line or at most a narrow band.

I'm a retired research reflection seismologist. I tend to get nervous any time I don't know a *lot* more about the problem than I *need* to know. I don't like doing Wiley Coyote imitations. It doesn't hurt until you hit the ground, but then it really does.

I have a 5000+ volume technical library. I'm looking for one or more good books which treat the case to add to it. I posted the query because I got tired of reading tables of contents on Amazon which just duplicated what I already have.

 

[Baluncore]

Bearing Design in Machinery; Engineering Tribology and Lubrication.
Avraham Harnoy. 2005. ISBN 0-203-90907-0

Numerical Calculation of Elastohydrodynamic Lubrication.
Ping Huang. 2015. Wiley. ISBN 978-1-118-92096-1

Numerical Calculation of Lubrication.
Ping Huang. 2013. ISBN 978-1-118-45119-9

 

[rhb]

Thanks! I'll start with Harnoy. What is the distinction between the two books by Ping Huang? Is it worth getting both or is there a lot of duplication?

I have no objection to duplication, but I prefer that the repetition is written by different authors. Everyone bungles an explanation from time to time. So having more than one presentation by different authors can be a huge help.

Having spent a lot of time on elastoplastic deformation and fluid flow in porous media I should feel right at home ;-)

Edit:

Amazon lists a 2002 first edition by Harnoy, but it does not match the ISBN you gave. Interestingly, that was the most promising of the various books I looked at, but I couldn't read the relevant section. So I decided to ask a few places for suggestions.

Edit 2:

The ISBN for Harnoy above is the eBook version. I'll order the paper version in a few minutes.

BTW other book suggestions on the topic still welcome. I like to have more than one reference on complex subjects.

Edit 3:

I found a PDF of Harnoy. It's an excellent book, but does not treat conical or tapered bearings in any form. So I'm still looking.

 

[Baluncore]

You will find many interesting references if you go to BookFinder.com
Search for title; hydrodynamic bearings
Examples are;

Schuller Frederick T.
Design of various fixed-geometry water-lubricated hydrodynamic journal bearings for maximum stability [by] Fredrick T. Schuller. Prepared at Lewis Research Center. 1973

By R.J. Rossbach
Hydrodynamic Journal Bearing Test and Analysis / By R.J. Rossbach. 1970 [Super Deluxe Edition]

Jun Zhu & Lie Yu
Proceedings of the International Conference on Hydrodynamic Bearing- Rotor System Dynamics97(Chinese Edition)

Before you buy I recommend, you either; google books, view the book in a library, or get a pdf review copy.
When you want to buy, use BookFinder.com to find [new] or [used] alternatives, sorted by price.
Remember; https://www.physicsforums.com/threads/support-pf-buy-on-amazon-com-from-here.473931/

 

[rhb]

Schuller and Rossbach don't treat the taper case. Three lobe, tilting pad, RaIeigh step and herringbone variations are the main topics. I'm really amazed that it's as hard to find the information as it has turned out to be. I've now spent close to 8 hours looking through books in my library and online and found nothing even close.

Thanks for the Amazon link. I buy quite a few expensive books. 5% of my annual spend is significant.

Edit:

Progress at last! I fed "tribology of conical hydrodynamic bearings" to google scholar and got lots of relevant hits, though journal access is an issue. But at least I now know the magic incantation and the names of those who have worked on the topic.

FWIW the project is to rebuild a new 7x14 Chinese mini-lathe to the standards David Broadhead used when he rebuilt his 13" Southbend in preparation for making the screws for the ruling engine John Strong built at Johns Hopkins in the late 1940's. I am *not* going to attempt anything as difficult as those screws. But Albert Ingalls wrote some very interesting articles for the June and July 1952 issues of Scientific American about Broadhead's work. Scraping to a tenth I know how to do. Designing and making a high precision spindle bearing I do not. The Southbend used hydrodynamic bearings, but the mini-lathe uses a Chinese "ABEC 1" deep groove Conrad type bearing.

I have had a very nice 10x20 Clausing for 20 years, but reconditioning it to Broadhead's standards is daunting as it is a much larger machine and has hardened ways. So the mini-lathe seemed a reasonable warmup exercise. I've got a lot of metrology to master.

 

[Baluncore]

Interesting. I am also a once-geologist who rebuilds precision metal working machines and electronic instruments. Hence my parallel interest in spindle bearings. Like you I live in an extensive collection of technical reference books.

I found these;
Performance Analysis of a Conical Hydrodynamic Journal Bearing. June 2018.
Authors; Ajay Kumar Gangrade; Vikas M. PhalleS. S. Mantha
https://link.springer.com/article/10.1007/s40997-018-0217-2
The references listed at the end of the abstract are interesting. Example...
Murthy TSR (1981) Analysis of multi-scallop self-adjusting conical hydrodynamic bearings for high precision spindles. Tribol Int 301:147–150

I also had some luck with google images “ conical hydrodynamic bearings”.

 

[rhb]

My MS was in igneous petrology with the intent of going into mining, but when I graduated in 1982 all the mines in North America were closed other than coal and I *think* Sudbury. So I went into reflection seismology and had a lot of fun. I'd love to be able to work, but at present prices no one is looking oil in deepwater, so as with many friends, employment is not an option.

I sent an email to Harnoy asking for any suggestions he might have of a comprehensive analysis of conical bearings, but have not heard anything back yet. He's retired, so I may not get a response from his faculty address.

To get journal access I have to go to Little Rock to the UALR library. I've made 2-3 trips collecting IEEE papers. I don't yet know if they have ASME papers or not, but will find out soon enough.

You would not believe the abuse I got from the denizens of the 7x12minilathe list on groups.io. After a good bit of time with "Metal Cutting Principles" by Milton C. Shaw to obtain an estimate the maximum spindle forces possible from the OEM motor I calculated that the L10 life was 100,000 hours for a quality ABEC 1 deep groove Conrad bearing taking a maximal cut. So I wrote it up, scanned the appropriate sections from Shaw and the Torrington Service Catalog and posted it. It's become painfully clear why discussion of hobby lathes are prohibited on the PracticalMachinist forum. The result was a long series of personal attacks. No one ever addressed the issues I'd raised. The central complaint is I write about things, but don't post pictures of what I've done. Never mind that my lathe was damaged in shipping and I am still waiting to get the 6" and 12" cast iron straight edges I ordered from Martin Modles in early May which I shall have to mill and scrape before proceeding. And my MT 2, 3 & 4 test bars took over a month to arrive from India.

Of course, the idea that some stranger can demand I do what they want me to do is more than a little over the top.

There's a YouTube video by some Aussie who is "reconditioning" a mini-lathe. With the bed in an unknown state of stress, he puts the carriage on with the rear gib tight and notes that it binds at the headstock end, i.e. there is wind in the bed.

So he "fixes" it by gluing 100 grit silicon carbide paper to the vee, puts several layers of cardboard and masking tape on the flat section of the bed and proceeds to sand the carriage vee!

There was great enthusiasm for the video. So when I pointed out that the problems with what he had done they unloaded on me.

Not having trained as a mechanical engineer, the virtues of the mini-lathe were not immediately obvious. But the more I learn, the more impressed I am with the design. It's built to a very low price point, so the manufacturing QC is dubious, but so far my measurements indicate that it's actually decently made so long as you accept that you're going to need to scrape it if you want an accurate machine. And it is so much more solid than the 6" Atlas and Dunlap lathes sold by Sears or the Sherline, Taig and Unimat 3 there is no comparison.

My first post to the list outlined my intent to rescrape it to a tenth. That elicited a string of comments about how lousy they were and "He's a noob. Wait until he learns about backlash." I didn't bother to explain I knew a great many ways to make a nut with a backlash adjustment. I merely noted I'd owned a 10x20 Clausing 4902 lathe and 8x26 Clausing 8520 mill for 20 years. So now the complaint is that I post stuff based on literature research. So I am looking for another venue to document the process.

I sometimes spend a lot of time on the EEVblog forum which I have found very impressive. There are some *very* sharp people there. Quite a few of the higher skill people in electronics also have impressive metalworking shops and scientific skills.

I'd very much appreciate any suggestions you have with regard to the mini-lathe rebuild. I just received four 4"/2 mm level vials from AliExpress and have ordered swivel feet and 4 mm carbide balls. I've still got to suffer through ordering the rest of the parts, but am building a 3 point mount for holding the lathe for scraping and a version of a King Way. I have Connelly and did learn algebra, geometry and trig in high school, so I'm not going to copy King's design exactly. But at $12 a 4"/2 mm vial will give me a very sensitive measurement for almost nothing. There is more to the plan, but I'll send that as a PM.

Have Fun!
Reg

 

[Baluncore]

I have Connelly

For those who read this later, "Connelly" is THE reference.
Edward F. Connelly. 1955. Machine Tool Reconditioning and Applications of Hand Scraping.
Reprinted many times.

 

[rhb]

I think it fair to note that Richard King dismisses Connelly as a "mere votech teacher" based on his father having met Connelly. But Connelly's book is the canonical reference and well worth the price. Richard King has lots of experience rebuilding machines and teaching classes on scraping, but is simply doing what he learned from his father without any real understanding. Even a minor deviation from his father's prescribed process, such as scraping the cross slide and saddle so they can be used with a level to scrape the bed is unacceptable. Thou *must* scrape the bed first. Perfectly fine if you have the tooling to do that. But as Connelly points out, scraping machine parts first to aid in doing the mensuration may be greatly preferable on an economic basis.

The other major book is "Foundations of Mechanical Accuracy" by Wayne Moore of Moore Special Tools. It is available from Moore for $150 printed with a sewn binding on glossy paper. When I ordered my copy from Moore, there were two sellers on Amazon asking $4000 for a copy!

It's a very expensive book to print and simply has no equal. After WW II the Moore family transformed tool making. In 1970 they made a coordinate measuring machine with a resolution of 25 millionths of an inch. The ultimate machinist job is running Moore machines in a very comfortable constant temperature environment.

Moore invented an entire class of machine tools aimed at improving the productivity of the machinists responsible for making specialized tooling. With the advent of "nanotechnology" they have developed a line of tools to meet those needs.