Gentlemen,
So far, it seems that everyone is claculating the friction force, however, the formulas used are not mentioning the length of the circular sleeve bearing. Therefore, the bearing length in contact with the shaft must be multiplied by the friction force in your equations to acheive the...
Jim,
Ball & Roller thrust bearings are not simple to troubleshoot, many factors can combine to cause unusual loading. However, you are correct in thinking that the high temperatures are due to some type of installation problem, and not merely due to increasesd axial hydraulic pump load. Here...
Hello,
Machine Design magazine carries monthly advertisements for Fuji(the camera film company)pressure sensitive paper , which gives different colors depending on the actual pressure. Its exactly what you need.
Uacar,
Standard hydraulic mineral oils are only designed to handle a maximum of 120 degC. Any greater than this, and the oil will severly breakdown and oxidize. That is why you need to purchase synthetic hydraulic oils, because they can accept up to 250 degC, with no deterioration.
Uacar,
You have neglected an important point. You say that the circulating oil temperature is only 40 degC. However, the oil trapped in the hydraulic cylinder located at the gas turbine exhaust area, is being cooked at very high temperatures, because when the hydraulic piston is not being...
Here is my technical guess:
The hollow baseball shaft now has a surface which deflects inwards more then when the bat was solid wood, during the impact of the ball. This increased elasticity increases the time of impact(in microseconds),which then increases the energy transferred from the bat...
Massey,
If the shaft rpm does not exceed 500 rpm, then why not use graphite sleeve bearings, with captured grease lubrication, such as using O-rings rubbing lightly on the shaft.
Massey,
Interesting replies from everyone....I like difficult problems like this, it takes the cobwebs off of my brain.
Here is one more solution: Use radial stainless steel ball bearings, in addition to a single stainless steel ball-thrust bearing, which is placed at the shaft shoulder, just...
To Mike Bensema,
Thanks for pointing out the german article on greased bearings. However, everytime I download, it does not open, as I think the file is corrupted. I would certainly appreciate it if you would do me a favor and send the file you downloaded, to my e-mail address...
Massey,
I think you have an interesting problem, and in fact, I once had a boat trailer with heavy corrosion on the roller bearings of the wheels. Here is one solution:instead of installing stainless steel bearings to resist the leakage inward of corrosive water, why don't you use standard...
Hi,
Here is another solution, its called stage-eight locking devices. It has a positive locking system that should resist all vibration.
http://www.stage8.com/Groovelok.htm
Naturally, any bolted joint can lose some preload from thermal cycling, vibration, gasket/joint relaxation. To prevent...
Hi webber,
Here is a very simple method of determining the optimum torque. First, get a torque wrench, and install the brass bolts into a suitable temporary joint. Add the nut and torque slowly, adding force increments until the bolt thread is sheared, or the threads shear.
Now you know the...
We have a lot of experience with RO pumps. Use SUNDYNE(american pump manufacturer) high speed integral geared centrifugal pumps, as these are a perfect fit for seawater RO applications. Don't waste time with any one else.
Hello,
There is one ASTM number for INVAR that I am aware of and that is ASTM-B-388.However, like I said earlier, make sure that the material used has a tensile yield strength of 70,000 to 80,000 psi( by heat treatment or coldworking).Search under "INVAR" in the internet, and contact...
Hi. The best place to start is to purchase several battery powered mini-refrigerators, such as the kinds sold for use in automobiles(12vots).Try automotive accessory catalogs, and search the internet under the title"automotive refrigerator" or similar words.From there, you can design...
