Questions tagged [tribology]
14 questions
9
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2 answers
What causes friction in magnetic bearings?
Magnetic bearings work by levitating a rotating shaft so that it is not in contact with its supports. This greatly reduces the friction of the system.
In all of the literature that I have seen on magnetic bearings, the bearings are described as "low…
hazzey
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What makes crosshead bearings hard to lubricate?
Regarding crosshead bearing failure, I have read that at slow speed it is difficult to establish a lubricating film because there is an imbalance between forces due to combustion and forces due to inertia. This information is from a maker of big low…
veronika
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Which lubricant (oil or not) to use if I want to prevent sticky/gummy buildup?
I am currently tinkering with typewriters and two things striked me when I started to read about their maintenance:
They are supposed to run almost completely dry, except for a very tiny amount of lubricant at very specific points;
Gummy or sticky…
heltonbiker
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3
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Is there any material that has a higher kinetic friction than static friction?
Is there a material that has higher kinetic friction than static friction?
You can assume it's sliding on any surface you want.
Better if you come up with one that has this property on a standard flooring material: steel, wood, smooth concrete,…
dpdt
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What's the name of the white lubricant that children's toys often use?
When I was little I would often take apart my toys and found that if they contained any gears or motors they'd always be coated in a white lubricant. What is this substance?
Noah
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1
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1 answer
equivalent Hertzian contact pair for arbitrarily shaped bodies in 2D
I am a bit new to this field here. I am trying to determine the contact stress between two arbitrarily shaped bodies that are indenting into each other (see attached image). I would like to solve for the contact stress using an equivalent…
shiwa
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1 answer
Does the the field of tribology include the study of adhesives?
Does the field of Tribology include the study of adhesives in addition to the study of lubricants?
user148298
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Significance of the Sommerfeld number
The Sommerfeld number can be written as
$$ S = \frac{6 \ \mu \ U \ b}{p \ c^2} $$
where
U: Velocity
b: Width
p: Pressure
c: Minimal Clearing
$\mu$: Absolute Viscosity
As far as I'm aware, it may be used for both thrust and journal bearings. It is…
Rover
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Applications with combination of high friction and low wear?
What would be some common applications involving high friction and low wear rates? for example, gear-driven mechanisms which require high friction between the gear teeth but ideally low wear between them.
spe4ker
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Terminology for engine life reduction due to late oil changes
This is a question for engineers working in diesel engine design or tribology. I am doing up an analytics dashboard for my father who analyses oil samples of heavy mining equipment. The diesel fitters there have moved to a calendar based maintenance…
0
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1 answer
Entrainment Speed in Ball Bearing
Assuming no slip between the inner race and the outer race of a ball bearing, what is the entrainment speed between the balls and the inner race? The inner race is rotating at $\omega_i$ and the outer race is fixed, $\omega_o = 0$, as shown…
Geoffry
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Positive and negative voltage readings across a rig simulating bearing contact, supplied with a DC source
I recently ran a few experiments to simulate the effects of shaft voltages on motor bearings through using a simplified experimental rig. The rig simulates bearing contact. I applied a DC source across the rig using carbon slip rings and connected a…
Mrcemify
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1 answer
Approach to solve a frictional problem?
I am having a bar and surface (made of aluminum). I need to attach some material to the end of the bar so that, if I apply any force (25 N-sideways) to bar it has to stick with the surface.
Force is applied normally to the flatter surface of the…
Alt C
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Power needed to accelerate metal powder through two spinning wheels
I have a wheel which has a radius of 0.1m that needs to spin at 10000RPM. The outer surface of this wheel is pressed up against another free spinning wheel like a football or tennis ball launcher.
I am feeding metal powder through these two wheels,…
david_10001
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