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Comment by OldManAndTheCpp | Hacker News Reader

A cool thing I learned from watching AvE's channel is that bearing surfaces are meant to last forever if properly lubricated. The oil in them is meant to take all the load, and the metal surfaces should never touch. If you don't replace the oil regularly, or let it get so hot it flows out of the journal, the bearing will wear and need replacing. The design is meant to last a really long time if properly serviced and not overloaded though. (I'd love to hear from a MechE if I misunderstood, I'm just a dumb programmer who watches YouTube).

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Thats pretty much right. Excluding how some types of bushings work, and other similar bearing surfaces.

Side note. There also air bearings which are also pretty awesome but require tight machining tolerances. They are used in the semiconductor industry for some things. Mainly because you dont want lubricant to dirty the enviroment, but the tighter tolerances also help ensure a spindle/shaft dont wobble as much.

I assume this means it's airtight and instead of a cushion of oil, it uses a cushion of (presumably compressed) air?

Yea pretty much. This video starts off with a nice demo of the concept.

https://youtu.be/sFrVdoOhu1Q

Great, thank you. As an aside, I love listening to people with accents explain things, so the video was doubly enjoyable!

Edit some time later: And then perhaps I'll go down an hours-long rabbit hole watching all his videos and learning a ton about machining...

>I love listening to people with accents explain things

Are there people without accents that explain things? Because that would be a video I want to see.

I suppose by "without accent" you mean "with General American accent"? German or French can be spoken without accent, but English doesn't have one universally agreed "standard accent". What's without accent to the American is just an American accent to everyone else.

This isn't completely true: even within America, there's different accents. So people with a "standard American accent" (generally midwestern) listen to Southerners talk and say they have an accent. There's also northeastern accents (such as the famous Boston accent).

Of course, these days, a lot of the accents are disappearing because of mass communications, so the "American accent" is homogenizing, but those other accents aren't completely gone yet.

I take the parent's comment to mean that everybody has an accent. There's no such thing as neutral or reference-frame speech.

The word "accent" implies that it is being compared to some kind of reference. You might be looking for the word "dialect" here.

For example, if you have two speakers with English as a first language and a third from Germany with English as a second language, the native English speakers will probably detect a German accent in the ESL-speaker's dialect.

People get into long internet arguments over this, but the closest thing to a neutral English dialect is General American English, also sometimes called Broadcast English because newscasters, TV personalities, and actors would be trained this dialect so as to not sound like they are "from" anywhere in particular. It used to be common as well for highly-educated or upper-class individuals to hire speech coaches to teach them this dialect in order to "lose their accent". It still may be common for all I know, but I believe the deliberate acquisition of General American is probably on the decline.

That's just an American-centered view-point though. Just because an accent dominates doesn't mean it's not an accent.

Obviously I mean foreign accents when speaking English.

AvE makes a lot of generalizations. What he says about technical topics is generally right enough for anyone who doesn't make a living designing the things he discusses. Those people would do well to understand the underlying theory.

>If you don't replace the oil regularly, or let it get so hot it flows out of the journal, the bearing will wear and need replacing.

It's still going to wear out from cold starts and the entire rest of the engine that doesn't have pressurized lubrication is also going to wear out eventually so there's no point in trying to outlast all those components since you're gonna have to take it apart to deal with them when they reach EOL and you can just deal with bearings at the same time.

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