OT: Sprag/clutch bearings need not be aligned?

[John Doe]

When two clutch bearings are used in parallel, there is no need to
align them, right? They do not have pawls, the clutching begins
precisely at the point at which they reverse direction? So if you
put two in parallel, there is no benefit to aligning them so that
they grip in unison?

I'm not saying two will be perfectly functional in parallel, the
distance to grip might be microscopically different with each
bearing, I'm just double checking that one requirement. But if you
have an opinion about them being functional in parallel, go for it.
I will research this stuff at some point.

Thanks.

 

Just what are you talking about ? Are you building an automatic transmission for a car ?

If the application is anywhere near the same the orientation should not matter. As long as all the rotating members, which will of course all be rotating when it is engaged are balanced,l it doesn't meant shit. The only time it does is when you need the phase of the driver and driven to be synced, and in such a case you do not use the type of clutch.

The only way with that type of clutch is to have a member on it which prevents application until they are in sync, and that fights the actuator and that is a waste of power.

More information about the application wold help. You CAN do this but you don't rally want to. You have to lead her a migh... as Jed said to Jethro. Ad by thee way I owud give them a run for their shooting money. I can, or at least could hit aa bird in flight with a handgun. But understand the reference, this clutch will take time to actuate, and that is going to vary because of temperature, maybe humidity, maybe what you had on your pizza last Friday.

Too many variables, unless you want to wast energy by mechanically keying it. And don't even think about "feathering" it if you want it reliable. You will wear it out. Lie the clutch on your car, there is no wear when your foot is off it and there is no wear when it is on the floor. It is that in between time just like with electronics. No current all voltage is cool, all current and no voltage is cool. But the to together are the destroyers.

I would like to know why you need to do this. Why not stepping motors or somethings ?

 

John Doe <always.look@message.header> wrote in news:qnsnfn$6be$1@dont-
email.me:

jurb6006@gmail.com wrote:

Just what are you talking about ?

I am talking about arranging two Sprag/clutch bearings in parallel
on a shaft so they act as one with (ideally) twice the torque
handling ability.

It is for a drive wheel with a 35mm bore. A clutch bearing (CSK15PP)
fits into both sides of the hub.

Since when does a bearing "handle torque"?

 

[John Doe]

jurb6006@gmail.com wrote:

> Just what are you talking about ?

I am talking about arranging two Sprag/clutch bearings in parallel
on a shaft so they act as one with (ideally) twice the torque
handling ability.

It is for a drive wheel with a 35mm bore. A clutch bearing (CSK15PP)
fits into both sides of the hub.

 

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:7114ae2b-
354b-49a3-9922-a1d17473ab32@googlegroups.com:

> https://en.wikipedia.org/wiki/Sprag_clutch

Bearings are used to make a sprag clutch, but the bearings
themselves are not bearing the torsional forces, the sprags and
housing are.

It is essentially a one way optimized ratchet clutch where the
ratchet locking elements are called sprags, so they called it a sprag
clutch. The "bearings" are there to allow smooth operation in the
locking direction and provide centering of the center section.

We should have called them sprag wrenches I guess, instead of
ratchets.

Two such clutches in series can handle more torque, but I would not
simply double the expectation because the shaft might overpower one
before the other, or the one that happens to be slightly weaker than
the other will break first. Kind of like parallel diodes.

 

[Lasse Langwadt Christense]

lørdag den 12. oktober 2019 kl. 16.30.26 UTC+2 skrev DecadentLinux...@decadence.org:

John Doe <always.look@message.header> wrote in news:qnsnfn$6be$1@dont-
email.me:

jurb6006@gmail.com wrote:

Just what are you talking about ?

I am talking about arranging two Sprag/clutch bearings in parallel
on a shaft so they act as one with (ideally) twice the torque
handling ability.

It is for a drive wheel with a 35mm bore. A clutch bearing (CSK15PP)
fits into both sides of the hub.


Since when does a bearing "handle torque"?

when it is a one way bearing

https://en.wikipedia.org/wiki/Sprag_clutch

 

[John Doe]

AlwaysWrong going from not knowing what it is, to acting like
an expert on the subject, in two replies...

--
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From: DecadentLinuxUserNumeroUno decadence.org
Newsgroups: sci.electronics.design
Subject: Re: OT: Sprag/clutch bearings need not be aligned?
Date: Sat, 12 Oct 2019 15:39:50 +0000 (UTC)
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Lasse Langwadt Christensen <langwadt fonz.dk> wrote in news:7114ae2b-
354b-49a3-9922-a1d17473ab32 googlegroups.com:

https://en.wikipedia.org/wiki/Sprag_clutch

Bearings are used to make a sprag clutch, but the bearings
themselves are not bearing the torsional forces, the sprags and
housing are.

It is essentially a one way optimized ratchet clutch where the
ratchet locking elements are called sprags, so they called it a sprag
clutch. The "bearings" are there to allow smooth operation in the
locking direction and provide centering of the center section.

We should have called them sprag wrenches I guess, instead of
ratchets.

Two such clutches in series can handle more torque, but I would not
simply double the expectation because the shaft might overpower one
before the other, or the one that happens to be slightly weaker than
the other will break first. Kind of like parallel diodes.

 

[Rick C]

On Saturday, October 12, 2019 at 11:11:10 AM UTC-4, Lasse Langwadt Christensen wrote:

lørdag den 12. oktober 2019 kl. 16.30.26 UTC+2 skrev DecadentLinux....@decadence.org:
John Doe <always.look@message.header> wrote in news:qnsnfn$6be$1@dont-
email.me:

jurb6006@gmail.com wrote:

Just what are you talking about ?

I am talking about arranging two Sprag/clutch bearings in parallel
on a shaft so they act as one with (ideally) twice the torque
handling ability.

It is for a drive wheel with a 35mm bore. A clutch bearing (CSK15PP)
fits into both sides of the hub.


Since when does a bearing "handle torque"?

when it is a one way bearing

https://en.wikipedia.org/wiki/Sprag_clutch

Wikipedia has its limitations. This article is one of them. It needs some good illustrations. This is better, about 9 rows down the page there is a diagram rather than photos. Clicking on that shows some other drawings with various additional info.

https://www.google.com/search?client=firefox-b-1-d&tbm=isch&sxsrf=ACYBGNRYb35tITLKRVHe62dA2mMOlm4ZlQ:1570905486905&q=sprag+clutch&chips=q:sprag+clutch,g_1:starter:5jjYSZvXR5g%3D&usg=AI4_-kTJXxqPnRNXbVNqv34iCVKkyTzLkw&sa=X&ved=0ahUKEwim7Zb8rpflAhWCmOAKHXm5CUYQ4lYIMCgD&biw=1020&bih=560&dpr=1.76#imgrc=KbYYvTnytKK9WM:

--

Rick C.

- Get 2,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

I am talking about arranging two Sprag/clutch bearings in
paralle on a shaft so they act as one with (ideally) twice the >torque handling ability.

It doesn't work that way. Each clutch has to transmit the same torque, all you are doing is doubling the possibility of failure.

If you want to parallel two clutches like that you need gears to run two shafts, one clutch on each and then gears to recombine the torque.

Another option is just to get clutches with the same plates and all but of 1.5 times the diameter. If you want to combine clutch plates in the manner you describe you have to take them apart and rebuilt them into one unit. If you are going to do that there are plenty of option, like just getting the right clutch.

Another thing is if there is a gear train anywhere or you can do one, double the RPM of the shaft and then halve it after. This will give the one clutch double the power handling capability but then the RPM is of course double. Think of torque and power almost like amps and watts. Double the RPMs and you double the voltage so your switch only has to handle half the current.. If you just series two switches the same current flows.

The easiest option is to buy the right clutches, if you got a bunch of these laying around and can't use them consider selling them off. You can either get clutches with the same number of plates and sprags which is like 1.5 times the diameter, actually pure math it is 1.414, just like electronics, but there is some headroom like in the middle and whatever so figure 1.5, maybe 1.6. But if ONE clutch has twice as many plates, it accomplishes about the same thing.

 

[Lasse Langwadt Christense]

søndag den 13. oktober 2019 kl. 03.26.14 UTC+2 skrev DecadentLinux...@decadence.org:

John Doe <always.look@message.header> wrote in news:qnstlv$ej9$1
@dont-email.me:

AlwaysWrong going from not knowing what it is, to acting like
an expert on the subject, in two replies...


I never acted in any such way, you stupid fuck.

And in one reply, you, as usual prove that you are a retarded
asswipe. And you do not even have to act like it. You LIVE it,
asswipe!

You couldn't even get the arrangement description right. They are
in series, dipshit. Just because you face two together and the faces
are parallel, does not change the fact that they are in series on the
shaft they are on. They bear a load in parallel, and there is where
I spoke about one not being exactly the same as the other and hence
one would always fail at a point before the other, just like parallel
diodes do.

using your weird terminology, would that be diodes physically in parallel or electrically in parallel ?

 

John Doe <always.look@message.header> wrote in news:qnstlv$ej9$1
@dont-email.me:

AlwaysWrong going from not knowing what it is, to acting like
an expert on the subject, in two replies...

I never acted in any such way, you stupid fuck.

And in one reply, you, as usual prove that you are a retarded
asswipe. And you do not even have to act like it. You LIVE it,
asswipe!

You couldn't even get the arrangement description right. They are
in series, dipshit. Just because you face two together and the faces
are parallel, does not change the fact that they are in series on the
shaft they are on. They bear a load in parallel, and there is where
I spoke about one not being exactly the same as the other and hence
one would always fail at a point before the other, just like parallel
diodes do.

You need to gro the fuck up.

 

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:18e40be8-c24b-4e5d-a226-1ce50355e0b8@googlegroups.com:

søndag den 13. oktober 2019 kl. 03.26.14 UTC+2 skrev
DecadentLinux...@decadence.org:
John Doe <always.look@message.header> wrote in news:qnstlv$ej9$1
@dont-email.me:

AlwaysWrong going from not knowing what it is, to acting like
an expert on the subject, in two replies...


I never acted in any such way, you stupid fuck.

And in one reply, you, as usual prove that you are a retarded
asswipe. And you do not even have to act like it. You LIVE it,
asswipe!

You couldn't even get the arrangement description right. They
are
in series, dipshit. Just because you face two together and the
faces are parallel, does not change the fact that they are in
series on the shaft they are on. They bear a load in parallel,
and there is where I spoke about one not being exactly the same
as the other and hence one would always fail at a point before
the other, just like parallel diodes do.

using your weird terminology, would that be diodes physically in
parallel or electrically in parallel ?

If you want them to last, BOTH. They need to be very proximal to
each other such that their temperature rises together in unison,
because not doing so is why they experience failure modes related to
thermal runaway because one diode takes over the whole task.

In this mechanical scenario, both clutches are likely rated the
same, and would likely test very very close to each other, so a
failure mode of one then the other is unlikely. It would happen, but
only at the very point where both are about to fail. One would go
first.

 

jurb6006@gmail.com wrote in
news:38d0aacd-1119-4364-bd5a-8c937099aa13@googlegroups.com:

It doesn't work that way. Each clutch has to transmit the same
torque, all you are doing is doubling the possibility of failure.

They would both lock. And if more torque was applied than the
rating of one, it would likely not fail, because the load would be
being shared between them as the both locked.

Look at a non-posi rear end. One wheel or the other locks.

However, if you put air bag shocks on the thing, it sets up a
vibration that locks both sides and you get both tires on a non-posi
rear. Fact.

I do not know the mechanism in the spider gears and such... at
least not intamately. I only know this because my brother did it,
and we were pushing that lame ten bolt with a 427 rat too.

 

not being exactly the same as the other and hence
one would always fail at a point before the other, just like >parallel diodes do.

Not the worst analogy but fits. Maybe I am wrong a little about it being like electronics. Still similar.

Alright, let's take two diodes in series. If you need more current that will do not shit for you. the limitation on current is still the same, the PRV doubles but that is not what you need.

I think we had this about parallel diodes before, I think the consensus was if you need the current just get the bigger rated diode you need. Paralleling diodes is as bad as transistors.
I actually designed a circuit a while back to balance unbalanced transistors, actually it was for MOSFETS. That is harder ecause with bipolar the transistor with less gain automatically gets more drive. Not so with MOSFETS.

Maybe I'll LTSpice it and post it. Couple things not worked out, the system would oscillate between devices, its effect has to have a limit so it has to be determined just how much imbalance do we want it to tolerate. So much GM to so much Gm it can handle but no more.

Anyway, the asker (OP), mechanics is not electronics. I was tops in mechanics in school. Well not just school, the test had me at the 99th percentile, that means tops more than just that school.

 

jurb6006@gmail.com wrote in
news:38d0aacd-1119-4364-bd5a-8c937099aa13@googlegroups.com:

It doesn't work that way. Each clutch has to transmit the same
torque, all you are doing is doubling the possibility of failure.

Sure it does. Single shaft, two sprag clutches, means the connection
between the shaft and the driven clutch hub is greater. So as long as
the shaft can apply more torque, the load would get shared between both
clutches.

 

[Lasse Langwadt Christense]

søndag den 13. oktober 2019 kl. 04.05.21 UTC+2 skrev DecadentLinux...@decadence.org:

jurb6006@gmail.com wrote in
news:38d0aacd-1119-4364-bd5a-8c937099aa13@googlegroups.com:

It doesn't work that way. Each clutch has to transmit the same
torque, all you are doing is doubling the possibility of failure.


Sure it does. Single shaft, two sprag clutches, means the connection
between the shaft and the driven clutch hub is greater. So as long as
the shaft can apply more torque, the load would get shared between both
clutches.

once the "tightest" clutch lock what locks the second clutch?

 

[John Doe]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

DecadentLinux...@decadence.org:

Single shaft, two sprag clutches, means the connection between
the shaft and the driven clutch hub is greater. So as long as
the shaft can apply more torque, the load would get shared
between both clutches.

once the "tightest" clutch lock what locks the second clutch?

Likely there would be some practical difference, however tiny, between
the two. And if you assume enough pressure will be applied to cause the
first locked bearing to slip a tiny bit (or overextend, whatever), does
that cause damage. But maybe they slip a tiny bit in normal operation.
Also possible is that it would degrade the first clutching bearing until
it's sloppy enough so that both engage at precisely the same time, but
that might be a fishy theory.

Somebody mentioned it on one of the cycling forums years ago. I have
done some searching but have found nothing.

 

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:381953e9-761c-4c23-abb8-04f2787df77b@googlegroups.com:

søndag den 13. oktober 2019 kl. 04.05.21 UTC+2 skrev
DecadentLinux...@decadence.org:
jurb6006@gmail.com wrote in
news:38d0aacd-1119-4364-bd5a-8c937099aa13@googlegroups.com:

It doesn't work that way. Each clutch has to transmit the same
torque, all you are doing is doubling the possibility of
failure.


Sure it does. Single shaft, two sprag clutches, means the
connection

between the shaft and the driven clutch hub is greater. So as
long as the shaft can apply more torque, the load would get
shared between both

clutches.

once the "tightest" clutch lock what locks the second clutch?

They both lock together they are not allowed to "say no".

And the shaft goes through both.

IF one were to fail to act as a clutch by failing to lock, the
system would still work as long as the torque is still below the
capacity of either because the other DID lock.

But in normal use, both lock and both share loading.