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Why does a limited slip cause the rear to go sideways?

Tech questions that don't fit above forums

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Kevin Johnson
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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Tue May 07, 2019 2:59 pm

I am guessing that Benz used a technology similar to a freewheel ratchet on a bicycle. Might get real exciting on certain road surfaces. It doesn't look like chordal action would be too much of a concern.

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Wed May 08, 2019 1:08 am

It still maintains a differential, or "Jack-in-the-box" as they were known as in ancient times.

No freewheel ratchets required, especially as reverse gear was often needed.

Chain drive was a brilliant solution to negating "skinny tire lifting" from brute Engine torque.

Each tire and chain runs independent of the other so I dont think chordal action is an issue.

Either tire could out run the other while turning/steering on hard dry surfaces as needed.

Either tire could out speed the other but with rotational torque eliminated spin was lessened.

Any excitement was no doubt provided by the 600 CU - IN Simplex Engine!!

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Kevin Johnson wrote:
Tue May 07, 2019 2:59 pm
I am guessing that Benz used a technology similar to a freewheel ratchet on a bicycle. Might get real exciting on certain road surfaces. It doesn't look like chordal action would be too much of a concern.
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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Wed May 08, 2019 11:37 pm

Here is an interesting 3d rendering of the original Benz -- it appears that a twisted belt is used.

https://zaneliu94.github.io/benzmotorwagen/

I am curious as to when the presence of an open or standard differential became common with dual chain drive versus a spool type.

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Fri May 10, 2019 3:04 am

I'm certainly no expert but I'm positive the original Benz incorporated a differential.

As I remember the differential was invented by the chinese centuries before the first Automobile.

They made a mechanical device that served as a compass to find their way home.

I can't think of any early vehicle that didn't use a differential but there must have been some.

Bertha Benz wouldn't have been able to steer the Patent Motorwagen without one!!

Thanks
Randy


Kevin Johnson wrote:
Wed May 08, 2019 11:37 pm
Here is an interesting 3d rendering of the original Benz -- it appears that a twisted belt is used.

https://zaneliu94.github.io/benzmotorwagen/

I am curious as to when the presence of an open or standard differential became common with dual chain drive versus a spool type.
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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Fri May 10, 2019 3:16 am

GLHS60 wrote:
Fri May 10, 2019 3:04 am
I'm certainly no expert but I'm positive the original Benz incorporated a differential.
Yes, it does -- it is a pair of bevel gears above the motor which then goes to the belt which reverses the rotation. Bevel gears are still a differential, just not an open one.

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Fri May 10, 2019 2:18 pm

Respectfully, I believe the actual "open differential" is within the "countershaft assembly".

The "countershaft", powered by the Engine belt, contains the integrated differential within.

Each countershaft output has a chain sprocket and each chain powers a wheel individually.

Movies of it driving and steering show effortless turning not possible with a "spool".

Thanks
Randy

The very last paragraph explains "Power Transmission"

https://www.andrew.cmu.edu/course/24-68 ... st-car.pdf



Kevin Johnson wrote:
Fri May 10, 2019 3:16 am
GLHS60 wrote:
Fri May 10, 2019 3:04 am
I'm certainly no expert but I'm positive the original Benz incorporated a differential.
Yes, it does -- it is a pair of bevel gears above the motor which then goes to the belt which reverses the rotation. Bevel gears are still a differential, just not an open one.
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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Fri May 10, 2019 3:56 pm

Yes, you are correct -- there is a spider gear g^2 constrained somehow in the forward hub. I thought to locate the US Patent and look at the multiple drawings there.* However the patent verbiage is contradictory to examples of the motorcar and even the patent drawings themselves and I wonder if people chose to simply leave the spider gear out. I say this because it states that one of the drive chains to the rear wheels needs to be crossed due to the counter rotation of the second bevel gear and I have not observed this anywhere.

* The German Patent shown on the Daimler-Benz website is no help.

Here is the link to the US patent: https://pdfpiw.uspto.gov/.piw?docid=003 ... =PN/385087
Benz differential.jpg

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Fri May 10, 2019 5:11 pm

I must say it's enjoyable to converse with someone 10--no, 100 times smarter than myself!!

Someone so much smarter but with the ability to communicate with someone much less educated.

You make Speedtalk so wonderfully informative, Mark O'Neal is pretty good too.

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Randy
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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Fri May 10, 2019 5:26 pm

The check is in the mail. :lol:

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Fri May 10, 2019 7:37 pm

Good!!

I was hoping you wouldn't send me an invoice LOL

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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Fri May 31, 2019 9:48 pm

https://www.youtube.com/watch?v=DL_mJeb6O04

No crossed chain so I think the differential has been disabled.

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Sat Jun 01, 2019 12:59 am

I'm not sure what you mean, "crossed chain"??

Did you notice the "crossed" drive belt??

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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Sat Jun 01, 2019 9:37 am

GLHS60 wrote:
Sat Jun 01, 2019 12:59 am
I'm not sure what you mean, "crossed chain"??

Did you notice the "crossed" drive belt??

Thanks
Randy
https://patents.google.com/patent/US385 ... =385%2c087

The crossed drive belt is also not correctly illustrated in the patent. There is a separate visual and verbal description of the drive chains.

The illustrated front hub differential uses two equal diameter bevel gears communicating through a single small bevel gear which would generate mutually counter rotating drive shafts.

I think that Mercedes does not present the whole patent as this would kind of jump out to a mechanical engineer. The important part is that it is a motor driven horseless carriage.

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Re: Why does a limited slip cause the rear to go sideways?

Post by GLHS60 » Sat Jun 01, 2019 7:09 pm

Kevin Johnson wrote:
Sat Jun 01, 2019 9:37 am


https://patents.google.com/patent/US385 ... =385%2c087

The crossed drive belt is also not correctly illustrated in the patent. There is a separate visual and verbal description of the drive chains.

Possibly, the crossed belt reverses direction, maybe that's why the mention of crossed drive chains?? the visual is clear, the verbal not so much. Benz may have been influenced by this earlier patent?? https://patents.google.com/patent/US168 ... =385%2c087

The illustrated front hub differential uses two equal diameter bevel gears communicating through a single small bevel gear which would generate mutually counter rotating drive shafts.

Respectfully, I think you are misreading this. One ought to substitute "could" for "would" as in any open differential. COULD generate mutually counter rotating drive shafts. Would might apply if the wheels were off the ground.

I think that Mercedes does not present the whole patent as this would kind of jump out to a mechanical engineer. The important part is that it is a motor driven horseless carriage.

I would say it is an "Engine" driven Horseless Carriage or even an "Engine" driven motor vehicle.

The term motoring means to travel in a powered conveyance, possibly powered by a steam Engine, electric motor or Internal Combustion Engine!


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Re: Why does a limited slip cause the rear to go sideways?

Post by Kevin Johnson » Sat Jun 01, 2019 8:06 pm

Aber die sind doch Motoren!

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