Citroen and his gears

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Citroen and his gears

This topic has 13 replies, 10 voices, and was last updated 3 June 2017 at 19:01 by Carl Wilson 4.

Viewing 14 posts - 1 through 14 (of 14 total)

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1 June 2017 at 22:53 #300765
Hacksaw
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@hacksaw
There's me thinking for years the double arrow heads were representing hydraulic lift suspension…

So ,they're double helical gear teeth actually ! Every day's a school day..

How are they cut then ? I can see pics on the internet , of gears with a gap in the middle,so a cutting tool could run into the gap. and ones with a radius in the base of the V could be end milled ? . These ones appear sharp in the V though…

Edited By Hacksaw on 01/06/2017 22:55:24
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1 June 2017 at 22:53 #15944
Hacksaw
Participant
@hacksaw
1 June 2017 at 23:36 #300768
Nathan Sharpe
Participant
@nathansharpe19746
My best try is a two part rim/tyre construction pinned together and also fairly flimsy when looking at a collapsed tooth on the third gear from the left (foreground cluster) above centre line. Nathan.
2 June 2017 at 00:34 #300776
Jeff Dayman
Participant
@jeffdayman43397
A shaper could make those Citroen gears easily, with a good operator. I'd be surprised if Mr Citroen did not build their own special shaping machines for making them.
2 June 2017 at 07:30 #300781
Anonymous
See this thread on herringbone gears:

**LINK**

Andrew
2 June 2017 at 07:45 #300784
clogs
Participant
@clogs
Hi all,

I beleive that Mr Citroen was in engineering before making car's………

and by 1928, my Citroen C4 uses straight cut spur gears….

is this gear box from a truck ?

notice all the oil feed pipes…

clogs
2 June 2017 at 08:00 #300786
Hacksaw
Participant
@hacksaw
Doh… how did i miss that thread ?

Its a headstock i believe
3 June 2017 at 15:49 #300981
Phil Whitley
Participant
@philwhitley94135
I believe Monsieur Citroen actualy bought the patent for the herringbone gears from an impoverished Polish engineer. They were often used in mine winding equipment because the gears were self centering, and could not come out of mesh.
3 June 2017 at 16:07 #300983
Swarf, Mostly!
Participant
@swarfmostly
Posted by Phil Whitley on 03/06/2017 15:49:57:

I believe Monsieur Citroen actualy bought the patent for the herringbone gears from an impoverished Polish engineer. They were often used in mine winding equipment because the gears were self centering, and could not come out of mesh.

Unlike the gears in the original BMC Mini gearbox! They were single helicals and a stack of them were retained on a splined shaft with a nut and lock-tab washer. When the lock-tab washer failed (not a rare event) and the nut loosened, the side thrust caused the gears to slide along the shaft and put the transmission into an illicit neutral.

The only benefit when this happened to me and I got a friend to tow me home was that the car thieves who tried to steal the car that night didn't get very far!

I believe that marine gearboxes use BIG double helicals, some made, once upon a time, by Browns of Manchester (?) on a machine floating on a pool of mercury. (Urban myth??)

Best regards,

Swarf, Mostly!

Edited By Swarf, Mostly! on 03/06/2017 16:08:58

Edited By Swarf, Mostly! on 03/06/2017 16:09:20
3 June 2017 at 17:15 #300997
SillyOldDuffer
Moderator
@sillyoldduffer
Apparently Citroen is the Dutch word for a Lemon. I've driven quite a few lemons in my time, most of them bought when BL were going pear shaped…
3 June 2017 at 18:31 #301009
Carl Wilson 4
Participant
@carlwilson4
So what’s that gearbox from then? I love a nice gearbox. My personal favourite is the product of my namesake, the Wilson pre selector. Originally used I believe on Daimler cars. Later versions could be found in buses and diesel railcars. Listening out for the tell tale hiss as the pneumatic cylinders engaged band brakes to change gear. Also some early diesel loco’s had them.

Wilson’s design was made by SCG or Self Changing Gears. I think they were sometimes known as “pneumo-cyclic”.

Edited By Carl Wilson 4 on 03/06/2017 18:32:47
3 June 2017 at 18:38 #301014
Carl Wilson 4
Participant
@carlwilson4
There you go SCG set up by Walter Gordon Wilson and John Davenport Siddeley. Sorry I don’t mean to hijack this thread….
3 June 2017 at 18:56 #301017
Neil Wyatt
Moderator
@neilwyatt
Posted by Carl Wilson 4 on 03/06/2017 18:31:00:

Later versions could be found in buses and diesel railcars. Listening out for the tell tale hiss as the pneumatic cylinders engaged band brakes to change gear. Also some early diesel loco's had them.

Ah so that was what was behind that characteristic sound of the buses when I was a boy. A 'pshhht' every time it changed gear?

Neil
3 June 2017 at 19:01 #301019
Carl Wilson 4
Participant
@carlwilson4
Yes exactly that. Each gear is selected by operating a band brake. In the later versions of these boxes (as used on buses, railcars and early diesel locomotives) the band brake was engaged by a pneumatic cylinder. Some types used hydraulics.

I remember the hiss on buses and when I used to take diesel railcars from Marylebone out to Wendover in the late 80s too. Those railcars were in their twilight years then.
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