Lasse D

10 Speed Sequential Gearbox with Park and Reverse

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This is a gearbox meant for scale 1:8 cars. It has 10 forward gears, park and reverse.

4_996_gearbox.jpg

See it in action in this video:

For demo purposes I attach a fake engine and a rear section which shows how the driven wheels turn:

4_994_gearbox_components.jpg

These are also included in the building instructions if you want to try for yourself. The instructions are available here: https://brickhub.org/i/594

4_997_gearbox_instructions_full.png

As explained in the video it uses a center differential in order to get just a single reverse gear and a single park "gear". I call it park instead of neutral as the gearbox is locked up when in that gear. Neutral would mean that the rear wheels are free running.

The gear ratios are:

Gear ratios (1 : X):
R: -0.3
P: 0
1: 0.42
2: 0.6
3: 0.9
4: 1.2
5: 1.62
6: 1.8
7: 2.7
8: 3
9: 3.42
10: 3.6

And by changing the final gear, all ratios can be subject to a multiplier of your own choice. And speaking of multipliers. The gearbox has a 3 speed and a 4 speed transmission like those from the Chiron. And earlier version had two 4 speed transmissions. This, however, didn't allow for the Park and Reverse gears. For those to work I needed the following subtractor:

4_999_gearbox_v1.jpg

I don't know how to fit that into a car, so I'm glad that the final design has ratios that actually work. In the video I go through the design process in detail and also give tips to others who want to design their own gearboxes, should they want to follow this approach.

The instructions are in public domain and I will submit it to the gearbox thread:

 

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Wow! This is an amazing gearbox. I've always had the vague notion that it should be possible to use a differential in a gearbox to combine multiple inputs, but I always shied away from doing the math for it.

Even though a 10-speed gearbox is not really realistic I think this is one of the most innovative gearboxes I've seen for some time.:thumbup:

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Thanks for the feedback. Do you really not think that automakers will put 10 speed transmissions into cars eventually? I think putting a 10 speed into something like a Mustang would give it pretty good acceleration - even with the less powerful engines. Or how about a big Luxury Cruiser where 10 speeds could be used to select just the right overdrive gear while cruising down route 500. I think it sounds realistic.

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Ford already uses a 10 speed automatic in a Mustang with the engine at the front and the driven wheels at the rear - as I imagine you already knew ;)

Manual models with complex gearboxes aren't really my bag, but I'm impressed anyway. While the mechanism isn't realistic, it's great that you got 10 actual gears with decent steps between them, in the right order, so at least the effect will be realistic.

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Yeah, I mention the cars in the cars with 10 speed transmissions in the video and point out the Mustang specifically in the description on the instructions page.

You are now the second to point out that it isn't realistic... and I find that criticism a bit baffling. Of course it isn't realistic. I never claimed this to be a scale model. It is a LEGO creation: It is made out of plastic. Gears are straight cut. It uses dog clutches, has a mechanical shifter mechanism and in no way was it claimed to resemble an actual gearbox. It is just like most other LEGO gearboxes, including those in official licensed sets. Real automatic transmissions are made out of metal, have helical gears, consist mainly of planetary gearsets and are computer controlled with either electric or hydraulic brakes on components of the planetary gears in order to create the gear ratios. I mean. See what I had to build in order to create a 39/25 reduction. In real life that gearing would be achieved by using two gears.

4_999_gearbox_v1.jpg

It is like saying that the fake engine isn't realistic because it has a flat plane crank shaft, whereas the real car has a cross pane crank shaft, that there is no camshaft, no starter motor, no oil pump, no fuel injection system, etc.

Is there something that I am missing here?

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@Lasse D it's not specifically a criticism  of your work. Call it Olden Days Syndrome if you like, but I'd rather have the toy teach me something about how the real thing works, rather than just have the same inputs and outputs.

I am equally disappointed that Lego couldn't manage a boxer 6 or W16 engine.

Let's not get started on linear actuators which give a smoother action than pneumatic cylinders, but lose all the simulated realism of a hydraulic system; or too-basic suspension setups (I've not looked into how it works on the Sian, maybe it's better).

Apparently though I'm in the minority, because gearboxes seem to sell well, and none of them in the 1:8 UCS sets have anything to do with reality.

Edited by amorti

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That makes more sense. Thanks for explaining.

I agree that it would be nice with elements that allowed us to recreate the real thing more accurately. Specifically, we need smaller planetary gears. The existing options of Power Miners drill, turn tables and banana gears are not really useable.

The real 10 speed AT in the car I'm building has 4 planetary gears - all in line:

16-12-08-lexus-lc-transmission.jpg

 

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Technic is about problem solving and understanding enough about mechanics to come up with a solution, and thats exactly what this is... so i also find the 'unrealistic' comment baffling. As was mentioned, all engines are totally unrealistic, the suspension in virtually every moc and the UCS sets is not even close (and there's no excuse with suspension..). The gearboxes aren't realistic in any set or moc... but thats because its lego!

Great gearbox!

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On 6/7/2020 at 6:19 AM, Lasse D said:

Thanks for the feedback. Do you really not think that automakers will put 10 speed transmissions into cars eventually? I think putting a 10 speed into something like a Mustang would give it pretty good acceleration - even with the less powerful engines. Or how about a big Luxury Cruiser where 10 speeds could be used to select just the right overdrive gear while cruising down route 500. I think it sounds realistic.

I do believe that the 2020 Ford Expedition has a 10 speed automatic transmission. I assume other cars have a like transmission. 

Also really epic transmission. 

Edited by LegoBuilder919

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Yeah, a number of Ford, GM, and Honda vehicles now use 10-speeds, and I bet other companies do too (Lexus was mentioned above)

I just built the gearbox, and I assume that the working principle is as follows:

The three-speed works like a normal sequential gearbox, but the four-speed subtracts one of four smaller amounts from each of the three speeds. This would seem to create a twelve speed, but because one setup subtracts the same amount that the other gearbox added, causing the output to remain fixed, and another setup causes more to be subtracting on the one side than is added on the other side, creating a reverse.

Does this sound correct?

It's a very neat gearbox!

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32 minutes ago, 2GodBDGlory said:

Да, ряд автомобилей Ford, GM и Honda теперь используют 10 скоростей, и я уверен, что и другие компании тоже (Lexus упоминался выше)

Я только что построил коробку передач, и предполагаю, что принцип работы такой:

Трехступенчатая коробка передач работает как обычная секвентальная коробка передач, но четырехступенчатая вычитает одну из четырех меньших величин из каждой из трех скоростей. Казалось бы, получается двенадцать скоростей, но поскольку одна установка вычитает ту же величину, что и другая коробка передач, в результате чего выходной сигнал остается фиксированным, а другая установка заставляет вычитать больше с одной стороны, чем добавляется с другой стороны, создание реверса.

Это звучит правильно?

Коробка передач очень аккуратная!

Sounds like a gearbox for truck. But there usually 4-gears, demultiplier and multiplier.

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Huh. I did some work last summer with a semi truck driver, and could not make heads nor tails of the sticker explaining which gears were where on the shifter! I'll have to do some research on this, thanks!

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@RazzPinazzo

I couldn't find anything describing such a transmission. I'm quite interested in the concept, though.

Do you know of any resources I could learn about such transmissions from?

Thanks

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Impressive work Lasse D, glad you shared it with us. As someone that is trying to learn more about LEGO gearboxes, I am always interested in what others are accomplishing.

I do think it is funny people cite realism as a reason to not use a ten speed gearbox, still, more and more vehicles in real life are turning to transmissions with far more than just the usual 3 or 4 speeds.

Anyway I like it and thanks, keep up the great work and continue sharing, please. Have a LEGO great day all.

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