How to design a gearbox book recommendations?

[middy]

I'm looking for a book about how to design a gearbox. I did a quick Google search and this was the only one that came up:

Amazon.com: Manual Gearbox Design (9780750604178): Stokes: Books

Unfortunately, that book doesn't have any customer reviews so I'm not sure whether it'd be a good buy and the price is a bit steep, isn't it? Has anyone read that book and if so, is it any good?

Are there anymore such books that you recommend?

Thanks.

 

[Brian Kissel]

I haven't read it, but it was published 18 years ago. I am sure it has all the basics, but technology sure has advanced a lot since then. I'll stick to the Ricardo.

Regards Brian

 

[John]

I have that book. It is VERY technical and goes into a lot of detail as to all of calculations needed to design a gearbox (loads, fatigue, etc). It is short on diagrams but makes up for it with equations. It was written by an F1 gearbox designer. While technology has advanced since then regarding materials, I doubt much has changed regarding the physics.

I think the book is worth the money if you are serious about gearbox design - it's not like there are lot of alternatives out there.

Oddly enough, I recently lent it to a friend who works at Ricardo

 

[Andy Green]

Alex Stokes was Chief Engineer at BRM for transmissions, before joining Lotus Engineering in a similiar position. He always claimed that designing a transmission using the calculations as defined in his book, the transmission would not fail. I worked with him whilst at Lotus to turn his hand calculations into a computer programme (this is now going back 20+ yrs :thumbsup: ).

As previously mentioned the basics of transmission design haven't changed, only the materials & processes are improved, so as a good grounding in transmission design I don't think you'll find a better book

Regards
Andy

 

[middy]

Many thanks for the reviews. :thumbsup:

Cheers.

 

[middy]

I finally got the book last week. It is a good book, I've not read everything yet but however there is one thing that I'm not sure I understand :

(pg 144)
by using the following formula the overall gear ratio, both crown wheel and pinion, and the internal gear ratio, can be calculated as follows:

Overall gear ratio

= Road speed (mph) x 36 x 1760
Engine (rpm) x 60 x 2π x Tyre rolling radius​

Using a ratio of 1:1 for the highest internal ratio, the calculated overall ratio becomes the crown wheel and pinion ratio

If I take a 2004 GT3 as an example, the calculation is as follows: (I assume the tyre radius is in inches)

190 (mph) x 36 x 1760
7400 (rpm) x 60 x 2π x 13​

Answer = 0.33

The cwp ratio of the GT3 is 3.44:1 (31/9), which is nothing like 0.33, isn't it? Please enlighten me. :huh:

 

[Seymour Snerd]

I finally got the book last week. It is a good book, I've not read everything yet but however there is one thing that I'm not sure I understand :



If I take a 2004 GT3 as an example, the calculation is as follows: (I assume the tyre radius is in inches)

190 (mph) x 36 x 1760
7400 (rpm) x 60 x 2π x 13​

Answer = 0.33

The cwp ratio of the GT3 is 3.44:1 (31/9), which is nothing like 0.33, isn't it? Please enlighten me. :huh:

9/31 is 0.29, which is close.

Remember, that calculation assumes the transmission gear ratio is 1:1. If your example car were in an overdrive top gear when the mph and rpm were measured, you would not get the right answer. If that is the case and the car's top gear is about 0.88 (.29/.33) then the formula is correct and all is right with the world. So, what gear was the GT3 in (or assumed to be in) and what is the transmission ratio of that gear? My research indicates 6th gear in a Porsche GT-3 is 0.92 which is close enough to explain the discrepancy given you are estimating tire radius.

 

[Dave Bilyk]

croc,
the attached will help you see,
where the numbers in the equation are from,
that the 0.33 is the overall (gearbox x cwp) ratio,
and how to get the gearbox ratio from the information given.


regards
Dave

 

[middy]

Thanks guys for the clarification.

The 6th gear ratio in the GT3 is 0.86, so the formula is very accurate indeed.
The book even explains the differences between Gleason, Klingelnberg and Oerlikon. :thumbsup: