http://www.google.it/search?hl=it&rlz=1T4ADSA_enIT374IT374&q...

Usually:

frizione automatica (aut.) automatic clutch.
[source Hoepli's The Complete Technical Dictionary]

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Note added at 26 mins (2010-07-09 09:03:51 GMT)
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Translations

frizione s.f. (mecc. aut.) (friction) clutch

['frizzionante' - adjective/gerund form (gerund here because it's after the adjective)]

Defintions

frizione s.f. innesto, che serve a trasmettere o a togliare il movimento del motore al meccanismo di trasmissione.
[source Fratelli Fabri, il Piccolo palazzi, Moderno dizionario della lingua italiana ]

clutch n. a mechanism for connecting and disconnecting the engine system in a vehicle.
[source OED]

Translations

automatic clutch (aut.), frizione automatica.
[source Hoepli's The Complete Technical Dictionary]

auto (automatic, as a cycle, opposed to manual) (mach. t. - etc.), automatico.

Examples

1. "A clutch having a centrifugal clutch mechanism coupled in series with a controlled clutch mechanism to provide automatic clutching for starting and ... . " [web source]

2. "For vehicles with automatic clutching mechanisms, learning to drive them could be much easier for the average driver-to-be." [web source]



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Note added at 46 mins (2010-07-09 09:24:24 GMT)
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Web references

1. Wikipedia entry on clutches - English
http://en.wikipedia.org/wiki/Clutch
2.Wikipedia entry on clutches - italiano
http://it.wikipedia.org/wiki/Frizione_(meccanica)

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Note added at 12 hrs (2010-07-09 21:15:43 GMT)
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Explanation why I didn't translate 'auto' as 'self'

I think I need to explain why I didn't translate 'auto' as 'self.' I could not have given myself a confidence level of 4 if I had.

'Self' is part of a reflexive action:
e.g. 'Maria takes good care of herself'

Remember, in this question - we're interested in a:
"sistema di rotazione prevede una valvola idraulica che rende il motoriduttore di rotazione"; i.e. a mechanical system.

Top ten web-search results for 'self-clutching

1. an article on autistic self-clutching pattern
2. a self clutching container closure
3. an article on self-clutching in macaque monkeys
4. self-clutching in autism (again)
5. self-clutching in behavioural development
6. autistic self-clutching pattern of infant monkeys
7. one of William Blake's works - "she soars with her arms for wings, is not self- clutching"
8. a self-clutching mechanism on a tag stacker
9. an Easter prayer - "...but only our self-sufficient, self-clutching"
10. a Wikipedia entry for the idiom 'clutching at straws'

Here is the link, try for yourself:

http://www.google.it/search?hl=it&rlz=1T4ADSA_enIT374IT374&q...