How does the semi automatic transmission work.

[Philspanner]

Although not a true automatic. Can anyone tell me how the coupling is achieved. I was told it was by wet clutches. I am familiar with torque converters, fluid couplings, electromechanical and mechanical clutches.
My only guess is sintered bronze clutches, similar to the early British Leyland mini and controlled by high frequency solenoid that metered oil pressure, to achieved a slip engagement.
My interest in the subject is purely a need to understanding machines.
Thank you . Phil.

[PMK]

Although not a true automatic. Can anyone tell me how the coupling is achieved. I was told it was by wet clutches. I am familiar with torque converters, fluid couplings, electromechanical and mechanical clutches.
My only guess is sintered bronze clutches, similar to the early British Leyland mini and controlled by high frequency solenoid that metered oil pressure, to achieved a slip engagement.
My interest in the subject is purely a need to understanding machines.
Thank you . Phil.

In simple terms, it is the same clutch as a normal setup. The gearbox is the same also. The clutch is rpm and pressure dependent. The plates are typical friction plates, runs wet and uses a judder spring to smooth the release. The bar mounted shiftlever should be unloading the engine and bumping the shift solenoid to move the shift shaft.

Basically, a really fancy pull rope mini bike or for comparison, similar to an off-road bike with a Rekluse clutch, but the Rekluse maintains the shift lever.

PK

[SNOOPY]

Wow, and I thought some magic was involved.

[bcoulter19]

When I saw the title I was going to say Very well .

[vided]

I think it works real nice.

[gypsy_100]

Here are two posts I put in some time ago. Maybe this will help.

First post:
The SE is not an "automatic" transmission. The transmission is the same as the SM -- a manual transmission with a conventional motorcycle-type multiplate wet clutch. The difference is that BRP designed an automatic clutch control system and shifting system to shift the manual transmission. They also added a centrifugal clutch mechanism to keep the clutch disengaged at idle when not moving. Conventional thinking and experience with "automatic" transmissions does not apply. If you downshift the SE or downshift the SM, you are doing the same thing and with the same results.

Second post:
The clutches for both SM and SE's are essentially the same -- multi-plate wet motorcycle clutches. The centrifugal part of the SE arrangement is a centrifugally actuated mechanism that disengaged the conventional multi-plate clutch when the rev's dropped low such as when you were stopped and the engine is idling. For normal shifting, the clutch operation was not centrifugal but was operated by oil pressure and control solenoids that would quickly disengage the clutch perfectly synchronized with the shifting solenoids to get the next higher or lower gear. The 2014's did away with the centrifugal mechanism for the SE's and use computer programming to gradually engage the clutch from a standstill so you get a smooth start without stalling the engine or without excessive clutch slipping. The same way the automotive "dual clutch" transmissions do.

[Fat Crip]

Actually, and really only if anyone cares, Great Britain is made up of just three countries (Scotland, England and Wales), the United Kingdom adds Northern
Ireland to the mix as United Kingdom is actually short for the United Kingdom of Great Britain and Northern Ireland. Just as well we abbreviate that!

And, of course, on the 18th of next month Scotland (where I live) is holding a referendum to ask whether we should secede from the United Kingdom after 300 years. Hopefully the polls are right and we will vote no, and stay as we are, but watch this space...

I wouldn't have raised this as it's a bit anal, but as it was raised I thought it ought to be correct.


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[Bob Denman]

Thanks!
I hope that however your vote goes; it goes without folks getting too upset over the results.