Talk:Semi-automatic transmission/Archive 1

Automatic to SMG conversion
Can i turn an automatic to SMG gearbox?

I'm a little puzzled. Shouldn't AMT be a kind of Semi-automatic transmission, or they are the same?--Autrio (talk) 06:50, 27 September 2008 (UTC)


 * No you cannot. A SMG gearbox is a manual transmission with a hydraulic actuated clutch pedal. It does not have a torque converter. You may be able to convert a manual to an SMG, but not an automatic to an SMG. Matty (talk) 00:55, 8 April 2009 (UTC)

Electromechanical automated gearbox
This is a text which recapitulates the manual gear box in context of electromechanical automation (not hydraulic). It focuses on the gears which can be combined with anything which can unload the gears, like: single clutch, double clutch, wet clutch, dry clutch (possibly not torque converter).

All gears are always engaged. The larger gear wheels consist of, coaxially from outside to the centre, teeth for the other gear, synchronizer cone, teeth for the dog, and a disk stack to fix the axial position.

On the axis sit the dog and the other synchronizer cone. Both use axial teeth to fix their angle to the axis. And they have a disk stack on the outside. And they have spring loaded latches to lock them axially to the axis in the disengaged position. The latch of dog also needs the latch in the engaged position. A sensor at each axle sends the position to the computer. The computer sends commands to a robotic arm. The arm can move from axis to axis because for the overdrive gears the larger wheel is on the engine axis and for the other gears the larger wheel is on the differential axis. The arm can move along each axis because multiple gears sit on each axis. The arm can move vertically: the up position is used to move to another position, the down position is used to cling to a position with finger 1 and 2. The hand on the arm has a total of 7 fingers. Finger 3 and 4 embrace the disc stack of the synchronizer cone. This finger have matching half discs on their insides.

Finger 5 pulls back the latch. When the ECU has nearly matched the axis and the gear wheel speed, finger 3 and 4 push the synchronizer cone into the synchronizer cone of the gear wheel. The latch does not latch at any other position, thus finger 5 can move to the latch of the dog. Finger 6 and 7 embrace the disk stack on the dog. Finger 5 pulls back the latch of the dog. The synchronizer cone is supposed to make the speed of the dog and the gear wheel match, thus after a while, and hopefully before the oil on the cones is cooked, there is only a small difference in speed between the dog teeth and the gear wheel. The computer then commands finger 6 and 7 to push the dog into the gear. It does so just after one pair of teeth passed so that the next pair of teeth hit each other with full broadside. The latch on the dog snaps into the hole at engaged position. The synchronizer cone is pulled back and its latch snaps into the hole in the disengaged position.

To disengage, the robot grabs the dog, pulls the latch and waits for the dog teeth to disengage (the ECU is responsible for this). Before the next pair of teeth hit each other, the dog is fully pulled away by the robot. Then its latch snaps into the hole in the disengaged position. While the engine speed is adjusted to the next gear, the robotic arm moves to the corresponding position, and then all starts over again.

All in all an automated gear box is a complicated piece. It has the advantage that friction is only important for short durations and thus not much cooling is needed. Depending on the oil temperature the synchronizer cones can be engaged early to speed up shifting. Arnero (talk) 10:41, 10 April 2009 (UTC)

Hall effect sensors
All semiautomaic transmissions use hall effect sensors. Really? I'd like to see that backed up with a citation. I would have put a CN tag there but it would be too easy to find a citation that a certain manufacturer uses hall effect sensors. That doesn't mean all of them do. Rsduhamel (talk) 03:12, 4 October 2009 (UTC)

Engaging Neutral and reverse
For the needs of parking, reversing and neutralizing the transmission, the driver must engage both paddles at once, after this has been accomplished the car will prompt for one of the three options.

I'm sure that is true for some models but the Aston Martin DBS has buttons to do this and the Citroen C4 has a gear stick that engages neutral and reverse. —Preceding unsigned comment added by DavidAlonso (talk • contribs) 15:23, 8 April 2010 (UTC)

Orphaned references in Semi-automatic transmission
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Semi-automatic transmission's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.

Reference named "carpages": From Lamborghini:  From BMW 3 Series (E46): The New M3 CSL. Car pages. Accessed on 2009-07-10. 

I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 18:57, 5 September 2010 (UTC)

More details on operation
The article does not fully describe exact details of its operation.

1. What happens when a car with a semi-automatic transmission brakes to a stop when the transmission is in manual mode (i.e., the driver is expected to upshift and downshift)? Will the car stall if the driver does not shift to neutral? Similarly, will the engine lug/stall if the driver keeps it in too high a gear for a particular speed?

2. While upshifting or downshifting, does the driver keep the accelerator pedal depressed like automatic transmissions? In that case, does engine control take care of controlling fuel injection during the time window the clutch is being hydraulically engaged (so that engine does not rev high under no load or partial load)? —Preceding unsigned comment added by 66.65.27.201 (talk) 02:08, 4 November 2010 (UTC)

History - Ferrari
Wasn't the Valeo transmission in the Mondial the first semi-automatic gearbox Ferrari used (as opposed to the F1-box in the F355)? — Preceding unsigned comment added by 31.149.93.134 (talk) 12:38, 2 June 2015 (UTC)

"Flappy paddle"?
Does anyone actually use this phrase? I thought that was something Jeremy Clarkson came up with as a joke. AnnaGoFast (talk) 02:42, 6 December 2017 (UTC)
 * What else do you call it?
 * Also Clarkson is seen as the Boddy or Ludvigsen of this generation's motoring journalists. Ford help them. Andy Dingley (talk) 10:29, 6 December 2017 (UTC)

History
'According to the Car Crazy episode "Le Mans Museum of the Automobile", the paddle shifter interface could be found as early as 1912 in a Le Mans race car'

Could this be clarified? The 1912 Grand Prix was held in Dieppe; the Le Mans 24 Hour race was first run in 1923. Mr Larrington (talk) 11:57, 28 May 2009 (UTC)


 * The shifter was not a 'paddle shifter', it was a rotary selector on the steering wheel, not terribly different from a column shifter. The car make & model was not identified in the video; the Bollée appears in an unrelated, later segment. The passage really does not belong on this page; I am removing it. XyKyWyKy aka raffriff42 (talk) 03:07, 16 February 2020 (UTC)
 * How did it work? Did it change gear when the control was moved?  Or did it require the usual foot-operated clutch as well? Was this a column shift (and no more) or was it a semi-automatic? Andy Dingley (talk) 11:41, 16 February 2020 (UTC)
 * They 'demonstrated' shifting with a wave of the hand, so it's not clear how it worked from the video... however I was able to determine the make & model: it's a Bollée Type F. From there it was easy to find a citation for the original passage, which I have restored. XyKyWyKy aka raffriff42 (talk) 16:56, 16 February 2020 (UTC)

All previous reference to British cars using the semi automatic Borg & Beck 'manumatic' transmission of the late 1950's has been removed. Brief commensurate reference should be reinserted under the 'semi automatic' category, in chronological order, say after or before 'volkswagen'. Omitting it completely is misleading and erroneous. —Preceding unsigned comment added by 222.152.83.136 (talk) 00:48, 28 December 2009 (UTC)