Runge_Kutta

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United States Patent Application 20030224901
Raghavan, Madhusudan; et al.

December 4, 2003

FAMILY OF SIX-SPEED PLANETARY TRANSMISSIONS HAVING THREE PLANETARY GEARSETS AND THREE INPUT TORQUE-TRANSMITTING MECHANISMS

Abstract

A family of multi-speed planetary transmissions has three planetary
gearsets each with three planetary members and five torque-transmitting
mechanisms. The transmission also has two interconnecting members, one
of which interconnects a member of each of the planetary gearsets, and
the other of which interconnects two members of the planetary gearsets.
All of the transmission family members include one member continuously
connected with a stationary member or transmission housing. In each family
member, the input shaft of the transmission is selectively connectible
with the planetary gearsets through three of the torque-transmitting
mechanisms. The output shaft of the transmission is continuously connected
with at least one member of the planetary gearset. The torque-transmitting
mechanisms are selectively engaged in combinations of two to establish at
least six forward speed ratios and one reverse speed ratio.

Inventors: Raghavan, Madhusudan; (West Bloomfield, MI) ;
Bucknor, Norman Kenneth; (Troy, MI) ; Usoro, Patrick Benedict; (Troy, MI)

General Motors Corporation

Filed: June 4, 2002
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United States Patent Application 20030224898
Bucknor, Norman Kenneth; et al.

December 4, 2003

Family of multi-speed transmission mechanisms having three planetary gearsets and three input torque-transmitting mechanisms

Abstract

A family of transmissions incorporating three planetary gearsets and
five torque-transmitting mechanisms is effective in a powertrain to
produce at least six forward speed ratios and one reverse speed ratio
between a transmission input shaft and a transmission output shaft.
The planetary gearsets each have three planetary gear members in which
two of the planetary gearsets have two members continuously interconnected
and one of those planetary gearsets and the remaining planetary gearset
have two members continuously interconnected. The remaining planetary
gearset has one member continuously connected with the transmission
housing and the transmission output shaft is continuously connected
with at least one member of the planetary gearsets. The planetary
gearsets have members that are selectively interconnected with the
transmission input shaft through three selectively engageable
torque-transmitting mechanisms. One other selectively engageable
torque-transmitting mechanism provides a brake or a clutch element
for the members of the planetary gearsets. A fifth of the selectively
engageable torque transmitting mechanisms provides a brake for the
planetary gearsets. The torque-transmitting mechanisms are engaged in
combinations of two to establish at least six forward speed ratios and
one reverse speed ratio between the transmission input shaft and the
transmission output shaft.

Inventors: Bucknor, Norman Kenneth; (Troy, MI) ;
Raghavan, Madhusudan; (West Bloomfield, MI) ; Usoro, Patrick Benedict; (Troy, MI)

General Motors Corporation

Filed: June 4, 2002

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United States Patent Application 20030224897
Usoro, Patrick Benedict; et al.

December 4, 2003

FAMILY OF MULTI-SPEED POWER TRANSMISSION MECHANISMS HAVING THREE PLANETARY
GEARSETS AND FIVE TORQUE-TRANSMITTING MECHANISMS

Abstract

A family of power transmissions which are utilized in a powertrain include
three planetary gearsets and five torque-transmitting mechanisms. The
torque-transmitting mechanisms are engaged in combinations of three to
provide a reverse drive ratio and six forward speed ratios. The
torque-transmitting mechanisms will include at least four rotating
type torque-transmitting mechanisms and, in some instances, one stationary
type torque-transmitting mechanism. The planetary gearsets are of either
the single pinion type or of the double pinion type of planetary gearsets.

Inventors: Usoro, Patrick Benedict; (Troy, MI) ; Kao, Chi-Kuan; (Troy, MI) ;
Raghavan, Madhusudan; (West Bloomfield, MI)
Correspondence Name and Address:

General Motors Corporation

Filed: May 31, 2002
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These 3 applications follow a long line of GM transmission patents. Though
thse three are about 6-speed automatic transmissions, if you're curious
about 7-, 8-, and 9-speed ATs, look at this:
http://forums.corvetteforum.com/zerothread?id=699595

You can read more about GMs upcoming rear-wheel-drive 6-speed ATs
(X13R, X14R, X15R, and X16R)
http://www.sae.org/automag/techbriefs/12-2002/ (Scroll down to near bottom)
http://media.gm.com/division/2004_pr...rwd_6speed.pdf
http://waw.wardsauto.com/ar/auto_gm_plans_speed/

along with the FWD X22F
http://media.gm.com/division/2004_pr...6speed_fwd.pdf

Butta

Thanks for the great info once again. :cheers:

BuckyThreadkiller

And to think...some people collect stamps.

Runge, you definitely have an interesting hobby there, purusing GM patent apps.

Runge_Kutta

Hobby? Maybe. It takes just a few minutes to search the 2001-2003 database
late on Wednesday nights for the weekly harvest. GM puts out about 10 patents
a week. Usually three or so are interesting.

For a forum like this where we are always speculating about the future, I
think patents are possibly the best binoculars into the future. It's like
listening to a speaker when they are backstage or otherwise off record. There's
no spin, no hype, or no teasing.

The patents on 6-, 7-, 8- and 9-speed ATs are tremendous in number. That and all
of the implementation issus with Displacement-on-Demand (DoD). The bigger
mystery, to my mind, is gasoline direct injection. Another interesting topic
is the work on high-temperature, creep-resistant magnesium alloys destined
for powertrain applications.

I just hope a few people find it interesting. Each time I look to see a
response, I half expect to read someone screaming to have the thread locked
and moved to "off-topic."

I Bin Therbefor

I was upset enough the last time the moderator moved one of your posts to off topic because someone screamed that I emailed the moderator. I believe his action was not well considered. A better action would have been to discipline the screamer.
Having said that, patents are useful but not sufficient. Go back through the history of GM patents and you'll see a lot that never make it to the market because they have been overcome by events. GM seems to start addressing an issue by researching a multitude of solutions and then gradually focusing down to the least expensive. I believe the two cam engine is a good example. Like a lot of folks I thought 2 cams for three valves was a done deal! Espically given the patents GM has on that configuration. Looks now like 1 cam will give the many of the desired effects at much less cost. If they need the last little but, they can always bring back the two cam.
Keep the posts coming. :cheers:

Runge_Kutta

Thanks!