Subject:
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Re: Automatic Transmission
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Newsgroups:
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lugnet.robotics
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Date:
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Wed, 1 Dec 1999 23:07:33 GMT
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Viewed:
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604 times
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In lugnet.robotics, Robert Eddings writes:
>
> I have been working on building an automatic transmission for quite some
> time but have yet to come up with satisfactory solutions. I am looking
> for additional ideas to try. What I consider to be an automatic
> transmission in this case is:
>
> [Drive train defaults to a high speed / low torque gear ratio. When
> resistance on the gear train causes the motor to stall, the drive shaft
> transfers (slips or flips) to another gear train with a lower speed /
> higher torque gear ratio. When the resistance is lowered, the drive
> shaft reverts back to a higher speed / lower torque gear train.]
>
> One experiment used a worm gear that slid along the drive shaft. The
> worm gear first drives the high speed / low torque gear train. The worm
> gear is kept from sliding forward by a collar in front of the worm gear
> that slides freely on the drive shaft and is connected to rubber bands.
> When the resistance to drive the first gear train is greater than the
> resistance caused buy the rubber bands, the worm gear slides forward to
> engage another gear train. This almost works but I can't keep the worm
> gear from binding between the gear trains and causing a stall.
>
> Any ideas or suggestions would be helpful.
I remember seeing a type of automatic transmission built many years ago, using
Meccano (so something similar should be possible with Technic). It used a
swinging 'bob weight' on an arm, driven by an eccentric, and had a second arm
coming off this driving a ratchet mechanism to actually generate the drive. It
would be a bit bulky, but the mass on the arm limited the actual power
delivered, and at light loads the top of the arm swung a long way and
transferred a lot of motion to the output shaft, when the output was loaded,
the weight instead started to move, and the delivered motion slowed down, but
with more actual torque delivered. It was a form of 'CVT' (continuosly
variable transmission), and was mechanically relatively simple.
Best Wishes
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Message is in Reply To:
 | | Automatic Transmission
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| I have been working on building an automatic transmission for quite some time but have yet to come up with satisfactory solutions. I am looking for additional ideas to try. What I consider to be an automatic transmission in this case is: [Drive (...) (25 years ago, 30-Nov-99, to lugnet.robotics)
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