Re: Boeing's Electric Taxi Motor

On 19 Aug 2005 16:32:27 -0700, cvairwerks@xxxxxxxxxxxxx wrote in
<1124494347.758490.150520@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>::

>Larry Dighera wrote:
>> On 19 Aug 2005 15:41:47 -0700, cvairwerks@xxxxxxxxxxxxx wrote in
>> <1124491307.940453.144790@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>::
>>
>> >Fixing the drive motor within the fuselage and then
>> >having to transmitt the energy from there to the landing gear, down
>> >the gear leg itself and then tee it to both wheels really drives up the
>> >complexity.
>>
>> If this is the system Boeing is installing:
>>
>> http://www.wheeltug.gi/technology.php
>> http://www.chorusmotors.gi/technology/
>>
>> What makes you think the motor will be installed within the fuselage?
>
>By what they have released to the press, such as the following:
>
>http://www.flightinternational.com/Articles/2005/05/17/197975/Electric+taxi+concept+gets+test-drive+on+Boeing+767.html
>

Thank you for the link. This is interesting information indeed:

To get more torque out of an electric motor, it is necessary to
increase the current handling capabilities of the inverter.
However, this usually requires a larger, more expensive inverter,
not all the capacity of which is usable because of limits on the
total power available. The Meshcon system gets round this by
regulating the voltage required by the inverter at various speeds,
allowing the inverter to deliver all its power at reduced motor
speeds.

Carman says the Meshcon system has been developed specifically for
traction and increased low-speed torque loads, and applications
for which starting torque requirements are higher than the
continual torque requirements. The system uses multi-phase motors
in which the windings are connecting several inverter terminals to
each other, and not the ground. The different connectors act like
different gear rates, and the motor can electronically change
"gears" by operating the inverter at the harmonics of the drive
frequency.

The system therefore uses harmonic drive to essentially fool the
drive electronics into thinking they are operating at a higher
speed. The net benefit is that the motor drive can achieve five
times the torque speed of a similarly sized machine and is
therefore much smaller and lighter.

"We believe the ability to integrate it into a weight-sensitive
application is totally feasible," adds Carman. The demonstration
is not representative of a flight-worthy system, suggesting that
the drive system is being temporarily integrated into the nose
gear bay and undercarriage leg rather than into the fuselage. The
concept dovetails with Boeing's move to a more-electric aircraft
philosophy, as is being pursued with the 787.

Now I am beginning to understand you concern about weight and
complexity.

I wonder if the electric motor could be integrated into the nose wheel
hubs and drive them through ring gear reduction. That might save some
weight and complexity at the expense of completely redesigning the
nose wheels. Alternatively the motor could be mounted at the top of
the gear leg and its shaft directed down between the wheels to a worm
gear. Of course some sort of clutch would be necessary to disengage
the electric drive system during landing I suppose.

.

Relevant Pages

  • Re: hi help me out guys
    ... angular movement of 0.014 degree to linear motion of 1 micron or maybe ... The first uses a conventional motor with a diameter of about ... This gear then drives a ... The smaller part of the gear then drives a similarly made ...
    (sci.electronics.repair)
  • Re: Variable reluctance motor drive?
    ... reluctance motor salvaged from an old PC tape drive. ... Sounds like it could be a Brushless DC Motor (BLDC) and the common is the ... BLDC are quite common in disk and tape drives, ... Each lobe's winding axis is radially oriented ...
    (comp.arch.embedded)
  • Re: Do you think NI can fix my PLL? -- Details
    ... Your brushed DC motor system has magnets attached to the case, a thingy wound with coils attached to the shaft, an amplifier that delivers current to a switch, and a switch that directs that current to the appropriate coils depending on the angle of the shaft with relation to the case. ... I didn't think seriously of attempting a linear drive for this thing simply because PWM drives are the norm, and I didn't want to mess with figuring out commutation logic when I could possibly avoid another case of reinventing the wheel. ... But seriously, isn't using minor loop synthesis and using the drive in it's intended application as a speed servo a suitable way as well? ... One also usually expects that the VCO response, ie., the frequency response of the phase, is not burdened by zeros/poles close to the desired PLL BW, so one can treat it simply as Kvco/s. ...
    (sci.electronics.design)
  • Re: Do you think NI can fix my PLL? -- Details
    ... Your brushed DC motor system has magnets attached to the case, a thingy wound with coils attached to the shaft, an amplifier that delivers current to a switch, and a switch that directs that current to the appropriate coils depending on the angle of the shaft with relation to the case. ... I didn't think seriously of attempting a linear drive for this thing simply because PWM drives are the norm, and I didn't want to mess with figuring out commutation logic when I could possibly avoid another case of reinventing the wheel. ... But seriously, isn't using minor loop synthesis and using the drive in it's intended application as a speed servo a suitable way as well? ... One also usually expects that the VCO response, ie., the frequency response of the phase, is not burdened by zeros/poles close to the desired PLL BW, so one can treat it simply as Kvco/s. ...
    (sci.electronics.design)
  • Re: Anyone ever taken apart a Black Hole spinner motor assembly?
    ... different motor mounted in backbox but without the gear box. ... I touched the leads to the oem motor, ... The shaft in the gear box was bent and had a lot of play. ... The gearmotor assembly bolted right up, ...
    (rec.games.pinball)