View Single Post
  #5   Spotlight this post!  
Unread 05-09-2007, 11:28
Qbranch Qbranch is offline
wow college goes fast.
AKA: Alex
FRC #1024 (Kil-A-Bytes)
Team Role: Alumni
 
Join Date: Apr 2006
Rookie Year: 2006
Location: Indianapolis
Posts: 1,174
Qbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond reputeQbranch has a reputation beyond repute
Re: Interesting speed reducer mechanism

Quote:
Originally Posted by dtengineering View Post
It would also have to magnify torque in inverse proportion to the reduction in speed... or else give off a LOT of heat. This is because power = torque x rpm. If you reduce the input speed without increasing the output torque, then you have a whole bunch of power that has nowhere to go... which leaves me wondering a bit about their claim of "constant torque across the speed range".... this must require changes in the speed and/or torque on the input shaft.
Isnt that true only if the input and output shafts are constantly connected? What I think happens in this transmission is that the output shaft is, in a manner of speaking, periodically engaged and disengaged in small increments from the input shaft, and depending on where you put the lever, it changes how much of the time the shaft is disengaged. Something like a Pulse Width Modulator in hardware.

As with electrical PWM, though there is less power output (due to lower duty cycle) there is no loss, since instead of doing resistive (linear) control of the output, we're just engaging/disengaging from the power source in varying ratios... weather the power source be an input torque or an input voltage source.

Anybody else?

-q
__________________
Electrical Engineer Illini
1024 | Programmer '06, '07, '08 | Driver '08