> > > I was always under the impression that the eccentric shaft rotated
three (3)
 > > > times for every 360 degree turn of the rotor.  That would be a ratio
of 3:1
 > > > not 3:2
 > > >
 > >
 > > Me too. That is why I am confused when Mazda says it is 3:2
 > > I think it has to do with the fact that the rotor is also rotating
 > > and one rotor face completes 360 degrees while the shaft rotates
 > > three times. The gear ratios is still 3:2 as there would not
 > > be enough room around the e-shaft for a stationary gear that
 > > was roughly only 1.16 inches in diameter. That is the stationary gear
size
 > > required if the gear ratio was really 3:1. The pitch diameter of the
rotor
 > > gear is about 3-1/2 inches in diameter. The main bearing alone on
 > > the e-shaft is about 1.7 inches in diameter.
 > >
 > >

 vance wrote:
 >
 > The Ratio between the teeth count is undoubtedly 3 to 2, and this action
 > is not unlike differential tooth count gearing - ie the rotor makes
 > 1/3rd turn (the difference in number of teeth) for each trip around the
 > stationary gear - while the geometric center of the rotor describes a
 > full turn driving the eccentric. In the previous discussion about rotor
 > torque - the stationary gear teeth act as lever points while the torque
 > on the rotor sort of pries the eccentric around. - Vance

 If nothing else the Wankel is hard to explain is it not ? :-)

Dont forget that the e-shaft is not directly attached to any of these gears.
The stationary gears are... stationary.  The gear ratio only plays an
indirect role in the rotation ratio of the e-shaft and rotor.  Someone above
has it right.  3:1 for e-shaft:rotor, which is different from e-shaft:crank
angle sensor.

My crank angle sensor has more than 4 teeth... !?

Dave Leonard

See the above messages from me and Tracy about computers.

Paul Lamar
 
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