>> Instructions for making a balanced e-shaft
>>
>> For general information the spline in the clutch
>> disk in the 12A rotary
>> engine is less than a .9" inside diameter.
>>
>> A Mazda e-shaft lobe has approximately a 2.92"
>> diameter. I guess it has
>> about .01" hard casing around it
>>
>> With driveshaft quality steel with a ¼" center
oil
>> hole  make a 1.82"
>> diameter spline with eighteen teeth the desired
>> length of your engine.
>>
>> Make a broach the same as the aforesaid spline
and
>> have it case hardened.
>>
>> Drill out the oil hole in the e-shaft lobe
>> sufficiently to enable pressing
>> the broach through creating interior teeth in the
>> lobe.
>>
>> Also drill holes in bearing size steel (adapters)
>> and press the broach
>> through to place them as desired on the spline in
>> your engine configuration.
>>
>> Weld whatever end type you desire to the
adapters.
>>
>> It is suggested that bearing support be provided
at
>> intermediate housings.
>>
>> In a two and four rotor configuration the lobes
>> would be placed at 0 and 180
>> degrees.
>>
>> In a three rotor configuration the lobes would be
>> placed 120 degrees apart..
>>
>> Kenneth McKenzie
>
>
>
> Kenneth
> Took a look at an e shaft today and find the
bearing
> journals are 1.69" dia. and the OD of the bearing
and
> lobe are almost tangent at one point. So your
1.82" OD
> spline seems way oversize. It would have to be
smaller
> than 1.69" by an amount that would allow for
> sufficient wall thickness in both lobe and
journal.
> I'm suspecting that a broach pressed thru the lobe
> would create a bulging distortion in the thinest
part
> of it's wall. Do you have any thoughts on this?
> regards, Robert

Robert

Thank you for bringing my error to my attention.

The shaft size I intended to suggest is 1.182"  This
is the diameter of the
eccentric and I believe the same size as the front
drive shaft.

It could be smaller as a .9" diameter works in the
!2A clutch.

I believe that using a longer broach will reduce
distortion pressure. or
making two or three in progressive sizes will also
work.

There is also the advantage to the built up e-shaft.
It will allow for the
installation of a stationary gear on both sides of
the rotor.

Thank again

Kenneth McKenzie

Kenneth
Did a little more study of splines and find that 24
pitch is standard. That dictates a shaft diameter of
1.125 with 27 teeth or 1.25 with 30 teeth. Do you
think it feasible to shape internal splines in lobes
using EDM to minimize distortion and stress? Also did
a quick calc of torsion and find a 1" shaft with
active length of 8" will windup about 1 deg under
500#' torque. Don't know what's acceptable or if I
analyzed correctly. What do you think.
regards, Robert


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