Hi Andrew,
Shafts and fixed drivelines require a lot
of alignment and present a unique problem when the motors are fixed to the
frame and not the swing arm. The travel in the rear swing arm will create
different angles on the driveline at different points of travel.
On every bike I have built so far, I have
used a chain drive. It is simple, easy to work with and more tolerant of the
torque. Some folks may not like the chain noise, but if your sprocket alignment
is accurate and use a good roller chain that is properly adjusted, it is very
minimal. A good source of sprockets and chain is the Surplus Center
(www.surpluscenter.com). For a dual
ETEK setup, I would use at least a #40 chain.
Good luck!
Shawn
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Andrew Wowk
Sent: Tuesday, May 23, 2006 10:08
PM
To: ElectricMotorcycles
Subject: [ElectricMotorcycles]
Planetary Gear Reduction with Belt drive
Hello,
I am at the point in my electric motorcycle project where I need to mount the
motors and choose how best to transmit the power to the rear wheel. I am using
two Etek motors which will be mounted horizontally opposed where the battery
covers previously were (the motors will stick out the sides). The motors will
be run at 72 volts while switched in parallel, and half that while in series.
Given the Etek voltage constant (72 rpm/volt) and the diameter of my rear wheel
(26 inches), I want a reduction of atleast 5.5/1, and preferably as much as 6/1
or more. The top speed would not need to exceed 60 mph. The current controller
used will be a 400 amp Curtis with plans to upgrade to a 600 amp Navitas at
some point. The drive system I choose will need to handle a hell of a lot of
torque.
Unfortunately the smallest drive pulley available with the etek shaft bore size
(7/8 inch) looks to be large enough to where the driven pulley would need to be
way too large. At any rate, the smaller the drive pulley the more tension the
belt will need to handle. A possible solution may be to use multiple stage
reduction.
A planetary gear set may offer a 3/1 reduction (though I'm not sure on this
yet). If this is the case, than I would only need 2/1 reduction of the drive to
driven pulley which means I can have a much larger drive pulley and a much
smaller driven pulley with no trouble. I'm now considering automotive planetary
gear sets.
The pulley drive system may be Browning's HPT (high performance timing) drive
line.
Does anyone have any experience with planetary gear sets or tried this before?
Any advise on belt drive systems? One major problem I can forsee is dirt
getting in the planetary gear system. I don't know if pumping it full of grease
would be a good enough seal, so I may need to somehow install seals. Also I
don't know if there is a big difference between industrial timing pulley drive
systems and those used in motorcycles. Any feedback?
Regards,
Andrew
