Hydraulic Drive

[Frank Pittelli <frank-at-rctankcombat.com>]

If anyone out there knows something about hydraulics, please give me 
your opinion on the use of a hydraulic pump (driven by an EV Warrior) to 
drive hydraulic motors that drive the tracks and cylinders that control 
elevate and rotate.  I know that hydraulics can pack a lot of power into 
a small space, but I'd like to know the tradeoffs with regard to weight 
and battery consumption.

As I see it, one of the benefits of a hydraulic track drive would be 
that it allows the electric motor to operate efficiently (driving in one 
direction without abrupt current changes), while providing a variable 
amount of power to the tracks.  However, I'm not sure if such a hybrid 
approach would actually save space/weight/energy/maintenance/cost as 
compared to an all-electric solution.

All comments and suggestions welcome.

        Frank "Is Fluid Power In Our Future?" Pittelli

PS. Joe Sommer, do you have an estimate for the minimal amount of torque 
needed to drive our tracks competitively?  I know we need about 250 rpms 
at the drive shaft, but I need to know the torque as well to compare 
hydraulic motors.