I'm working with a Rexroth A6V motor, 55cc max. The datasheet is light on the details; I hope someone can help me. Yes, I'll be using this motor to drive an on-road vehicle, don't know which one yet. I haven't read of any serious home-brew hydraulic hybrid projects, maybe this will be the first.

1. What kind of frictional rotation loss can I expect from such a motor? I have a fixed displacement piston motor, and the shaft requires considerable force to turn. Specifically, can I expect this loss to change with motor displacement, and can I overheat the motor by running it at high (but allowable) speeds and no displacement, thereby not allowing the fluid to cool the motor.

2. Is there a drive clutch that's big enough to handle 250lb/ft of torque, yet be light? Something like a starter drive clutch, just a lot bigger. If there is, would I have to have a soft-start system for the motor, or can I just slam the motor against the clutch?

3. What is the classification of an accumulator in a live circuit for the purposes of vehicle safety? I know that all gas cylinders must have protective caps, which the gas end of the accumulator does. What, if anything, will prevent me from driving with a (composite) accumulator? It'll be well mounted, and will have an inertial (collision) switch connected to some kind of safety system.

I hope these questions aren't too stupid.

Thank you!!
Sergey

I believe you can get better answers quicker at one of these forums. A lot of these persons have already built hydraulic drive vehicles.

http://www.hydraulicinnovations.com/forum/index.php

http://www.machinebuilders.net/forum/forum_topics.asp?FID=5&PN=1

This site shows a type of hydraulic hybrid that will probably see real advantages for energy savings.

http://www.hydraulicsonline.net/Flash/Rexroth/1/index2.html

Here's another site I forgot:
http://www.offroadfabnet.com/index.php