Hi, I’m looking for some secondhand hydraulic motors. I’ve contacted many hydraulic companies about what I’m looking for and a lot of them have suggested aircraft hydraulic motors because of their lightweight & high RPM capabilities. I’ve attached a description of what I’m planning to do below.

I’m currently designing a flywheel-powered scooter. The flywheel will be mounted on a backpack and worn; the power from the spinning flywheel will then be transferred through to the scooter via two hydraulic motors coupled together.
The motors would need to be small, light and capable of high RPM (12000 +)  It would be highly beneficial if the motors were reversible meaning they could run as a motor or as a pump.  

I’ve put some brief details of what I’m after below:
Hydraulic motor: small, lightweight, power output control on motor & reversible (act as a motor or as a pump)
Maximum power transfer: 15 Hp
RPM range : 1000 to 12000 +  
           
The backpack would contain a small petrol engine, a flywheel and three hydraulic motors. A hydraulic hose would connect the backpack to the hydraulic motor on the scooter. With my current design I think I would need 4 small hydraulic motors although I may be able to only use three.
I plan to use a small petrol engine (1hp) to spin the flywheel (3Kg) up to speed so I would need two hydraulic motors coupled together for that and then transferring the power from the flywheel to the scooter wheel would necessitate using another two hydraulic motors coupled together.
Using reversible hydraulic motors would mean that I could have a regenerative braking system, so when rolling down a hill the hydraulic motors that are coupled together between the scooter wheel and flywheel could reverse and power could be transferred back into the flywheel.

Does anybody know of any hydraulic motors or systems that would do the job?
I would appreciate any advise or help I can get about this project.
My email address is lincoln2457@yahoo.com.au
I can email diagrams and drawing of what I’m planning to do; they may help to explain further.


Thanks for your time

Regards
Lincoln