Franken track skid steer

[Pickuptrck]

I have a pair of Bobcat 963 skid steer drive motors that need to go onto a track crawler project. Since there is not piston pump or electronics, is there a way to run them off of a normal hydraulic pump? I have a motor spool valve capable of 25GPM and a 26GPM/3000psi gear pump . I know the swash plate was somehow controlled by the piston pump, hopefully there is a spring that made it divert to half throttle or neutral?? Also, these were the 2-speed models. I would imagine I could use a t-union with constant 400psi +/- to lock it in and hope that it locks to low by default. Any ideas before I break something expensive? =) Bobcat lists the piston pumps as a 40GPM from each of 2 pumps, 1 dedicated to each motor and being piston pumps, I imagine they REALLY only delivered about 20-25GPM. I can mess with wheel RPMs later, right now I just want them moving. Schematics to follow once I figure out how to upload. -Thank you in advance

 

[Pickuptrck]

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[Pickuptrck]

Alright, I'll break this into smaller questions. Without the piston pump supplying essentially pilot pressure to the motor swash plate, can it be locked in to either a half throttle or full throttle configuration so the gear pump output flow alone can be used to control the motor RPM?

 

[jerry]

Alright, I'll break this into smaller questions. Without the piston pump supplying essentially pilot pressure to the motor swash plate, can it be locked in to either a half throttle or full throttle configuration so the gear pump output flow alone can be used to control the motor RPM?

Most skidsteer pumps have the swash plate in the piston pump and it controls how much oil each piston can get. If you run the motor from the pump and control the flow to control the speed would probably build a lot of heat.

 

[Pickuptrck]

Most skidsteer pumps have the swash plate in the piston pump and it controls how much oil each piston can get. If you run the motor from the pump and control the flow to control the speed would probably build a lot of heat.

I would control motor speed like any other motor, by using a OC reversible motor spool valve with a throw handle. Unless I'm missing something, that's essentially all a swash plate does but in a closed loop system, If I'm wrong please tell me. From looking at the service photos of the motor, the entire case turns about 15-30 degrees about half way. The disassembly photos show a set of pistons so I assume they are fixed, high pressure fluid comes in on the left hand side of 3-26 B and exits as low pressure on the right. So would that make the 1.5" lines return pressure and the 3/4 line high pressure, with the 1/4" line being pilot pressure to shuttle shift from high to low speed through the control lens in page, 3-28 A? That would mean I could pressure set it to either speed, apply high pressure on the 3/4 the drain with the 1.5, or is that wrong thinking. 3-21 3-22 3-23 3-24 3-25 3-26 3-27 3-28