2 speed hyd motor plumbing

[cbailey1956]

Hello, In the past I acquired a drive motor from a ASV 100. I know it is a two speed with brake and case drain. I am unsure of how to plumb the motor hydraulics. The case drain and two drive fittings are obvious. The brake and two speed fittings are where I am unsure. I have a recollection the brake circuit can withstand full operating pressure and have purchased a "T" check valve to pressurize the brake release when the motor is operated. The two speed selection port is where I am in uncharted territory. How to select between hi and lo? My intent is to use the motor to drive a screw type wood splitter from my backhoe or modified hough wheel loader that has 25 GPM at operating speed. Backhoe is case 580K with added aux hydraulic valve that operated a breaker. Have flat face connectors in left rear wheelwell. View attachment 442292View attachment 442293View attachment 442294 Thanks for looking, Craig

 

[oldnslo]

What is the model, brand name, etc, shown on the nameplate on the end of the motor in the second picture. This information might help get better answers.

 

[CJONE]

A 2 speed circuit on a Charlynn is just pressure actuated just like your brake circuit. But like Oldnslo stated it would be nice to know what you actually have first. CJ

 

[cbailey1956]

View attachment 442369View attachment 442366View attachment 442366
Here is the data plate off the rear. mostly curious if the 2 speed defaults to high or low if no pressure applies to port. Want to try this motor out and see if performance warrants use. If not will purchase another motor eventually that operates as needed with my flow and psi. This motor should have plenty of grunt to turn the screw in wood. Just unsure of the size and how it will perform with my flow and psi.

 

[oldnslo]

That is a Rexroth MCR 5 radial piston motor brand labeled for Cat. I would be very surprised if the model code follows any published data sheet completely but here are some of the specs that I find. I would suggest doing a search for RE 15198, that is the Rexroth data sheet for this style of motor.

820 cc per rev displacement

250 Bar (3625 PSI) rated operating pressure

Max RPM is 265

Two speed is default to low speed high torque

Brake release pressure: 11 - 15 Bar ( 160 - 218 PSI) with 40 Bar (580 PSI)maximum

hope this helps

 

[MHarryE]

Both brake and shift should be hydro charge pressure. Spring apply hydraulic release parking brake.

 

[cbailey1956]

Thanks for the help. Looks like I need to make a brake release circuit and shift circuit using lower pressures if I understand your responses. Thanks for the help.

 

[oldnslo]

Yes, the brake & 2-speed shift requires a low pressure circuit which like MHarryE states is usually taken from the charge pump on a closed loop HST system.

 

[CJONE]

Thanks for the help. Looks like I need to make a brake release circuit and shift circuit using lower pressures if I understand your responses. Thanks for the help.

Yes, like the others have stated. You can accomplish this with a accumulator, check valve, and a pressure reducing valve if you don't have a low pressure system [either a hydrostat charge pump or a pilot control circuit] You tie into a circuit that has enough pressure to charge the accumulator to a higher pressure than you need then run the reduced pressure to your brake and speed control valves. Just did this with a drilling rig out west. CJ