Hydraulic Motor Compatibility

[Train]

Planning on building a power rake for my skid steer and can't seem to find answers of if a certain motor will work. My machine is a Bobcat s130. 16.9 gpm flow rate, with relief valve pressure of 2600. From what I'm finding, the rake I want to build usually runs about 250 rpm. Princess Auto is has a sale on motors with really good pricing, so that's where I'm sourcing from. The only motor that seems close has a max rpm of 304 rpm's, but the pressure rating is only 2320. Now because I don't run my skidsteer at max rpm, would this motor work for me?

 

[oldnslo]

Train
What displacement is the motor you are looking at?

The pressure is determined by load so 2320 PSI would be marginal if you repeatedly load the rake so close to the point of stalling.

 

[Train]

11.9cu in. The next size up is too slow, the next down,375rpm. They both have the same 2320 rating. I don't think the load will be that great. I'd be using it just to smooth some ground around the farm yard, and I've got time to make multiple passes if neccesary.

 

[ptsg]

While the rating on the motor is 2320 PSI, the motors can sustain higher pressure spikes. They often list a max pressure for 30 seconds.

 

[dfkrug]

11.9cu in. The next size up is too slow, the next down,375rpm. They both have the same 2320 rating. I don't think the load will be that great. I'd be using it just to smooth some ground around the farm yard, and I've got time to make multiple passes if neccesary.

You can also set up a cross-port relief valve so you do not exceed 2300psi. That is what I did when I powered my hydraulic chainsaw with my tractor. Most chainsaws limit pressure to 2000psi, and going to relief happens all the time.

 

[oldnslo]

11.9cu in. The next size up is too slow, the next down,375rpm. They both have the same 2320 rating. I don't think the load will be that great. I'd be using it just to smooth some ground around the farm yard, and I've got time to make multiple passes if neccesary.

If I am doing the math correctly your 16.9 GPM would spin 11.9 Cu in motor approx 328 RPM

A 15.6 cu in would get you in the 250 RPM with 16.9 GPM inlet flow

I would probably look at something in the 14 - 15 cu in range to provide desired speed and increased torque

 

[Train]

They have a 15.4, but it's only rated at 233 rpm.

 

[Gordon Gould]

Isn't your 16.9 GPM at full rpm. Assuming a direct drive between motor and pump. A lower rpm would produce a lower flow at a direct ratio. So you came control the flow with your rpm.

gg