Hydraulic Motor Help

[HainesNYT]

Calling out to the GS to see if there are any hydraulic motor geniuses.

I bought a Bradco BC72 rotary cutter (72” shredder) for a skid steer. Got it used at an auction, missing the hydraulic motor. So, this is where things get fun...It was originally built as high-flow unit, but I need to convert it to a low/standard flow unit. Most of it’s life will likely be spent on a New Holland L185: 3,000PSI, 19.3 GPM.

I contacted Bradco and they weren’t very helpful. Not to interested in helping me solve this problem. Bradco told me that it wasn’t just the hydraulic motor that was different. I have found and downloaded the entire parts manual for both the high and low flow models. They have two different gear boxes...Omni Gear RC-61 and RC-51, the 61 on the high flow, the 51 on the low flow. Well, I assumed they were going to be different gear ratios; however, that is not the case! They both run a 1:1.93 ratio and they both have 1 3/8, smooth input shafts, with half inch roll pins. So, all I can tell is that the 61 (on the deck I have) has a higher horsepower rating then the other one.

I have found the Bradco part number for the original high flow motor (17.9cu.i.) and the Bradco part number for the Standard flow motor (10 cu.i.). I did contact a company that sells Bradco parts and they wanted a pretty ridiculous amount of money for their low flow motor. What I cannot get are the specs for the low flow motor, other than the 10 cubic inches.

I contacted Surplus Center and tried explaining and getting assistance on this...yeah, not so much. They wanted engineering specs that I couldn’t even begin to give them. Apparently, I foolishly thought they have sold similar motors for other rotary cutters before.

I have tried contacting other manufactures of skid steer mounted shredders, simply to get brand and part number of the motors they use and prices if they will sell their motors...only one has helped. This places uses a Parker TG0140AS030BBBC (8.6cu.i.) on their 72” cutter. This one has a smaller tapered output shaft and will not mate to the coupler that I have.

1. Does anyone use or own a similar rotary cutter? If so, I would LOVE to know the brand and numbers on the motor, please.
2. Does anyone have any advice on who to talk to that would know about these? My local ag shop is in over their head with these questions.

What I think I know:
a. I need a Hydraulic motor in the 10 cubic inch range
b. needs to be low flow/standard flow compatible, for a 19.3GPM machine
c. *to mate to the coupler I already have, I THINK it needs to be 1 3/8 shaft with a 3/8 key (I may very well be wrong about this...really hoping one of you know what I’m talking about)

This is a photo of the Gear box and coupler I have.
Thanks in advance to anyone who can help.

[HainesNYT]

Ttt

[HainesNYT]

Ttt

[HainesNYT]

Ttt

[caa4612]

I can help you with this. I don't have time tonight to figure up what you need, but I'll try and take a look at this tomorrow.

[caa4612]

So here's the low down. The 10 CID motor will spin faster but produce less torque than the 17.9 CID motor. Either motor won't have an effect on HP. HP in hydraulics is flow and pressure. The torque is pressure and motor displacement X the gear reduction (1:1.93) The other thing to consider is the type of mount you need. Do you have a 2 bolt or 4 bolt mount? Also, what is the pilot diameter of the motor? The pilot diameter is the round part on the shaft side of the motor that would fit concentric once you "stab" the motor into its mount. I sell hydraulics for a living so I live in this world everyday and could help with what you need. I looked up the omni gear and the RC-51 has the 1:1.93 reduction but the RC-61 doesn't so I'd assume you have the RC-51. Also, the RC-51 has a max torque rating of 4667 in-lbs. The 10 CID motor with 3000 psi will give you 4700 in-lbs. With that being said, you will want a 10 CID motor. If you agree with this I can help you find the motor you need.

[HainesNYT]

That's awesome. I really appreciate you taking the time to explain it in depth. I am busy, out of town in a job this week...I would like to pick your brain a little further next week. Again, thanks a bunch.

[HainesNYT]

So here's the low down. The 10 CID motor will spin faster but produce less torque than the 17.9 CID motor. Either motor won't have an effect on HP. HP in hydraulics is flow and pressure. The torque is pressure and motor displacement X the gear reduction (1:1.93) The other thing to consider is the type of mount you need. Do you have a 2 bolt or 4 bolt mount? Also, what is the pilot diameter of the motor? The pilot diameter is the round part on the shaft side of the motor that would fit concentric once you "stab" the motor into its mount. I sell hydraulics for a living so I live in this world everyday and could help with what you need. I looked up the omni gear and the RC-51 has the 1:1.93 reduction but the RC-61 doesn't so I'd assume you have the RC-51. Also, the RC-51 has a max torque rating of 4667 in-lbs. The 10 CID motor with 3000 psi will give you 4700 in-lbs. With that being said, you will want a 10 CID motor. If you agree with this I can help you find the motor you need.

It's been a longtime, but I finally got around to putting this thing together...using your info and what I think I have learned from others. I have a two bolt mount, 10 CID, PTO drive motor from Surplus Center. I also bought a cushion valve (this I have questions about). I fabricated the mount and it fits concentrically, plumbed it, and the thing seems to work well. I was under the impression that the cushion valve would let the shredder "coast" to a stop after the flow was terminated; however, it seems to work more like a brake. It brings the blades/blade carrier down to a fairly quick stop. Is that correct, or do I need to adjust something or rearrange my hoses?

Thanks for the assistance.

Oh, and my gear box is a RC-61. I hope the torque specs are higher on it.

[HainesNYT]

[HainesNYT]

[HainesNYT]

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[yanta61]

Nice....Wish i had one, I wonder if the rent these out?

[HainesNYT]

Nice....Wish i had one, I wonder if the rent these out?

Yes, there are places that rent them. There are several different types available ...some meant to run along the ground more, with wheels or rollers; and extreme duty ones that will cut much larger trees.

[dclifton]

If you ever need any hydraulic motors or valves for ag stuff, look up baileys hydraulics.
Very good people and good prices on Ag Fluid power equipment.

[HainesNYT]

If you ever need any hydraulic motors or valves for ag stuff, look up baileys hydraulics.
Very good people and good prices on Ag Fluid power equipment.

Thanks brother, I am familiar with them. I bought a Chief hydraulic cylinder from them almost 2 years ago. The thing just failed the other day. I called them last week and it had a 3 year warranty on it ....the new one just showed up on the door step today.....ironic