burntside bob
New member
- Joined
- Jun 14, 2010
- Messages
- 24
I have purchased a White WR255400 hydraulic motor to power a home made rock drill and regulate the down pressure on the drill bit.
The factory representative of Kubota Tractor (the drill will mount to a Kubota mini excavator) said, the diesel engine and hydraulic pump puts out 1475 PSI at the hydraulic motor tool (the white motor) at 17-18 GPM at max engine RPM of 2800 RPM.
If I cut back the engine to 1400 RPM the GPM should drop to 8-9 GPM, this is what I want, for pulling the drill bit out of the hole via steel roller chain on drill mast.
My question is how do I limit the hydraulic force being applied to the drill bit, I mean the hydraulic motor (white WR255400) applying down pressure on the drill bit.
Would a pressure relief valve work placed in the supply line to the WR255400 hydraulic motor?
I want around 400 pounds of force from the WR255400 hyd motor on the drill bit and also (very important) use the 1,000 lb hydraulic force from the WR255400 hyd motor at 1500PSI to pull the drill and drill steel up out of the hole.
What comments and suggestions do you have?
ADDITIONAL COMMENTS: next day posted in reply to questions asked.
In reply to the posts replying to this question:
When drilling into the hole I want, need 400 pounds of down force applied to the drill bit, like placng many many concrete blocks on top of the drill to increase the force of the drill bit hitting the rock, speeding the hole drilling.
When pulling the drill bit out of the hole after the depth has been reached, I want to use all the force/power of the WR225400 hydraulic motor I can get which at 1500 PSI is about 1,000 pounds of force, this 1,000 is after having factored in the 4 inch sprocket wheels of the roller chain drive system powered by the WR255400 motors power. If PSI is reduced to 400 PSI (the factory chart for hyd motor communicates the pulling force is reduced to only 300 pounds of force, too little for my need).
On Duff's comment of using the valve levers to control the hyd oil flow, good comment, but it would result in more or less down pressure then the 400 pounds thrust force I want. Need to do something else then randomly moving the valve lever to different positons, although close to the same location each time a hole is drilled. Away that will consitently repeatably result in 400 pounds down thrust is what I need.
Also I can not reduce the PSI to the WR255400 hyd motor as I need the 1475 PSI from the excavator to get the power to pull the drill up the drill mast and drill steel out of the hole.
Need a way to regulate the down pressure on the drill bit at 1475 PSI to around 400 pounds force on the drill bit.
The Kubota engine is to be run at 1/2 throtle to get around 8 GPM flow, this will result in the WR255400 hydr motor turning the sprocket wheels at 63 times a minute which I need to control the speed of pulling the drill up out of the hole.
The only hydraulics being worked while drilling is the WR255400 hyd motor the rest of the hyd controls are not touched.
I seldom ever open the engine up wide open, don't need the power or all that hyd fluid speed it provides.
On a Pressure Reducer Value would I need a pressure relief valve or something else ?
Thank you for replying to this question, it is much appreciated and very helpfull.
The factory representative of Kubota Tractor (the drill will mount to a Kubota mini excavator) said, the diesel engine and hydraulic pump puts out 1475 PSI at the hydraulic motor tool (the white motor) at 17-18 GPM at max engine RPM of 2800 RPM.
If I cut back the engine to 1400 RPM the GPM should drop to 8-9 GPM, this is what I want, for pulling the drill bit out of the hole via steel roller chain on drill mast.
My question is how do I limit the hydraulic force being applied to the drill bit, I mean the hydraulic motor (white WR255400) applying down pressure on the drill bit.
Would a pressure relief valve work placed in the supply line to the WR255400 hydraulic motor?
I want around 400 pounds of force from the WR255400 hyd motor on the drill bit and also (very important) use the 1,000 lb hydraulic force from the WR255400 hyd motor at 1500PSI to pull the drill and drill steel up out of the hole.
What comments and suggestions do you have?
ADDITIONAL COMMENTS: next day posted in reply to questions asked.
In reply to the posts replying to this question:
When drilling into the hole I want, need 400 pounds of down force applied to the drill bit, like placng many many concrete blocks on top of the drill to increase the force of the drill bit hitting the rock, speeding the hole drilling.
When pulling the drill bit out of the hole after the depth has been reached, I want to use all the force/power of the WR225400 hydraulic motor I can get which at 1500 PSI is about 1,000 pounds of force, this 1,000 is after having factored in the 4 inch sprocket wheels of the roller chain drive system powered by the WR255400 motors power. If PSI is reduced to 400 PSI (the factory chart for hyd motor communicates the pulling force is reduced to only 300 pounds of force, too little for my need).
On Duff's comment of using the valve levers to control the hyd oil flow, good comment, but it would result in more or less down pressure then the 400 pounds thrust force I want. Need to do something else then randomly moving the valve lever to different positons, although close to the same location each time a hole is drilled. Away that will consitently repeatably result in 400 pounds down thrust is what I need.
Also I can not reduce the PSI to the WR255400 hyd motor as I need the 1475 PSI from the excavator to get the power to pull the drill up the drill mast and drill steel out of the hole.
Need a way to regulate the down pressure on the drill bit at 1475 PSI to around 400 pounds force on the drill bit.
The Kubota engine is to be run at 1/2 throtle to get around 8 GPM flow, this will result in the WR255400 hydr motor turning the sprocket wheels at 63 times a minute which I need to control the speed of pulling the drill up out of the hole.
The only hydraulics being worked while drilling is the WR255400 hyd motor the rest of the hyd controls are not touched.
I seldom ever open the engine up wide open, don't need the power or all that hyd fluid speed it provides.
On a Pressure Reducer Value would I need a pressure relief valve or something else ?
Thank you for replying to this question, it is much appreciated and very helpfull.
Last edited: