How to convert gearpump to a motor

[Raka]

Hi All
Im bit new to this. Id like to know if someone can direct me to a site that explain in detail how to convert a hydraulic gear pump to a motor. Someone told me that the only difference between the two is the size of the ports that drain the leakage oil.

Thanks
Theunis

 

[J_J]

There are some pumps that can be used as motors. Here is one below. I don't know about converting just any pump. I would call the manufacturer about the pump you are interested in and maybe they can help you. I don't believe there are any down and dirty tricks to do this. But maybe someone might answer up and say, I have done it.

 

[J_J]

I just got off the phone to Parker, about the conversion. They tell me that it is difficult to convert a pump to a motor, but using a motor as a pump is not to difficult. It has to do with the pressure on the seals.

 

[Raka]

Thanks for helping. I need to visit a hydraulic repairshop next week to buy a variable displacement pump ($$$) Hope they can help me further with this problem also.
I have a load of these gear pumps, seems if they have the slightes bit of wear the system constantly needs to be bled. Pump is on a Massey174 The pump is mounted on the front of the crank and is rather difficult to mount in a way that it sits still, hence the quick wear.

Theunis

 

[dfkrug]

I would like to hear of an actual case where someone has done it, too.

If you are considering a custom application, I recommend buying a new
surplus piston pump, rather than ordering from a hyd shop or catalog. You
can save 90% or more on the cost.

 

[ol'George]

Normally gear pumps are not shorted lived and do not suck air, unless they are really worn and or and the seal/shaft is worn badly.
possibly you have another problem, I'm guessing this is on a front loader application? --really need more info to be of much help, other than what is already been answered for you.

 

[kenstrac]

Thanks for helping. I need to visit a hydraulic repairshop next week to buy a variable displacement pump ($$$) Hope they can help me further with this problem also.
I have a load of these gear pumps, seems if they have the slightes bit of wear the system constantly needs to be bled. Pump is on a Massey174 The pump is mounted on the front of the crank and is rather difficult to mount in a way that it sits still, hence the quick wear.

Theunis

Could the premature wear be caused by misalignment?

 

[vocungmet]

I don't believe there are any down and dirty tricks to do this. But maybe someone might answer up and say, I have done it.

 

[J_J]

Maybe there is an answer there, but I don't read or speak French.

 

[J_J]

Thanks for helping. I need to visit a hydraulic repairshop next week to buy a variable displacement pump ($$$) Hope they can help me further with this problem also.
I have a load of these gear pumps, seems if they have the slightes bit of wear the system constantly needs to be bled. Pump is on a Massey174 The pump is mounted on the front of the crank and is rather difficult to mount in a way that it sits still, hence the quick wear.

Theunis

It would be easy enough to test those pumps, Put both hoses in a reservoir, and start the pump. If it is sucking air, you will see lots of bubbles. To test the pressure output, add a gage, and a gate/needle valve to choke off the fluid flow. Maybe add a relief across the pump to protect it.