Hydraulic motors w/ undersized pump?

[Borisw37]

What happens if I have a hydraulic pump that can not source the maximum GPM needed for a hydraulic motor (wheel motor). EX: 12GPM pump w/ a 20GPM motor?
A) Will work just fine but will not achieve maximum speed.
B) Will work just fine but will not achieve maximum torque.
C) Will not work, like a pneumatic impact wrench it needs a certain minimum pressure and flow rate to operate.
D) None of the above_______________.

Thank you,

Boris.

 

[aczlan]

The answer is A. It will work just fine but will not achieve maximum speed.

Aaron Z

 

[dfkrug]

You left out the max pressure developed by the pump, and the max pressure that
the motor can handle. Simply put, the pressure put out by the pump will determine
the max torque that the motor will put out. Not volume.

Generally, you want to stay away from your motor's max volume spec due to the
inefficiency at that operating point. You should look at the motor characteristics
shown in your manufacturer's catalog. Charlynn, White, etc all publish nice PDF
catalogs.

So, running a 20GPM (max) motor at 12GPM should work fine at lower than max
motor output speed as long as you don't exceed the pressure rating.

 

[J_J]

The hyd pump is designed to pump a certain amount of fluid using maximum speed of the pump.

It also has a certain pressure limit built in that is called max pressure.

The hyd motor develops the pressure, and will use the available flow to do work. The hyd motor also has limits for pressure before the seals blow.

If the hyd motor develops more pressure than the pump was designed for, something will burst, be it the pump, hose, valve.

 

[glastron23]

yes JJ the pump creates the flow , the pressure comes from the resistance to the flow of oil, be it a motor driving a wheel or a cylinder that is moving a load. The thing that you forgot is that the system MUST have a pressure relief valve to protect the hydraulic system.. the motor will not blow the system apart if it is designed properly...

 

[J_J]

No, I did not forget about the relief valve as in most hyd system there is one or two relief valves per systems as standard design feature.

I believe that about 95 % of all lever type hyd valves have a relief valve.