need Variable displacement gear pump theory

[heavenly]

Hi,
I need details of Variable displacement gear pump like theory,net links,material spects etc

thanks in before

john

 

[hydromech]

You're gunna struggle to find a variable displacement gear pump...other than changing the input speed...?


Does it have to be a gear pump?

 

[heavenly]

Hi Hydromech
thanx for ur quick reply
Yes,particularly we need gear pump only

thanx
nagaraj

 

[hydromech]

I dont know of any suppliers of variable gear pumps, not for 3000 PSI anyway.

The are some lube pumps that vary the flow by sliding the gears to vary the contact ratio between the teeth, but these are all low pressure and 8000 RPM is very high speed...

Sorry I can't help more, good luck with your search.

 

[budt]

Have you searched Google?


Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com

http://www.fluidpower1.us

 

[budt]

Taje a look at this offering.

http://www.uark.edu/ua/techip/techa....pdf#search="variable displacement gear pump"

Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com

http://www.fluidpower1.us

 

[EdDanzer]

Could you use a geroter pump?

 

[WWO]

There is no such thing as a variable displacement gear pump. It is impossible to change the geometry of the gears or that of their centerline relationship to the gear housing, therefore it is impossible to vary a gear pump's displacement.

However, some gear pump assemblies are manufactured with "load sensing" capability. This seems to imply variable displacement, but in reality it does not. A "load sensing" gear pump has incorported into it's outlet side (or attached to its outlet side) a "load sensing" flow control valve (similar to the LS flow dividers used for steering circuits). The load sense signal controls the spool of this flow control valve and the spool, in turn, diverts flow exiting the gear pump so that the actuator attached to the load receives the flow rate called for by the control orifice.

Bill O'Donnell

 

[kcj]

Well explained.
the 'load sensing' also usually varies the relief valve/unloading flow control setting such that the excess flow is not dumping at full relief setting.

kcj