Variable displacement oil pump 1

[murpia]

I saw a press release on the new Porsche turbo and one of the new technologies listed was a variable displacement oil pump to reduce parasitic torque at high rpms.

I Googled a bit but could not find any info on how it works. There is mention of axially displacing gears in the press release.

Can anyone explain it to me?

Thanks, Ian

 

[Pancholin]

If I remember correctly the SlimJim Hydromatic had a variable displacement pump.

 

[vagman2]

Yeah, VAG group is using that kind of pum extensively in their small engines like 1.4L FSI/TfSI/TSI etc..

Think this could explain to you:

http://www.volkspage.net/technik/ssp/ssp/SSP_296_d1.pdf

 

[TDIMeister]

There are a couple of variations. The ones I know of (from working at a Tier-1 engine oil- and transmission pump supplier) are of the vane or gerotor type where the eccentricity between inner and outer elements are varied using a hydraulic feedback and a pressure control valve. More eccentricity greater flow/pressure and vice versa. The center rotor is usually fixed and is the driving element while the outer is allowed to move about a pivot axis.

 

[TDIMeister]

I've done work for the pumps in the GM 6T70 / Ford 6F, Audi 2.7/3.0 V6 TDI, VW DQ500, Audi DL501, etc., at various stages of their development.

 

[tbuelna]

murpia,

Take a look at US patent 7,544,052. It gives a good description of how the Porsche gear pump varies output flow. It employs a solenoid control valve and axial displacement of one of the pump gears.

Hope that helps.
Terry

 

[JayMaechtlen]

At least some of the single-coupling Hydramatic transmissions (very early 50's) had variable displacement front pumps. The vane housing slid to vary the displacement. It could fail, jam at full displacement, and prevent upshift from 2nd to 3rd.
I found out later, after going to different powertrain and giving the Hyrdamatics to someone else.


Jay Maechtlen

http://www.laserpubs.com/techcomm