oil pump Copeland/Frascold/Dorin - Refrigeration-Engineer.com forums

**Peter_1** · #1 07-11-2009, 01:17 PM

Does someone have drawings and an explanation of the working principle of the oli pump you commonly sees on Copeland compressors?
The swash plates which rotates +/- 90) when rotation of compressor changes and locks against a pin. The asymmetric inner pumphouseplate is moving then from one side to another and in- and outlet remains always the same. need this to insert in a course.

Same question for the Bitzer oil pumps (or from what's left because they will change now to splash lubrication on most of their compressors)
What is Frascold or Dorin using? I thought Dorin is using the same working principle as Copeland.

narkom · #2 07-11-2009, 02:19 PM

Is it what you need?
http://www.hvacrinfo.com/cope_ae_bulletins/TAE1166.PDF

NoNickName · #3 07-11-2009, 06:24 PM

The asymmetric crown is to make sure the pump is delivering positive displacement when rotating both CCW and CW.

There is a generic exploded view here: http://www.frascold.it/pdf/SPARE/FCAT08-06-V.pdf

If you'd like a more detailed view, drop me a pm on monday

**Peter_1** · #4 08-11-2009, 08:28 AM

To both posters, thanks already for your help which was helpful. I was looking also for a explanation of the working principle. I know how it works but to explain this in plain words isn't that easy. And.. I'm not sure that my explanation is 100% right.

NoNickName · #5 08-11-2009, 09:36 AM

The inner rotor is axially displaced from the out rotor. While rotating, the vanes open on one side of the rotors (volume increasing) where oil suction is, and close on the other side (volume decreasing) where oil discharge is, very much like on rotating vane hermetic compressors.
The out ring, as explained, inverts discharge and suction when the motor is rotating the other way around.

EDIT: I forgot. This type of gear pump is capable of delivering excessive pressure, and this is the reason why a limiting valve is installed, which basicly is a spring with a shutter ball. This valve will tend to close as years pass by, and as the pump wears.

**Peter_1** · #6 09-11-2009, 08:44 AM

NoNickNAme, apparently, the Frascold works the same way as a Copeland.

NoNickName · #7 09-11-2009, 09:43 AM

Quote:

Originally Posted by Peter_1

NoNickNAme, apparently, the Frascold works the same way as a Copeland.

They are all coming from the same design, more than 30 years ago, probably fedder or prestcold.