Announcement

Collapse
No announcement yet.

Making a rotary vane compressor

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    I was thinking the same. The ones I have had apart have at least been ground. And not only for surface finish but flatness. If the end plates aren't perfectly flat they won't seal to the ends of the vanes correctly. Hopefully it will work. Fingers crossed for you Finno!

    Comment


    • #17
      Some smog pumps off of old cars used them, I believe some modern day superchargers use them (they must be very refined) nothing wrong with building your own just for the experience of it all, your slot smoothness and vane material choice is probably of the utmost important,,,

      My brothers still talk of a hillbilly fix I did years ago, working on my BMW in the winter months - total body restoration with a torpedo heater in a leaky garage at about 8,000 ft+

      The torpedo heater quit working, so I tore into it and found out that the little plastic 4 vane air pump shot craps,,, broke to pieces and would not inject the needed air into the start chamber for combustion, Now I look back and can't really believe im even writing this and telling the truth lol
      But I took what was on hand (Bondo lol) and built a new center piece --- I used grease on the vanes to keep them from sticking to the bondo and also greased up all other area's in a "like size" lid of somekind,,, inserted the vanes into the bondo and let harden !!! they were not even uniformly positioned and looked awful!!!,

      took the whole mess out of it's "mold" and installed it into the unit ---- IT FREAKING WORKED!!!

      it lasted about two months and then shot craps again right when I got the car about completely done....

      Comment


      • #18
        Appearance is not everything. Quite a few ball bearings I have looked at had finishes in the grooves that "looked" rough and scratched, but the bearings were quite good in operation. So obviously the finish was a lot smoother than it appeared to be!
        4357 2773 5647 3671 3645 0087 1276

        CNC machines only go through the motions

        "There's no pleasing these serpents"......Lewis Carroll

        Comment


        • #19
          Originally posted by J Tiers View Post
          Appearance is not everything. Quite a few ball bearings I have looked at had finishes in the grooves that "looked" rough and scratched, but the bearings were quite good in operation. So obviously the finish was a lot smoother than it appeared to be!
          Yeah, that may be, but they don't need to hold an airtight seal...

          And I'm not only talking about surface finish, but actual flatness. Generally lathes don't face too flat in terms of the level required for something like this. They usually produce a somewhat concave surface when facing. I would be setting that end plate on a surface plate and running an indicator over it.

          Comment


          • #20
            All compressors leak, they are not airtight. That's what check valves are for.

            All the compressor part needs to do is to pump a good deal more than it leaks. The less it leaks, of course the better.

            The side seals are indeed the worst for that, since there is no pressure of spring or centrifugal force sealing them. But, it is possible to lap surfaces, so it ought to be do-able to get it reasonably efficient.

            4357 2773 5647 3671 3645 0087 1276

            CNC machines only go through the motions

            "There's no pleasing these serpents"......Lewis Carroll

            Comment


            • #21
              Originally posted by J Tiers View Post
              All compressors leak, they are not airtight. That's what check valves are for.

              All the compressor part needs to do is to pump a good deal more than it leaks. The less it leaks, of course the better.

              The side seals are indeed the worst for that, since there is no pressure of spring or centrifugal force sealing them. But, it is possible to lap surfaces, so it ought to be do-able to get it reasonably efficient.
              Yes, obviously... But a leak on the edges like will probably occur here will likely mean that very little pressure is produced. That's why I mentioned grinding or lapping in my initial post - but Finno noted that he thought the finish was plenty good enough and he won't need it. We shall see. It will be easy enough to fix at any rate, though perhaps a little time consuming. The fact that he's going to be using oil lubrication may work to his benefit there.

              Comment


              • #22
                First and foremost this is merely an experience. Of course I hope it somewhat works but it will not be the end of the world if it does not. I have already learned a great deal over accuracy and setups with this one.
                One of the reasons the finishing of the surfaces is like mirror may be the way the thing operates. It may well be that the finish becomes like that during the use as the vanes are rubbing against the cylinder walls. It all depends on materials, speed, pressure and phase of the moon.
                The lubrication may also help to seal the vanes. There is an oil pump to generate oil pressure that is supposed to push the blades against the cylinder wallls.

                P.S.
                When reading these posts I noticed one member who might be interested to know that three years ago I was cycling around Freiburg, Germany. If You ever visit Germany. Schwartzwald is one of the regions to have a hike, bicycle tour or perhaps just to buy a cuckoo clock.

                Comment


                • #23
                  Making gear pump gears for lubrication system

                  Click image for larger version

Name:	Forumshot1.jpg
Views:	369
Size:	381.2 KB
ID:	1985373 Click image for larger version

Name:	Forumshot2.jpg
Views:	365
Size:	276.6 KB
ID:	1985374 Click image for larger version

Name:	Forumshot3.jpg
Views:	366
Size:	335.3 KB
ID:	1985375 Click image for larger version

Name:	Forumshot4.jpg
Views:	371
Size:	398.5 KB
ID:	1985376

                  Since the vanes of this compressor will be made out of steel, some lubrication is needed.
                  There will be a gear oil pump that forces the oil into the blades and also pushes the vanes against the cylinder walls hydraulically.
                  Two identical precision gears are therefore made.

                  In this video I am using:
                  - Weiler Matador SV (1972) Lathe
                  - Schaublin SV-51 (1955) Milling machine
                  - BS0 Dividing head

                  The video is here

                  Comment


                  • #24
                    Testing the oil pump.

                    Click image for larger version

Name:	Forumshot1.jpg
Views:	338
Size:	267.2 KB
ID:	1988383 Click image for larger version

Name:	Forumshot3.jpg
Views:	332
Size:	269.9 KB
ID:	1988384 Click image for larger version

Name:	Forumshot2.jpg
Views:	334
Size:	427.6 KB
ID:	1988385 Click image for larger version

Name:	Forumshot4.jpg
Views:	330
Size:	396.4 KB
ID:	1988387 Click image for larger version

Name:	00_title.jpg
Views:	335
Size:	412.1 KB
ID:	1988386

                    There are quite some silly animations. Enjoy!

                    In this video I am using:
                    - Weiler Matador SV (1972) Lathe
                    - Solberga (1975) Drill press

                    The video is here

                    Comment


                    • #25
                      I turned off the video because of the cartoon like animations. A waste of my time to have to watch through them. While I do admire the talent to make the animations they are a distraction to the content in my opinion. Are all you videos in this series like this last one? If so I won't waste my time going through them. Just my .02 cents and worth every penny paid for it.
                      Location: The Black Forest in Germany

                      How to become a millionaire: Start out with 10 million and take up machining as a hobby!

                      Comment


                      • #26
                        Originally posted by Black Forest View Post
                        Are all you videos in this series like this last one?
                        Absolutely not. They have even more animal-like animations.

                        We should respect each others time. It is precious and very limited. I like to make these animations and therefore they are in there. However, I have tried to make it easy to skip over them. The videos are divided into sections and then one can choose which parts of the video are worth watching. I try to be accurate on section descriptions.

                        Comment


                        • #27
                          Making the cylinder

                          Click image for larger version

Name:	Forumshot2.jpg
Views:	242
Size:	294.4 KB
ID:	1991026 Click image for larger version

Name:	Forumshot1.jpg
Views:	238
Size:	591.3 KB
ID:	1991027 Click image for larger version

Name:	title_01.jpg
Views:	237
Size:	362.7 KB
ID:	1991028 Click image for larger version

Name:	00_title.jpg
Views:	240
Size:	565.2 KB
ID:	1991029

                          The cylinder of this air compressor must be quite accurate.
                          I am using my Bison 250mm 4-jaw chuck to turn this cylinder.
                          There is a lot of metal removal and problems associated with it.

                          Drilling and tapping holes to the ends of the cylinder.
                          It is a rather simple task but having them in a perfect bolt circles that are aligned between the ends is no more a simple task.
                          Tapping 16 blind holes to 20 millimetre deep M4, that is not a trip in the park either.

                          Warning: These videos contain animations!

                          Part 6 is here

                          Part 7 is here

                          Comment


                          • #28
                            Humm, I actually liked the animated donkey. I found the verbal descriptions a bit too dragged out. But then, that's me and perhaps others may like that too.

                            That looked like a sheet of extra fine sand paper on the mill or drill press table under the end plate. Did you decide to do some lapping after all?
                            Paul A.
                            SE Texas

                            And if you look REAL close at an analog signal,
                            You will find that it has discrete steps.

                            Comment


                            • #29
                              Originally posted by Paul Alciatore View Post
                              Humm, I actually liked the animated donkey. I found the verbal descriptions a bit too dragged out. But then, that's me and perhaps others may like that too.

                              That looked like a sheet of extra fine sand paper on the mill or drill press table under the end plate. Did you decide to do some lapping after all?
                              You have a point in there about the excessive babble vs actual action. Seems I just cannot help myself 😉

                              The sealing surfacess could be lapped for perfect match and thus avoid usage of some sealing compound. I quess I end up using sealing compound (Permatex Form-A-Gasket).

                              After some thought over the sealing of the lamelles it has become clear to me that the lamelles cannot be made really airtight. However, since the pump is so to say flooded with oil which has the same pressure with the compressed air, the oil takes care of sealing. I think this same principle is also used in the Hydrovane pump. The seal between the rotor and the vanes must be tight enough to not to flood the pump too much which could result in hydraulic lock.


                              Comment


                              • #30
                                This time it is the rotor.

                                It is made out of 50 millimetre cold rolled steel.
                                There will be precision turning and eliminating the taper.

                                In this video I am using:
                                - Weiler Matador SV (1972) Lathe

                                In the video I have now:
                                - cut the crap and done machining
                                - chased the donkey to the field while machining

                                There is a different way to straighten the taper in a lathe. This one involves tailstock adjustment but the measuring during the adjustment is not done from the tailstock. Instead, the travel deviation is measured. This gives a spoton result on the first try.

                                The video is hiding here

                                Comment

                                Working...
                                X