The compressor I used for this project is a Danfoss TL4A:
I don’t remember where or when I got it but what I do know is that I got it totally free.
It was hard to open because I had plans on make it work again maybe as
a vacuum pump, so I need to open it up carefully to get as little metal
debris in it as possible and to the best nothing at all.
The top cover:
And with the top cover off it looks like this:
To get the compressor part out from the inside I need to take of the copper tube that is the outgoing tube.
After this I could lift it all out, and then the springs that almost all refrigerator comps use is clearly visible:
The inner part is resting on these 4 springs to make the comp more stable
and more silent when it start, is running and when it stops. In some comps the inner part is instead hanging from 3 springs.
As you might notice so is it unusual clean, there seems to be no oil in
it all. Well there isn’t. The comp had been on the attic for some years
and when I picked it up I discovered that the comp in some strange way
had tipped so that all the oil had leaked out. It was completely empty
when I opened it.
And this is the inner parts:
And this is the electrical contact that connects the inner part trough the comp shell:
The pump system to the lubrication of the entire comp is a smart but still very simple design, as you can se on this picture:
Yes that’s all! The lowest part on the rotor is formed as a cone and
this is submerged in the oil that is in the bottom. When the engine
start and the rotor start to spin the cone will to and the oil will
then be pressed to the cones inner walls and then go upward because of
the slightly increased pressure of oil to the walls because of the
shape. This will lubricate all that’s need to be and this also helps to
cool down the comp. Its because this that the comps shell will get hot
because the oil will flow all over the inner of the shell.
On this pictures you can se where the oil go in and where it gets out:
And how it looks like if you see true this hole:
And these holes at the top:
In the last pic the hole in the middle is used to lubricate and to cool
down the engine its winding and the rest of the compressor. The upper
hole, which is hard to see, is mainly used to lubricate the bearing in
The bolt to remove the engine from the pump system is under the white plastic things:
After the bolts was away I could take away the windings and the entire engine from the pump system:
Well not really the entire engine, the rotor seemed to be really hard
pressed onto the axle and it was impossible to get it off so it just
had to be there:
Ok now we go to the pump system.
This is the front and those bolts won’t be there for long :
This is how it looks under the first cover:
The thing on in the upper part of the pic is the outgoing valve in the
form of a very thin metal plate, which in close up looks like this:
The thick plate above the thinner one is a plate that will stop the
thinner to be bent too much because it then eventually would break.
If we look at the other side we will find another thin plate which is
the suction valve, which take gas from the inside of the comp:
And a close up of that:
Each of these valves covers a little hole which, if you look carefully,
you can se on each opposite side of this thick cover plate.
Under this thick plate is the piston. But since I couldn’t take off the
rotor so is it impossible to take out the piston. But I can ofcuse take
some picture on it :
The goldish tube you can se on the left is the inlet tube thats go
directly to the ingoing valve. The piston is just under 2 cm (0.78”)
wide and about 2 cm long, I forgot to measure it so that was just a
In the back on the piston there is a tiny hole that is used to
lubricate the ball in the middle on the piston and maybe even the wall
between the cylinder and piston:
And this is all that I can take apart. Here is a pic on when it’s all lined up:
As I said before so did I had plans on use it as a vacuum pump so after some minutes it looks like this again:
And it worked, just as it should!
Since I thought that it probably wouldn’t be many people that have seen
a compressor in action with the top cover open, so did I took some
pictures on it. And it has even been a short movie on it running!
:banana: With the top cover on ofcuse.. Nah this time its off
I took some pictures and a movie on how the oil, after it is pumped up,
and will go and lubricate it all and how this would look like. The
movie is when I start the comp and the oil will start to flow. It could
be hard to see so I light it up with a flashlight. Look at the paper
where I light it up, or at the top in the middle of the axle. You could
see the oil hit the white paper, that is around the comp, and see that
it flows downwards.
This paper protection needs to be there because the oil would ofcuse
otherwise go all over the place. Now the oil stay inside the shell of
Here is the movie. It’s about 13 sec long and the file is 4MB large:
And here are a couple of pictures on how the oil moves around when the comps is on and running:
They are large because you won’t be able to se all the details
otherwise, but I compressed them as much as possible. The same is done
with all the other pictures.
These pictures needed to be taken in 1/1000 of a second to capture the oil drops because it all moved so fast.
The oil came from another compressor, i think it is POE oil but i could be wrong about this, this is how the oil looks like:
Well this was the whole project on how a hermetic sealed compressor is
build and how it looks like from the inside of this black shell. And
also how its looks like when it’s running. I hope this all will be to
someone’s satisfaction =)
Copyright © 2004 Henrik Andersson
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