A curious bearing...

[Richard T]

Stripping down a compressor and looking at the conrod, it has a bearing at the crank end of a type that I've not seen before :

I didn't think bearings were supposed to do this, but maybe I've led a sheltered life. The conrod swings quite happily around on the bearing, in any dimension/direction. In practice / when installed, it can't move in the direction I've shown in the pic (top/bottom), but it can twist left/right and the piston twists in the cylinder as a result. If you twist it beyond a certain point, the balls drop out (hence the gap - I did find that one and will put it back !).

Silly question but should this be happening and in which case what is the term for this type of bearing so I can get some new ones ?

In use, the only thing which stops the conrod rotating too far (and having all the bearings fall out) is the bottom of the conrod itself coming up against the web of the crank, which seems a bit sloppy.

The little spike on the bottom bearing-surround appears to be there to splash into the sump and move the oil around.

Thoughts from those more experienced that I would be appreciated !
Richard

 

[mtt.tr]

Its a spherical bearing.

 

[Paul.]

Its just a self aligning ball bearing, quite a common item really

 

[Barking Mat]

Not unusual .... Tom Jones....

 

[Richard T]

Like I said, a sheltered life. Thanks for the feedback everyone. I've worked on motors and drill presses and lathes that have bearings, but all the piston/crank assemblies I've seen have had conventional split ends with bearing shells etc. Now I just need to find some new piston rings.

 

[Shox Dr]

Its just a self aligning ball bearing, quite a common item really

used in this because the machining tolerances will vary wildly. A bearing without such movement wouldn’t last 5mins

 

[Richard T]

OK, that's interesting. But split-shell-type bearings don't allow any movement. Why would you use a ball-bearing in this context ? Not being picky, seriously interested. Lower friction given it's a small motor driving it ? or it's too much effort to try and constrain the piston twisting around, and simpler to let it do its thing given RPM will always be quite low ?

 

[Paul.]

Its as Shox said, manufacturing tolerances can be much lower on the whole job, a cheap Chinese bearing is probably less than a quid to buy especially in the quantities these manufacturers buy them.
We used to use them on conveyor builds amongst other things, the whole job could be fabricated / welded, got rid of the machining processes altogether.

 

[Richard T]

Got it. This is a Broom Wade compressor from the 1960s so I don't think it's "cheap as chips" manufacturing. Although it's a small compressor so probably not done to the same tolerances as some of their larger ones and I can see just being able to slap a bearing in there that will cope with variations would make life a lot simpler.

 

[hermetic]

Like Hitler..............has it got a ball missing?

 

[Shox Dr]

Like Hitler..............has it got a ball missing?

although rare you could lose a ball and still have 2

 

[badabec]

Like Hitler..............has it got a ball missing?

I hear the other is in the Albert Hall

 

[frank horton]

these bearings allow for carp alignment on the cheaper end....
and on big machines where it's diff to line-bore....

 

[500e]

The dipper is to throw the lubricant about & oil everything
Hudson cars were splash lubrication from early 1900s to I think the Hornet (A winning stock car) in the1950s on both strait 6 & 8 cylinder engines, Saab also produced splash lub on some boat engines

 

[grim_d]

Its a spherical bearing.

Semantics but spherical bearings are plain, used in "rose joints".

You also get a hybrid of the two, a non self aligning ball bearing inside a spherical plain bearing.

 

[mtt.tr]

Semantics but spherical bearings are plain, used in "rose joints".

You also get a hybrid of the two, a non self aligning ball bearing inside a spherical plain bearing.

Spherical roller

 

[grim_d]

Spherical roller

Spherical ball bearing.

 

[mtt.tr]

Spherical ball bearing.

This is a self aligning ball bearing.

When i first look i thought it was a spherical roller bearing, which is not a rose joint.

 

[grim_d]

This is a self aligning ball bearing.

When i first look i thought it was a spherical roller bearing, which is not a rose joint.

The op's bearing is a spherical ball bearing also known as a self aligning ball bearing.

Spherical bearings are plain bearings, encountered on rose joints (or rod ends), also known as "pillow balls" when used in Motorsport applications, such as when replacing a compliant rubber bush.

Spherical roller bearings use rollers instead of balls, also known as self aligning roller bearings.

 

[Hopefuldave]

I hear the other is in the Albert Hall

But poor old Goebels must be hydrostatic - no balls at all

Dave H. (the other one)