Vibrating wheel hub puller - GIF

[Altair]

Vibrating wheel hub puller.




Previously:

Improvised wheel puller - photo
Haul truck wheel hub - photo
Wheel rim straightening machine - GIF
Wheel winch - video
Formula One wheel guns - photo

[WorkerB]

Seeing the heating that’s going on reminded me of something thats always puzzled me.
Leaving aside potential damage to the ‘wanted’ bits, is it more logical to heat the outer component or the inner component of a frozen coaxial apparatus?

Heating the outer component would make it expand (in all directions) making its internal diameter smaller thereby binding even tighter.

Heating the inner component (again expanding in all directions) would increase its outer diameter thereby binding even tighter.

Does anyone have a logical explanation of which is better?

[nova_robotics]

is it more logical to heat the outer component or the inner component of a frozen coaxial apparatus?

I think it's just a perspective issue with the camera. You definitely want to heat the hub and not the spindle.

[olderdan]

I used to repair Salsbury axles on Scimitars and the method which worked every time was to pour two kettles of boiling water over the hub which would then fall of the taper with a couple of blows of a copper mallet. Trick is to expand the hub before the heat gets to the shaft. Hydraulic puller methods can be a bit scary when they let go.

[NeiljohnUK]

I used to repair Salsbury axles on Scimitars and the method which worked every time was to pour two kettles of boiling water over the hub which would then fall of the taper with a couple of blows of a copper mallet. Trick is to expand the hub before the heat gets to the shaft. Hydraulic puller methods can be a bit scary when they let go.

Thankfully I never had to do anything on my Scimi's axles (2x SE5, 1 x SE5a, 1 x SE6) but my 20lb slide-hammer was favoured for other vehicles.

[olderdan]

Thankfully I never had to do anything on my Scimi's axles (2x SE5, 1 x SE5a, 1 x SE6) but my 20lb slide-hammer was favoured for other vehicles.

I owned 1x SE5A, 1xSE5 and a straight 6 Coupe. All had growly diffs so needed rebuilds, quiet as a church mouse afterwards. Also all fitted with Granada 5 speed boxes, great fun to drive but the old Essex is too thirsty these days.

[tonyfoale]

Heating the outer component would make it expand (in all directions) making its internal diameter smaller thereby binding even tighter.

Heating the inner component (again expanding in all directions) would increase its outer diameter thereby binding even tighter.

Does anyone have a logical explanation of which is better?

Heating the outer component makes it expand as you say but its inner diameter expands away from the centre not towards it. If the hole expanded inward and the outside expanded outward as you propose then there would have to be a ring between those two extremes that did not expand. This is not the reality.

Imagine the circumference of the hole, if that circumference expanded then its diameter also has to expand not close up.

Imagine the hub as being a set of concentric rings, each ring will expand such that inner and outer diameters will expand outward, therefore the whole object will expand outward.

So you need to heat the outer part.

I recall asking my school teacher a similar question close to 70 years ago. He was unable to provide an answer.

[katy]

Heating the outer component makes it expand as you say but its inner diameter expands away from the centre not towards it.

Was taught that in grade 7 science class, 1950s

[mklotz]

Heating the outer component makes it expand as you say but its inner diameter expands away from the centre not towards it. If the hole expanded inward and the outside expanded outward as you propose then there would have to be a ring between those two extremes that did not expand. This is not the reality.

As a mathematician* your description really appeals to me. It is the mechanical example of the Intermediate Value Theorem...

https://en.wikipedia.org/wiki/Interm..._value_theorem

from which this quote...

"In mathematical analysis, the intermediate value theorem states that if f is a continuous function whose domain contains the interval [a, b], then it takes on any given value between f (a) and f (b) at some point within the interval."


--
* OK, I'm not really a mathematician. My degrees all say 'physics' on them but, when you study physics, you automatically get deeply involved with mathematics. I enjoy math and have continued learning about it long after leaving school.

[tonyfoale]

Vibrating wheel hub puller.

Am I going blind? I do not see the source of the vibration, that would be the only interesting thing in that video.