Dough machine inner workings

[Octavio38]

Hello, I have seen a machine that can round bread dough very easily and dont undestand how the movement is achieved.

Watch these videos please:

http://youtu.be/fFjovsZokcc

http://youtu.be/6gicSTS-nCo?t=13m35s

http://youtu.be/2VF_ipbpgAM?t=4m42s

As you can see, there are 2 drums that turn at the same time, one outer, one inner. The inner drum's movement is what I cant figure out. In my opinion it turns at the same rate and direction as the outer drum, but not only does that, also there is another movement, a "circular" movement around the longest axis, that moves the dough pieces around the edges of the outer drum.

My question is how that circular movement of the inner drum is produced?

 

[JohnRBaker]

I worked 14 years for Baker Perkins, a manufacturer of commercial baking equipment but the only 'dough rounders' we made were what was called 'conical-bed' rounders, as shown here:

Now these were made for larger dough pieces than seen in your videos. In this case the conical-bed rotated at a fairly high speed (a couple a hunderd RPM), and the dough pieces were dropped between the spinning bed and a fixed sprial-trough which wrapped around the conical bed. The conical bed had radial grooves cut in it to facilitate the turning of the dough pieces as they progressed from the high-speed entry point, up the conical-bed until they were fully and properly rounded and discharged at the top at a lower speed. Production rates in the neighborhood of 200 - 240 loaves of bread per minute were pretty typical for the types of bakeries which we developed our machinery for. For example, a typical final mixer could hold 2,000 lbs of dough in one batch:

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[asimpson]

I would guess the inner drum is performing a circular movement relative to the outer drum . Just like would be done forming balls by hand on a table. This could done by compound cam drive or oscillating link and silder. Noise sujests the later. Cam would be smoother..

http://www.youtube.com/watch?v=KRk96GA_GF0

 

[Octavio38]

Hello, thank you both for your answers.

JohnRBaker, we have that particular equipment in my country, but as you say, it is used for loafs of bread. I am trying to copy the european roll making, which starts at only 40 grams. But the dividers/rounders found here are laughable:

http://youtu.be/k2bvzqN6iXo

asimpson, what do you think of this video, would this work?:

http://youtu.be/Tl5N3dX42mE

 

[JohnRBaker]

BTW, the process of 'rounding' a piece of dough is NOT just to get it into something close to a spherical shape but also to impose a kind of 'skin' on the surface of the dough so that as it rises it retains a smooth texture without it creasing or showing what looks like small tears or scars. That's why no matter what sort of mechanism is used that they all depend on forcing the dough piece between either a pair of contra-moving, or stationary and moving, surfaces, surfaces which have been given a certain finish so as to facilitate this 'skinning' effect.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[MikeHalloran]

The machine in the first video clearly uses a fast-spinning inner drum, a slow- spinning perforated drum with cavities in which the dough balls rotate, and a slow moving belt wrapped around the perforated drum, retarding the rotation of the dough balls and eventually carrying them away from the drums. How that produces spheres not cylinders is unclear to me.




Mike Halloran
Pembroke Pines, FL, USA

 

[jlnsol]

Octavio,

The video

http://youtu.be/Tl5N3dX42mE

you refer to will work as long as the two drums rotate exact same speed. For maintenance I would suggest to avoid (rotating) parts inside the drums.

 

[MintJulep]

I would imagine something like

for the rotary motion.

 

[MintJulep]

Use this:

https://www.youtube.com/watch?v=io1JL1U7kUs

but with the elliptical gears rather than the circular ones shown to drive an inner cylinder.

Simple constant speed drive for outer cylinder.

 

[jlnsol]

Octavio,

It can be done by using two conical gears. The smaller gear rotates in a hole in the wall of the outer tube. It has a pin at certain radius R sticking inside the tube which penetrates into a hole in the inner tube. The bigger gear fits around the outer tube. The outer tube is separately continuously driven. While rotating the smaller gears rolls along the bigger gear thereby creating an exact circular movement relative to the outer tube. Diameter of the circle is 2 x R. Which is exactly what you need. The diameter should be narrower than the cavity in the outer drum.
If the bigger gear has also its own drive, than the number of revolutions can be optimised to get the doughballs just ready as they roll over the conveyor belt path and finally fall out.
If you are interested I cam make a video for it.