Variable Diameter Pulley

Hello, Is there any way of simulating a belt drive with a pulley whose
diameter can increase or decrease by means of a motor.
Currently I am not able to do that. Wanted to know whether such a
scenario is supported in SW.
I am using SW2007 with COSMOS Motion.
Thanks

 

The simplest way I can think of to do that is to drive two tapered
sheaves, that are mounted back to front, one atop of the other, with
one belt. As the belt is mechanically pushed along the taper, of the
top pulley, (drive pulley), the speed of the bottom pulley ( driven
pulley), is changed. If you need a sketch of how this simple mechanism
works, e-mail me and I will be happy to make you a sketch.
Incidentally, this principle goes back to Da Vinci, and has been used
extensively ever since. If you would like to see the mechanism first
hand, look under the protective Osher cover of pretty much any
variable speed drill press

G. De Angelis
De Angelis Tool
Valhalla Grafix
www.deangelistool.com
..

 

Basically, develope a model that is exactly what the mechanism is like.
The only thing that may be a problem is to be able to constrain the
face of the belt to a curved-tapered surface. This may work and it may
not? If it doesn't work directly, then there may be some workaround
with dimpler "hidden" parts?

Another apporach may be to develope an equation, based upon the angle
and distance apart of the taper of the two halves of the pulley. I
have seen something similar with a coil spring where the length of the
spring was driven by the result of an equation, then parts of the model
were moved the spring appeared to be moving, (like a real spring) and a
similar technique could possibly work for this.

Hope this helps.

Ed

 

Ed,

I think he is asking about doing this in Cosmos Motion. The only thing
I can think of is to define some kind of functional relationship
between the two sheaves. Don't know if motion can do this kind of
generalized analysis or if Adams is needed.