I have a bunch of vibratory feeders from some factory that is being relocated to Mexico.
I tried one, not really knowing how it works. It promptly started vibrating. Amazingly, some rubber parts that were left in it by the previous owners, started traveling UPWARDS on the spiral, as the feeder was vibrating.
I do not really understand this, I would expect that parts would go down on an inclined vibrating surface, but they go UP. What gives? How do they work?
The angle of the flexible parts causes the vibration to have direction, up in the travel direction, down in the opposite direction, like vibrating this /////// (feeds left) versus vibrating this \\\\\\\\ (feeds right).
RogerN
The coeffient of friction is also at work here. How much depends on the 'stickiness' of the rubber to the vibrating surface.
"Phil Kangas" fired this volley in news:k6jjie $hq$ snipped-for-privacy@dont-email.me:
That's not really much of an issue. It'll work with "slippery" parts, too.
It's partly the angle of vibration, and it's partly the vibration cycle, which is "fast" (fast rise time) in the direction you want parts to slip on half of the cycle, and of limited rise time (slow) in the direction you want them to travel on the opposite phase of the cycle.
So the parts are carried a small angle around the tray with the slow vibration, then a fast-rise return pulls the tray out from under them, like ripping the tablecloth off a table with all the settings in place.
When I first started using Vibratory feeders and was trying to design a vibrator to collimate cut wire I found GREAT information by Googling "vibrators". Try that and see what I mean.
That's not even funny.....
Try "vibratory" instead.
Were you looking for images, I am guessing?
Look closely at the suspension on the bowl. Note that when the motor (usually just an electromagnet) pulls the bowl down, the bowl also rotates either CW or CCW when looking at it from above. In operation when the bowl drops the friction on the part is minimum. When the bowl rises the friction is max and the part will move either CW or CCW per the suspension. Art
Pretty simple. The vibration is set up to work in a specific direction, such as making the track bump down and away from the desired direction of travel. Each time the track bumps, the part is advanced relative to the track by its own inertia. So, the whole trick is to make the vibration a bit asymmetric, so the bump back is more sharp than the return to normal.
The ones with helical tracks to make the parts climb out of a conical hopper make a circular bump, it works the same way.
Jon
"shape of chute"? :)
"Mechanized Assembly: Fundamentals of Parts Feeding, Orientation, and Mechanized Assembly" by Boothroyd. Available used for < $20.
I did the controls for resonant operation of vibratory feeders some years back. Used by a governmental organization to make things intended to go 'bang'.
Best regards, Spehro Pefhany
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