V-belts as adjustable brake/clutch
V-belts as adjustable brake/clutch
(OP)
I am designing a piece of equipment that will be mounted onto the forks of a forklift. It will pick up a long item horizontally, and either rotate it 180 deg, or take it to a vertical position. What is unusual is that we also want the ability to lift it up, and then let it go to vertical under its own weight (assuming it is picked up off-center). So, a clutch system is one answer. But, I also want to control the amount of friction. It is also beneficial to have the clutch protect the gear motor, as the load is transported by the forklift and so applies some forces back to the motor. Space constraints tend to make a normal electric clutch a much less desirable solution.
What I am thinking about is the idea of using a band-brake type of system by simply connecting the gear motor output to the rotation assembly using a flat belt. Then an an adjustable tensioner pulley in the system can apply as much friction as desired. Band brakes are common on go-carts, which is how I am familiar with them. But I am having a hard time finding sources for flat belt pulleys.
V-belts are obviously better for many applications. but they would seem to be designed for improved grip, and may not be as controllable if I want to use a V-belt system like a band-brake. I suspect that as I adjust the tension on the V-belt, it will tend to go from little friction to not slipping at all very quickly. But, I don't really have the experience to know if this is the case.
Any thoughts on this?
-Joe
What I am thinking about is the idea of using a band-brake type of system by simply connecting the gear motor output to the rotation assembly using a flat belt. Then an an adjustable tensioner pulley in the system can apply as much friction as desired. Band brakes are common on go-carts, which is how I am familiar with them. But I am having a hard time finding sources for flat belt pulleys.
V-belts are obviously better for many applications. but they would seem to be designed for improved grip, and may not be as controllable if I want to use a V-belt system like a band-brake. I suspect that as I adjust the tension on the V-belt, it will tend to go from little friction to not slipping at all very quickly. But, I don't really have the experience to know if this is the case.
Any thoughts on this?
-Joe





RE: V-belts as adjustable brake/clutch
RE: V-belts as adjustable brake/clutch
Where this idea came from, was from my youth, when I recall seeing a mechanism similar to this that was used on a vehicle as a clutch and transmission. It was a trike-type vehicle at a mission oriented school called the "Southern Institute for Appropriate Technology" in Alabama. The vehicle was designed to be something that could be hacked by local people in less developed countries. The motor rotated a shaft with 3 small pulleys of different sizes, and each of them had a belt that went to a pulley on the shaft that drove the front wheel. Each belt had a lever, and by pulling one of the levers, you would engage one of the "gears".
-Joe
RE: V-belts as adjustable brake/clutch
Ted
RE: V-belts as adjustable brake/clutch
RE: V-belts as adjustable brake/clutch
I know that flat belt brakes are common on go-carts, so perhaps a flat belt system would be a better choice. But, flat belts and pulleys are not that common in the catalogs I have looked at, and there are only a few choices.
-Joe
RE: V-belts as adjustable brake/clutch
-Joe
RE: V-belts as adjustable brake/clutch
je suis charlie
RE: V-belts as adjustable brake/clutch
Walt
RE: V-belts as adjustable brake/clutch
Ted
RE: V-belts as adjustable brake/clutch
But, all ideas are still on the table. If we do end up trying a belt tensioner as means of doing a controlled release for the pivot, then I will report back if it is successful.
-Joe