torque limiter

GA. But perhaps some clarification is in order.

Without any cartons on the conveyor, start the conveyor motor and time how long it takes for the starting current to settle down. That is the time delay that you need.

You must also ensure that the conveyor is unloaded when you start it (under normal conditions). If you try to start the conveyor with cartons on the belt, it will drive the starting current up, and take longer to settle down.

No its not electrical type

Its mechanical type

I will mentione make and type tomorrow

Please suggest if you have any idea or make about torque limiter

Thank you.

hi Tornado,

That torque limiter is

One Position Engagement Ball detent Torque limiter

Taiwan make-Toung sin

and one limit switch is mounted on that to switch off the machine.

Please help me to solve this problem

I don't know of any easy answer for this, but here are some ideas:

1) Some kind of solenoid-operated device that adds force to the torque limiter during the few seconds of start-up, so that it remains engaged;

2) A jackshaft off to the side with a clutch, this whole assembly providing a positive drive to bypass the torque limiter during the start-up period;

3) Another type of torque limiter that can be electrically engeged/disengaged.

I am not particularly satisfied with any of those ideas.

4) Instead of mechanical devices, consider something that measures the current to the drive motor. After a start-up delay, any increase of current above normal shuts off the motor. This possibility seems the best to me.

Hi Tornado,

Give me your mail id

I will send you the details of Torque Limiter

can you please send me details of those solenoid-operated device.

my e-mail id is sandeepplokhande@yahoo.com

Thank you.

I don't know if such a solenoid-controlled torque limiter exists as a manufactured device; that was only an idea based on this principle.

I am familiar with the ball-detent type of torque limiter. We could also try searching something like "solenoid torque limiter", "two-stage torque limiter", "bypass torque limiter", etc.

I think that many if not most VFDs can be programmed with a low cutout current, but with a few seconds of higher current allowed for starting. This seems to me the most advantageous approach. Once the machinery is up and running, motor current is a good surrogate for torque, so this should work well in your situation.

Rather than put email addresses in posts, which might get you lots of spam, you click on the user name and send a protected email via the CR4 system. They have set up that feature quite well.

Thank you

Let me know about two stage torque limiter

even the idea of VFD current control is very well or do you mean that electrical cam?

Please let me know

I tried the Web searches mentioned before, but alas, nothing useful came up. Conceptually it is easy to imagine a torque limiter of your type surrounded by a clutch that engages on startup, but then disengages to allow the limiter to protect the system. Maybe nobody makes such an animal. I don't have good enough shop facilities to do it myself.

That leaves me favoring the VFD approach, which is all electronic.

what about

SEW EURO DRIVE

I am not familiar with the entire SEW Eurodrive line, but I have used them in conveyor designs in the past. In the larger sizes, what I remember is conventional motors with gear reduction. In the smaller sizes, they have a variable-speed design that (as I recall) depends on friction between a motor-driven metal cone and an elastomer follower roller. By moving the position of the motor/cone, the follower turns at various speeds. These may then be reduced by a normal gearbox. The friction feature might serve to protect against over-torque. However, if the machinery gets stuck for a length of time, there might be a flat spot worn into the follower.

In the fish plant where I work, we occasionally have a problem with washdown water getting into the friction area, so that the drive can slip. This is rare, and otherwise these drives seem to work well.