Clutch Slippage detection
Clutch Slippage detection
(OP)
Hi Guys
I've got a machine with 3 * 37kW motors driven from one VSD driving one gear wheel, Each motor has an Individual MCB and an AB E3 O/L for protection, also before the gearbox is a fluid filled clutch. We tried to detect clutch slippage using proxies but they were not quick enough to detect an speed changes so we decided to compare currents from the E3....still this is not good enough anyone with ideas on how to this in code will be much appreciated.
I've got a machine with 3 * 37kW motors driven from one VSD driving one gear wheel, Each motor has an Individual MCB and an AB E3 O/L for protection, also before the gearbox is a fluid filled clutch. We tried to detect clutch slippage using proxies but they were not quick enough to detect an speed changes so we decided to compare currents from the E3....still this is not good enough anyone with ideas on how to this in code will be much appreciated.





RE: Clutch Slippage detection
Hope that helps, Mike L.
RE: Clutch Slippage detection
RE: Clutch Slippage detection
I use this technique to measure slip in induction motors, belt transmissions and such things. Works very well.
Other technique is to put 3M reflex tape on the shafts and use a hand-held tachometer to measure the speeds.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Clutch Slippage detection
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RE: Clutch Slippage detection
1. E3's are not accurate for frequencies less than 20HZ
2. Idea of using proxy switches has failed, they are too slow to pick up the speed differences
3. We still need to confirm the calibration of the curent measurement....compare to a known source
4. Try to use the S-Curve to monitor rate of change in the AB PF700 VFD
5. Use torque sensor for Torque monitoring eg (FUTEK)
more comments are welcome.
RE: Clutch Slippage detection
I have used this technique to measure slips below 0.1 percent.
Did you really try it?
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Clutch Slippage detection
RE: Clutch Slippage detection
http://www.pepperl-fuchs.com/global/en/13577.htm
This is a slip monitoring relay that uses normal inductive sensors to detect slip. This relay has alot of parameters that can be changed to make sure that it meets your requirements. It's easy to setup and it has digital outputs that can be read by a PLC. It can handle high rpm and the sensitivity can be adjusted easily.
Kind regards
RE: Clutch Slippage detection
RE: Clutch Slippage detection
P= V*I*cos(phi) I thought that both would pick up the imbalances.
RE: Clutch Slippage detection
Simply put, because cos(phi) changes a lot more than current when load changes. The reason, simply put again, is that the magnetizing current is more or less constant and masks the change in active, torque-producing) current.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.