OPERATION PRINCIPLE
When no current flows in the magnetic coil, powder is being attached to input drum side by centrifugal force as separate input drum and output drum, so the torque is not transmitted. If coil is excited by electric current, magnetic flux is generated, then torque is transmitted by the friction between powder and working side.
Features
Excitation current and transmitting torque are almost in proportion, also transmitting torque is controlled with wide ranges.
Regardless of slipped rpm, torque is excellently transmitted.
Torque by residual flux is very little and stopping stability is excellent.
It can operate with slipping state, for large capacity cooling with heat.
Take short repair time as it is dry type, so can use it for long time without any adjustment.
It is friction clutch of based on the powder.
Structure
Fig. 1 Operation principle of Powder Clutch
Current Off: When no current is flowed in the excitation coil, clutch is open-state without any torque transmitted, at the moment powder is being attached by the centrifugal force on the outside of powder cap.
Current In: If current is being flowed into the excitation coil, powder become a solid lump by the strong magnetic flux and torque is transmitted. At this moment, if decreasing or increasing the excitation current, the transmitting torque is also decreased or increased.
BRAKE AND CLUTCH SELECTION
How to select the model?
Use it when operated Rewinder or Unwinder.
When unwind with constant tension or first time has strong after that will be weak. You have use Taper Tension. But Control of torque are better use constant torque.
1. In Case of Use Continuous Slip State
In case of used the Tension Controller of Rewinder, Unwinder, or Torque limited in continuous slip state, contious slip power (P) of Brake or Clutch are calculated below method;
Does select the form of clutch that the P of mode (1) are in a allowable limit.
If not enough the thermal capacity by natural air cooling, reference the allowable limit of each item, and select the natural air cooling, external radiation mode, water cooling mode.
In case of use Continuous slip, most of them select the size of slip rate, and torque was related rated torque of clutch. In this case It can select the easy to control range of using torque as added reducing device.
2. Coupling Device
Load torque (less then 50% of motor regular torque are less then load GD2 (less then 5 timer of clutch GD2), if connect frequency less then 10 times/1 hour, motor has selected, and regular output power of motor are designate the revolution of clutch axes.
Reference to fig-4.
Fig-4 Powder clutch motor capacity
BRAKE AND CLUTCH INSTALL
SUGGESTION
1. General Information
Powder clutch is designed so that high speed axis can be linked to input side.
How do you find Input axis and Output axis?
The answer is when fixed one side and turn other side, In this case, if aluminum cooling plate inside cover is rotation, then fixing side are output axis and the other ways is input side. Also, HSC-A mode are that center axis is output axis and installed as bolt is input axis. In case of use opposite way, do as below 1,000rpm. But we don't suggest this way because powder will be damage as torque feature. Brake and Clutch should use horizontal and cannot use vertical way.
Consider of below circumstance
A. In case of Use as any slope or angle,
B. In case of whole thing are revolved,
C. Used at low temperature or any special specifications.
2. Avoid from "Moisture"
If the powder is wet, operation condition is an un-stable. Especially careful, water or oil to be permeated inside. An occasion attached gearbox, complete does oil-sealing cause oil thought the shaft.
3. Be careful "Surface Humidity"
For the continuous operation, the maximum surface temperature shoul be maintained lower than 30 der.C to protect a decrease of endurance.
4. Lifetime of Powder
Lifetime of powder is depending on operating condition, usually you can operated 5,000 - 8,000 hours in allowable slip rate. When replace powder, do it doing disassembly brake & clutch.
5. In Case of Low-Speed Operation (Lower than 15RPM)
When you operate continuously for the tension control, specific of torque is generated. In case of the on-off operation to be accompanied with the revolving and right after applying the electric pressure (voltage), torque operating can be delayed,
Therefore, to avoid it use as followings.
Even though rolling-up has been completed, if appling a week current [5 -10% of rates] continuously, power is not completely parted from the working surface and can protect to get in between and operation delay.
Minimum RPM does 15RPM as speed up. Be careful, because if enhanced rate is increased, the exact torque control is not available due to the mechanical friction of speed-up machine.
6. Normal Speed Operation
Keep always the normal speed operation and perform the preliminary operation before initial starting because of the power being existed inside Brake and Clutch.
7. Torque Trouble Expected When Initial Starting
In case of the preliminary operation is fully, certainly required to prevent a higher torque cased by the maldistribution or moisture, but it is not often trouble.
After exciting OFF, input & output power are revolving. Sometime cooling side does not revolve due to impurities get into the powder by expansion & contraction of heat, but is not often trouble. At that time, you can operate as turn the axe few times after stop condition.
Forced air cooling. Install the air filter, Normally some oil or moisture is included in the pressed air using for the cooling purpose, therefore, use only the filtered & dried air though the filter. Do not use that air not to filter through to protect powder to be damped & defected.
Water cooling.
Install the water drain cock. Long time operation stop can bring about a corrosion by the inner cooling water, therefore, require drain cock for run out the cooling water. When to stop using long time at a cold place, the cooling water can be frozen and broken down the powder brake or clutch.
Install a fill-up tank for provide fresh of water. If no water supply, then water cooling brake & clutch are easy to fire in inside with in short time.
Be careful of the dew. If supply cold water then can be easy to make dew at powder, so make sure supply water temperature should be same temperature as indoor temperature.
Stop supplying water as soon as machine stop.
http://brake21.com/eng/