Structure and working principle

The magnetic powder clutch is composed of active rotor(input shaft), driven rotor (output shaft) and Yoke with excitation coil. The three parts are resembled against the concentric part and form a system which can rotate relatively. The annular gap between active rotor and driven rotors is full of alloy powder which has high permeability.

The magnetic powder will be in the state of loose when the current do not pass the excitation coil. The magnetic powder will be thrown on the inner wall of active rotor. In this case, there will not exist the interaction force between the active and driven rotor. Because the magnetic powder clutch is in the state of separation, no torque transmission exists.

The magnetic powder in the working chamber will link in a link state under the action of the magnetic flux generated from the Yoke when the current pass the excitation coil. The magnetic powder clutch can transfer torque relying on the shear force generated from magnetic chain and the friction generated from the magnetic powder and working face. in this case, the magnetic powder clutch is in the state of combination.

When the current is cut off, the magnetic flux will disappear with the disappearance of the magnetizing current, the magnetic powder will be in the state of loose under the action of gravity again, and will be thrown on the inner wall of active rotor under the action of the centrifugal force. In this case, the magnetic powder clutch will be in the state of separation again.

The magnetic powder clutch and brake have the same principle; the magnetic powder brake will form as long as the driven rotor of the magnetic powder clutch is fixed.

Features

The magnetizing current has a relationship with torque

The transmission torque has a linear relationship with the magnetizing current. The size of the torque can get controlled within larger range. Under normal circumstance, the magnetizing current has a linear relationship with transitive torque within range of 5%-100% rated torque.

Stable slip torque

The slip rotational speed between driven rotor and active rotor do not affect the transitive torque when the magnetizing current retain constant. That is to say, the static friction torque and the dynamic friction torque have no difference. Therefore, the torque can retain constant stably. The featuers are applied to tension control, users can control the tension of the roll material effectively as long as regulating the magnetizing current accurately.

Prevention of the phenomenon of heat since slip

The friction part will generate heat inevitably or even destroyed when it keep continuous sliding. But this device has a complete cooling set, it will not generate a lot of heat after long time running and it has a long service life.

Notes

 Don’t overload, meanwhile cool to appropriate temperature

The value of the torque/rotational speed/slip power should be less than the rated value. The cooling mode(natural cooling/forced air cooling/water cooling) should depend on the maximum slip power when it works and the cooling air should pass the water and oil filter. The temperature detector and the alarm should be installed to prevent high temperature which can affect the service life of the magnetic powder.(the highest temperature is 80 degree)

Concerning the service life

The life of the magnetic powder clutch and brake rely on the life of the magnetic powder. Generally speaking, its service life is 4500-7500hours in the state of non overloaded; but its service life can extend several times in some cases, such as: the working torque of the magnetic powder clutch/brake,relative slip rotational speed and slip power can be reduced to 50%-70% of the rated value. This is to say, the margin can be enlarged as soon as possible when designing.

Concerning the torque

After the magnetic powder clutch and brake working, the magnetic powder will be in grinding at the beginning which leads to the torque decreasing slightly, but the gap can be compensated through adjustment the current.

Product superiority

1. CNC precision manufacturing, high accuracy, fine machining , good linearity, and superior performance.
2. Magnetic powder purity, without black toner, stable performance, and long life.
3. Aluminum alloy structure, excellent thermal performance, good demagnetization, fast response.
4. Smooth running, no vibration, no impact, no noise when in  starting, running, braking state.

Application

Specification