Is It Better To Use Air Or Water Cooling For The Heat Dissipation Of The Magnetic Powder Clutch/brake?

Magnetic particle clutch and brake is the use of magnetic powder under the electromagnetic effect to transmit torque, with the advantages of linear relationship between excitation current and transmission torque base, fast response speed, simple structure, no impact, no vibration, no noise, no pollution, etc., is a multi-purpose automatic control element with superior performance, widely used in various industries in mechanical loading, braking and tension control of winding and unwinding in the winding system.

The main purpose of magnetic powder clutch/brake heat dissipation: to reduce the temperature of the inside and surface of the magnetic particle clutch/brake, and to improve the service life and performance of the magnetic particle clutch/brake and magnetic particle and work efficiency.

Allowable surface temperature for magnetic particle clutch/brake:
During continuous operation, the surface temperature should be controlled within the limit values shown in the table below. Exceeding the limit value results in a significant reduction in durability. Surface temperature limit of magnetic particle clutch and magnetic particle brake (The ambient temperature of the outer perimeter of the stator and the temperature of the cooling water are based on 30°C. Please use the above limit temperature as a reference scale and be sure to use it within the allowable continuous slip power.
In order to prevent condensation on the magnetic particle brake and brake at night, the temperature difference between water temperature and room temperature should be kept below 10°C. In addition, the allowable continuous slip power recorded in the catalog of magnetic particle brakes is based on water temperature of 30°C and room temperature of 40°C. If it is too cold, it will cause condensation and the magnetic particle will become wet, so please stop it immediately after the operation. At the end of the operation, the time to stop the water supply varies depending on the relationship between room temperature and water temperature, especially if the temperature difference between room and water temperature is about 10°C, please stop it within 5 minutes. In addition, when the magnetic particle clutch or magnetic particle brake is stopped at night, please be sure to stop the water supply by installing a solenoid valve.

The longer the magnetic particle clutch/brake runs, the higher the temperature inside and on the surface of the magnetic particle brake, and the higher the weight of the load, the greater the torque required, the higher the operating frequency, and the faster the magnetic particle is consumed. Note: Magnetic particle clutch brakes generally only rely on two aluminum back covers (self-cooled or air-cooled) or other heat dissipation devices. The most common types of magnetic powder brake heat dissipation are self-cooling, air-cooled and water-cooled, the self-cooling type is by the aluminum shell cover of the magnetic particle brake itself to dissipate heat and the surrounding air flow environment, the air-cooled type relies on the fan to blow away the heat to speed up the clutch heat dissipation, and the water-cooled type relies on water to use the internal and surface temperature of the magnetic particle brake to drop, so as to provide the use and performance of magnetic particle.

Air cooling: (free cooling) Applicable magnetic particle clutch/brake environment and characteristics:
1) Use in a room temperature environment.
2) Model 40KG or less.
3) The rotational speed is below 800 rpm.

In the above cases, natural cooling can be used. If the speed or temperature is slightly higher when in use, add a fan to make the magnetic particle clutch brake dissipate heat faster.

Water-cooled: Applicable magnetic particle clutch/brake environment and characteristics:
1) Use in an environment with relatively high temperature.
2) The model is greater than 40KG or more.
3) The speed is relatively high.

In the above cases, water-cooled can be used. Large models of general manufacturers will do water cooling, if there is no need to use water cooling, do not install water cooling pipe can be used as air cooling.

Effect of magnetic particle selection on the heat dissipation of magnetic particle clutch/brake:
Magnetic powder has oxidation resistance, high heat resistance, good micro-fineness resistance, long life and high durability; Because of the low power consumption, and the use of high heat resistance and reasonable heat dissipation structure, so the allowable connection work, allowable braking power and allowable slip power are high, because of the use of good magnetic powder materials and good fluidity of spherical powder, so it has smooth connection characteristics and outstanding slip characteristics, and the stability of torque is also good.

Precautions for the use of magnetic particle clutch brakes:
1) The special magnetic powder for magnetic powder clutch brake has the characteristics of high magnetic induction intensity, high permeability, low remanence, low coercivity, high Curie point and large transmission torque. And it has good heat resistance, wear resistance, thermal conductivity and chemical stability. In the military, civilian and other fields, it is mainly used for various magnetic particle clutches, magnetic powder brakes and tension controllers with large torque and high slip.
2) After a period of use, the torque of the general magnetic powder will drop down and cannot reach the required tension, so the new magnetic powder must be replaced, so the selection of magnetic powder material is very important. The selection of high-quality magnetic powder can improve ergonomics, prolong the use time, reduce costs, and at the same time can extend the service life of the magnetic particle brake (clutch).
3) If the speed of your machine drops, the rotation distance fluctuates, and the rotor is suddenly stuck when running at the rated excitation current, please consider replacing it with a new magnetic particle.
4) The magnetic particle brake mainly relies on the magnetic powder to transmit torque, and its service life is directly related to the use of magnetic powder. Magnetic powder is a consumable, so its service life directly affects the operation and performance of the entire magnetic powder brake, including the subsequent production work. The service life of magnetic powder is directly affected by the operation time, load, temperature (surface can not exceed 90 degrees Celsius) and frequency of magnetic particle brakes. The longer the operation, the higher the temperature inside and on the surface of the magnetic particle brake, in addition, if the weight of the load is more, the greater the torque required, the higher the operating frequency, and the faster the magnetic particle is consumed.
5) Note: The heat dissipation of the magnetic powder clutch brake generally only relies on two aluminum back covers (self-cooled or air-cooled), or other heat dissipation devices. The most common types of magnetic powder brake heat dissipation are self-cooled, air-cooled and water-cooled, the self-cooled type is composed of the aluminum shell cover of the magnetic powder brake itself to dissipate heat and the surrounding wind flow environment, the air-cooled type relies on the fan to blow away the heat to speed up the clutch heat dissipation, and the water-cooled type relies on water to use the internal and surface temperature drop of the magnetic particle brake, so as to provide the use and performance of the magnetic particle. The main purpose of these three heat dissipation methods is to reduce the temperature of the inside and surface of the magnetic particle clutch brake, and improve the service life and performance of the magnetic particle clutch brake and magnetic particle as well as the working efficiency.
6) In addition, the service life of the magnetic powder brake is directly related to the quality of the magnetic powder itself, the better the quality, the longer the service life of the magnetic powder, the more the performance can be exerted, the worse the quality of the magnetic powder, the service life and performance of course will drop a lot. Under normal circumstances, the use of magnetic powder can reach 6000~8000 hours, provided that there is no overload, cooling in place, torque and slip power are within the rated range.

Magnetic Particle Brake, Magnetic Particle Clutch Selection:
1) Select the model of magnetic particle brake according to the maximum transmission torque value required, the maximum speed is not greater than the use speed of magnetic particle brake, and the use speed of magnetic particle brake and the use torque are inversely proportional.
2) Secondly, according to the maximum slip power to choose, such as the selection of water cooled magnetic powder brake needs to consider whether the specific use environment is allowed, if the highest torque value of the magnetic particle brake can meet the requirements, but the slip power can not meet the requirements, then you need to choose a higher torque slip power value to meet the requirements of the magnetic powder brake, the heating of the magnetic particle brake is also related to the use time, if the use time is very short, as long as a few minutes, then the slip power is not related, If the water-cooled magnetic particle brake does not heat up during use, it can also be cooled without water depending on the specific situation. 

                           
Application range of magnetic particle clutch/brake:
Magnetic particle brake has been widely used in papermaking, printing, plastics, rubber, textile, printing and dyeing, wire and cable, metallurgy, tablet press and other related coiling processing industries in the unwinding and winding tension control, magnetic particle brake in the case of power to form a magnetic powder chain to transmit torque of the new transmission element, mainly composed of internal rotor, outer rotor, excitation coil and magnetic particle.

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