Application of magnetic particle clutch
magnetic particle clutch has been widely used and developed in speed regulation, control and other systems because of its structural characteristics and working characteristics. Next, it briefly introduces its application in speed regulation system, coiler constant tension system and automobile differential system
1 application of magnetic particle clutch in speed regulation system
in the speed regulation system using magnetic particle clutch, the two basic characteristics of magnetic particle clutch are mainly applied. First, the static characteristics of magnetic particle clutch are used. This is because the change of torque is basically linear with the excitation current. In this way, after the power is supplied by brush in the speed regulation system, the excitation current can be adjusted to accurately control the torque, and the response is rapid, And can show good repeatability. The second is to use the slip characteristics of the magnetic particle clutch, that is, the output torque is only related to the size of the current, and has nothing to do with the speed. Therefore, by adjusting the size of the excitation current, we can not only maintain the constant torque output, but also freely change the torque value, so as to obtain a wider speed regulation range. And when the magnetic particle clutch is made of industrial pure iron with little remanence, the speed regulation range can be between 5% and 100%
2 main technical parameters and characteristics of magnetic particle clutch in elevator speed regulation system
now take 3.7KW four stage variable frequency adjustable speed motor as an example, and compare the main technical parameters of magnetic particle clutch AC motor speed regulation system, as shown in Table 1
it can be seen from table 1 that the magnetic particle separator motor speed regulation system has the advantages of large adjustment range, simple structure, safety and reliability, rapid response, small size, light weight, low price and so on. And because the torque corresponds to a certain current I value and has good repetition performance, torque control can be well realized. When the motor output is loaded, the speed can be accurately controlled
3 magnetic particle clutch in the constant tension system of coiler by quantifying the application of these physical performance index systems
at present, winding systems are widely used in textile, papermaking, printing and other industries, but for general winding systems, with the coiler in the coiling process, its coil diameter is gradually increased, and according to the definition of torque, the relationship between coiling torque M of coiler and tension F and coil diameter D is as follows:
m=f × D/2 (1)
can be obtained from formula (1): when the torque M is constant, the tension f decreases with the continuous increase of coil diameter D, but in the textile, papermaking and printing industries, the tension f is expected to remain constant. Therefore, in order to ensure that the plate tension f remains constant when the coil diameter changes, it is required that the coiling torque must be in dynamic adjustment with the change of coil diameter. Therefore, we must find an actuator to realize the requirement of constant tension
according to the comprehensive consideration of process requirements, economic parts and external dimensions, the magnetic particle clutch is used as the actuator in the constant tension control system of the coiler. This is mainly because there is a linear relationship between the torque transmitted by the magnetic particle clutch and the exciting current. Therefore, the torque can be controlled by changing the magnitude of the exciting current. The control system is as follows:
the coiling tension control system is composed of tension sensor, tension controller and magnetic particle clutch, which can automatically detect and adjust the real-time tension of the coiler during coiling, so as to keep the tension constant. The tension during coiling acts on the tension sensor through the tension detection roller. The tension controller compares and calculates the real-time tension detected by the tension sensor with the set tension, generates a control signal, and drives the magnetic particle clutch to perform tension control
4 application of magnetic particle clutch in automobile differential system
when the automobile is running, the rolling distance of the left and right wheels sometimes is not equal at the same time, such as the inner wheel travel is short when the automobile turns, the air pressure of the left and right wheels is not equal, the tread friction is uneven, the wheel radius caused by the inconsistent load on the two wheels is not equal, the road conditions contacted by the left and right wheels are different, the driving resistance is not equal, and so on. In this way, if the left and right sides of the drive axle are rigidly connected, no matter cornering or straight-line driving, it will cause the wheel to slip and slip on the hoof, resulting in difficult operation through poor parts. Therefore, an inter wheel differential is installed between the left and right wheels of the drive axle to improve the passing parts and operating parts of the vehicle. At present, most differentials are mechanical gear type. The newly designed magnetic powder clutch differential uses magnetic powder as the friction medium, and controls the torque of the left and right wheels through the speed sensor and direction sensor between the wheels. The purpose of differential speed and force is achieved. Here is the structure and mechanism of the magnetic particle clutch differential:
the magnetic particle clutch differential is to install the two half shafts on the left and right wheels respectively, and then evaluate the brightness change of the marked position. The two full turns in the strong level strong disk magnetic particle clutch are turned up, as shown in Figure 4. When the driving bevel gear NL drives the main transmission gear N2 to rotate, the magnetic particle clutch (housing) 6 consolidated on the main transmission gear N2 rotates together. Under the action of excitation current, the magnetic particles form a chain solid state to mesh with the rotating 4 'and 4', and the rotating 4 'and 4' are connected with the half shafts 5 and 5 'to transmit torque to the wheels 7 and 7'. In order to obtain the same torque of the left and right wheels when the car is driving in a straight line, it can be achieved as long as the current on the two full excitation coils remains unchanged. When the car is changing, under the control of the direction sensor, changing the excitation current on 2 or 2 'can obtain the rotating speed and torque changing on the left and right wheels when the car is driving, so as to ensure the driving performance of the car
the magnetic powder clutch designed by using the working characteristics of the magnetic powder clutch is a speed reducer, which gets rid of the transmission working mode and working characteristics of the mechanical differential. Through the control of intelligent technology, the two driving wheels can obtain the changing speed and torque in the transmission of the automobile axle, which provides a more safe and reliable transmission guarantee for improving the passing parts and driving parts of the vehicle, increasing the elimination of backward production capacity and the supervision of projects under construction
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