Method and device for testing magnetic viscosity of magnetic liquid

Abstract

The invention relates to a method and a device for testing magnetic viscosity of magnetic liquid, and the method comprises the following steps: taking a permanent magnet as a magnetic source, and restricting the continuous adjustment of a magnetic field to adjust a magnetic conductive rotating ring to adjust a radial adjustable gap up and down along a rotating shaft, thereby achieving the regulation of magnetic reluctance and magnetic flux of a magnetic loop; and further adjusting the strength of the magnetic field applied on a magnetic liquid material sample, starting a speed-regulating motor, then driving the magnetic conductive rotating ring to rotate through the rotating shaft, leading the magnetic liquid to be acted by shearing, converting to rotational torque and rotational angular speed, measuring the magnetic flux on the magnetic loop through a magnetic fluxmeter and finally calculating the magnetic viscosity and magnetic flux density according to a formula. The testing device comprises the speed-regulating motor, a torque and rotational speed sensor, the rotating shaft, a non-magnetic centering component, a magnetic conductive stationary ring, the magnetic conductive rotating ring, a permanent magnetic ring and the like, wherein the magnetic conductive stationary ring, the permanent magnetic ring and the magnetic conducive rotting ring form the magnetic loop with a constant gap and the adjustable gap, and the constant gap is used for forming the uniform magnetic field for restricting the material sample and applying the shearing force on the material sample. The method and the device can accurately determine the critical working magnetic field, realize the measurement of the low-temperature magnetic viscosity, and provide a basis for optimal design of devices for sealing, damping vibration attenuation and the like, and has the advantages of no impacts on the temperature of the sample, convenient use, small power consumption and the like.

Description

technical field [0001] The invention relates to a method and device for testing the viscosity of a magnetic liquid material, in particular to a method and a device for testing the magnetization viscosity of a magnetic liquid under the action of magnetic field magnetization. Background technique [0002] Magnetic liquid material is a magnetic solid-liquid two-phase functional material produced by stably dispersing magnetic particles in a certain carrier liquid through a surfactant. Its overall shape, microstructure and viscosity are constrained and controlled by an external magnetic field. It has very broad application prospects in many aspects such as sealing, damping and vibration reduction, electromagnetic filtering, high-quality audio, sensing, and braking. The study of the viscosity characteristics of magnetic liquids in a magnetic field and at different temperatures is particularly important, which is the basis of its applied research. When the external magnetic field ...

AI Technical Summary

Problems solved by technology

On the one hand, it is not convenient to apply a strong magnetic field to the existing viscosity testing equipment. Even if an external magnetic field is applied, some viscometers that rely on gravity cannot be used, because the magnetic force will be greater than the effect of gravity

On the other hand, the common method requires a large amount of liquid samples each time

[0004] Chinese Patent Application Publication No. CN1737531A and Patent Authorization Announcement No. CN2802498Y provide a test method for the apparent viscosity of magnetic liquids that adopts a magnetic fluid-sealed similar magnetic-concentration structure, controlled by increasing or decreasing the number of permanent magnet blocks in the magnetic-concentration structure. The strength of the external confinement magnetic field is added. On the one hand, it is inconvenient to replace the permanent magnet every time. On the other hand, the change of the confinement magnetic field is discontinuous, and the critical working magnetic field cannot be accurately measured. At the same time, the patent does not provide the determination of the working magnetic field strength. method

The measurement method given in the Chinese Patent Authorization Announcement No. CN2099316U is an improvement of the traditional kinematic viscosity test method. Although the permanent magnet is replaced by electromagnetism and the continuous change of the external magnetic field is realized, it is difficult to achieve the same in a long period of time. Maintain a high magnetic field strength, and each test requires a large amount of liquid samples and consumes more power, especially the electromagnetic coil will generate a lot of heat when it is working, it is difficult to control the temperature of the sample to be tested, especially difficult to achieve Determination of Low Temperature Magnetic Viscosity Properties

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