Comparison of properties of electromagnetic clutches with ferromagnetic powder and magnetorheological fluid for low frequency control signals
The article presents the results of laboratory tests for the two electromagnetic clutches of controllable: powder clutch and clutch fluid MR. The research was aimed at comparing the opportunities for coupling the power supply conditions in the low-frequency signals of 1 to 5 Hz. The system uses proprietary software written in Visual Studio C#. The program allows for controlled, laboratory power supply ATTEN PPS3205T-3S.
Infrared camera as part of a feedback loop in the MR fluid coupling research
In the paper the laboratory stand for measurements of electromechanical and thermal parameters of the magnetorheological clutch prototype (MR clutch) is presented. The results of thermal measurements of the MR clutch as heating curves are presented. For the measurement system built in which the FLIR A325 thermal imaging camera is part of a feedback loop. Supervises the work of the original software CP&CiCL (control power and camera in close loop) developed by the authors. As examples of the results of measurement for the first mode of the system.
Experimental Characterization of a Permanent Magnet Magnetorheological Clutch for Automotive Applications
In this work a magnetorheological clutch prototype with a permanent magnet is presented and the torque transmitted in several operating configurations is obtained by a specifically designed test bench. The clutch prototype was designed in order to have the possibility to disengage the vacuum pump which operates the power brake in diesel engines continuously. Torque transmission and size specifications were suggested by the specific application. A permanent magnet was used in order to obtain a fail-safe operation and particular attention was focused on materials selection in order to maximize torque transmission in the engaged mode and to minimize power consumption when the clutch is disengaged.Tests were carried out on the test bench, in which electric motors apply the driving and braking torques to the primary and secondary shaft of the clutch; the transmitted torque was measured by a torque-meter at several rotational speeds. Experimental results are discussed in the paper with reference to classical literature models. The experimental tests gave also useful indications on possible improvements in the clutch design, especially regarding the seals, which have to prevent leakages at the working fluid pressure and to keep the friction losses low.Copyright © 2012 by ASME