Research On Magnetorheological Fluid Clutch For Vehicle-mounted Power Generation

Magnetorheological fluid is a kind of smart material with magnetorheological effect.It is widely used in the research field of mechanical transmission because of its advantages of large shear yield stress,rapid and reversible reaction,low energy consumption and easy control.Compared with the traditional transmission method,the magnetorheological fluid transmission control is simple and sensitive,and the output torque and the rotational speed of the magnetorheological fluid transmission device are adjusted by changing the excitation current of the coil to change applied magnetic field strength.Not only easy to implement,but also fast response.According to the technical requirements of on-board power generation for the clutch,this paper has studied in the following aspects.The concept,composition and main performance evaluation index of magnetorheological fluid are expounded.According to the theory of magnetorheological fluid transmission,a new type of transmission and heat dissipation structure is designed,and water-cooled magnetorheological fluid clutch is designed and manufactured based on this.The principle and characteristics of its power transmission and heat dissipation are introduced in detail.Based on the theory of electromagnetic theory,the magnetic circuit is designed for the magnetorheological fluid clutch,and the main structure material of the magnetic circuit and the size of main parts of magnetorheological fluid clutch are determined.Electromagnetic field finite element simulation of the designed magnetic circuit is operated using Maxwell.The overall magnetic field distribution of the magnetorheological fluid clutch under different excitation currents is obtained and the overall magnetic field distribution law is analyzed.The magnetorheological fluid working gap magnetic field distribution map is obtained and analyzed.The axial and radial magnetic field distribution of the working gap is also discussed.At the same time,the influencing factors of the magnetic field strength in the working gap are discussed.Based on the principle of magnetorheological fluid speed control system,the mathematical model of magnetorheological fluid transmission speed regulation is established.Based on this,the mathematical model of magnetorheological fluid clutch speed regulation is determined.The PID control strategy is selected,and the three PID parameters are tuned and simulated by genetic algorithm.A test bench for testing the power transmission performance and heat dissipation performance of the water-cooled magnetorheological fluid clutch is built and related experimental research is carried out.The results show that the water-cooled magnetorheological fluid clutch meets the requirements of transmission performance and heat dissipation performance.