| The power consumption of centrifugal loads such as fans and pumps accounts for more than one-third of the total electricity consumption in China.Since the centrifugal loads are characterized by a cubic decrease in shaft power when the rotational speed decreases,the installation of a speed regulating device between the motor and the centrifugal load can achieve better energy-saving benefits.Common speed regulating devices mainly include frequency converters,hydraulic couplings,and magnetic couplings.Among them,magnetic coupling is widely used in the industry because of its merits of light load starting,overload protection,and no oil leakage pollution.Existing magnetic couplings are generally discal or cylindrical type.The advantage of discal type magnetic coupling is its short axial length,but its large radial length leads to large rotational inertia and strict requirements for axial runout.Although the cylindrical magnetic coupling is smaller than the discal type magnetic coupling in terms of volume and rotational inertia,the rotor moves a long distance in the axial direction during speed regulation,resulting in a large operating space and low-speed regulation efficiency.To solve the above problems,a Conical Rotor Magnetic Coupler(CRMC)is proposed in this paper,which can effectively improve the speed regulation efficiency while reducing the volume and rotational inertia of the device.In addition,the heat dissipation device for CRMC is designed,which can effectively dissipate the heat generated by the slip speed regulation and ensure the stable and reliable operation of CRMC.The following work has been carried out in this paper around the proposed CRMC :(1)The basic structure and speed regulation principle of CRMC are introduced.The equivalent model of CRMC is established,the magnetic circuit structure of CRMC is analyzed based on the equivalent magnetic circuit method,and the expression of electromagnetic torque is obtained.The loss characteristics and transmission efficiency of CRMC under centrifugal load conditions are analyzed,and the relevant expressions of CRMC loss and transmission efficiency with slip are given.(2)The composition and principle of the CRMC operating system are described,the specific structural parameters of the CRMC are given,a three-dimensional finite element model of the CRMC is established based on the Ansys Maxwell simulation environment,the mechanical characteristics of the CRMC are calculated and analyzed and compared with the theoretical values to verify the correctness of the model built;the maximum value of the eddy current loss in the speed regulation process is obtained by analyzing the eddy current loss of the CRMC,which provides a basis for the analysis of the temperature field.(3)Static and transient performance analysis of the CRMC is carried out to obtain the speed regulation characteristics under centrifugal load conditions,and the results show that it has good energy-saving and high-speed regulation efficiency;a theoretical calculation model of the axial force of the CRMC was established,and the main factors affecting the axial force are given,and the change trend of the axial force during the speed regulation is analyzed.(4)Based on the theory of temperature field analysis,a three-dimensional model of CRMC temperature field analysis was established in Solidworks environment,and a reasonable heat dissipation device is designed;the three-dimensional temperature field analysis is carried out for CRMC without and with the heat dissipation device,and the results show that the heat dissipation device can significantly improve the heat dissipation efficiency of CRMC,the introduction of heat dissipation device reduces the maximum temperature of the permanent magnet from 116 ℃to 68 ℃,ensuring the long-term stable operation of CRMC. |
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