Finite Element Analysis of SMC Core Magnetic Gear for Vehicle Powertrain Systems

The utilization of gears as intermediary components for power transmission in electric drive systems addresses the insufficiency of electric machines in handling torque loads effectively. Gears, commonly employed in the industry, can be either mechanical or magnetic, allowing for the balanced transfer of torque and speed at specified ratios. The mechanical and electrical actuation of in-vehicle accessories persists both in traditional and next-generation vehicles. Particularly concerning safety and the sustainability of spare part production and supply, various electrical accessories continue to operate at the 12 V level in modern vehicles. In this context, the use of the Lundell alternator (claw pole) also continues in next-generation vehicles. While the mechanical accessories are driven by a belt-pulley system connected to an internal combustion engine in conventional vehicles, in next-generation vehicles, both belt-pulley systems and x-drive by wire are present. The low efficiency and operational costs of belt-pulley power transmission systems necessitate the adoption of more efficient transmission systems. This study focuses on the development of a soft magnetic composite (SMC) core magnetic gear power transmission system that can serve as an alternative to belt-pulley systems in both traditional and next-generation vehicles. In the proposed system, mechanical power transfer to the Lundell alternator is realized through the intended magnetic gear. The gear ratio is determined to ensure a speed of 1800 rpm at the input of the Lundell alternator while the drive system operates at 6000 rpm. To achieve low volume and high efficiency for the proposed magnetic gear, the SMC material is considered, and a comprehensive analysis using the Ansys Maxwell finite element software is conducted. As a result of the analyses, in the magnetic gear designed with a transmission ratio of 3:1, when a torque of 11.7547 Nm is applied to the input shaft, a torque transmission of 35.9806 Nm has been achieved with an efficiency of 84.73% through the output shaft.