Configuration synthesis and screening method for magnetic gear two-speed transmission for electric vehicles

Magnetic field modulated gears have contactless, lubrication-free and highly flexible transmission characteristics, which provide an inherent technological advantage in solving the vibration, jerk and lubrication problems of two-gear transmissions in electric vehicles. To this end, a magnetic gear two-speed transmission drive concept is proposed, and a configuration preference method for two-speed transmissions based on weighted directed topology maps is investigated. A directed weighted graph modulo adjacency matrix and topological evolution rules describing the structure of the system are established. Adjacency matrix ergodic evolution and isomorphism discrimination are investigated for single and two-stage magnetic gear two-speed transmissions, respectively. Through the constructed relative speed link identification algorithm, the speed ratio between any component is calculated quickly. A configuration preference method was established for the defined evaluation objectives via hierarchical analysis. Finally, a prototype was built based on the screening results. The test results showed that the optimal solution could accurately meet the design requirements and realize two-speed transmission. The accuracy of the configuration and screening method of the magnetic gear two-speed transmission system proposed in this article is verified. It provides a theoretical reference for the design of high-performance magnetic gear two-speed transmission.