Advantages of V-shaped magnetic rotor structures in electric motors

In permanent magnet synchronous motors (PMSMs), the rotor structure has a decisive impact on the motor’s efficiency, power density, and operational stability. Due to their outstanding overall performance, V-shaped permanent magnet rotors are widely used in new energy vehicles, power tools, home appliance motors, and industrial servo systems.

The V-shaped permanent magnet rotor is a type of embedded permanent magnet rotor. Its magnets are primarily high-performance neodymium-iron-boron (NdFeB) H/SH/UH/EH grades, embedded in a “V” shape within the rotor core. Magnetic bridge structures are incorporated between the magnets and on the outer side to provide mechanical strength and regulate the magnetic circuit. This configuration creates a specific angle between the magnets and the rotor core, enabling the simultaneous output of both magnetic resistance torque and permanent magnet torque.

Image of a V-shaped magnetic steel rotor

The core advantages of the V-shaped magnet rotor lie primarily in its comprehensive performance and engineering adaptability. Building upon the permanent magnet torque, this structure fully utilizes the magnetic resistance difference in the rotor to generate magnetic resistance torque, thereby achieving a superposition of magnetic field torque and magnetic resistance torque. Under the same volume conditions, this design yields higher torque density and stronger output capability. Additionally, due to the V-shaped arrangement of the embedded magnets, the difference in inductance between the d-axis and q-axis is significantly increased. This provides the motor with excellent weak-field speed regulation capabilities in the high-speed range, effectively expanding the high-efficiency operating range. It is particularly suitable for applications in new energy vehicles and high-speed motors. In terms of mechanical reliability, the embedded magnets eliminate the risk of magnet ejection during high-speed operation and do not require complex external restraint structures, resulting in higher overall long-term stability.

In terms of applications, thanks to its performance and reliability advantages, the V-shaped magnet rotor has been widely adopted in new energy vehicle drive motors, industrial servo motors, robotic joint motors, and high-speed, high-power-density PMSM systems.

The above provides an overview of the V-shaped magnet rotor.