Design and analysis of the secondary structure for the slot-less tubular permanent magnet linear synchronous motor

This paper focuses on the secondary structure of the slot-less tubular permanent magnet linear synchronous motor (TPMLSM). The leakage flux and the magnetic field distribution of the secondary of the motor with the rectangle pole were analyzed firstly. To decrease the big leakage on the axis and improve the usage rate of the iron, the similar V-shaped and U-shaped poles were provided. Finite-element method was obtained to analyze the leakage flux on the non-magnetic axis and in the air-gap. Based on this, the magnetic concentrating characteristic of the new pole was summarized. Besides, the strengthening characteristic was also revealed by analyzing the flux density in the mechanical air-gap and in the slot-less winding for the U-shaped pole. Finally, the key parameters of the similar U-shaped pole were optimized and researched.