Rotor assembly, cage type motor and preparation method of motor

The invention relates to the technical field of motor manufacturing, in particular to a rotor assembly, a cage type motor and a preparation method of the motor, the rotor assembly comprises a rotor core, a connecting ring and a conducting bar, the rotor core is provided with rotor grooves in a penetrating mode, and the rotor grooves are distributed in the radial direction of the rotor core; the rotor slots comprise starting slots, running slots and connecting bridges for communicating the starting slots with the running slots, and the distance between the starting slots and the excircle of the rotor core is smaller than that between the running slots and the excircle of the rotor core; the connecting rings are arranged at two axial ends of the rotor iron core; the rotor grooves of the rotor iron core are filled with the conducting bars, the two ends of each conducting bar are connected with the two connecting rings respectively, and the rotor assembly can meet one-time die-casting forming on the basis that th