Development of a Mixing Machine Driven by a Spherical Motor

This study develops a mixing machine driven by a spherical motor that can rotate around any axis. The developed mixing machine is composed of a rotor, a stator, a control PC, an electro-magnet excitation circuit, and a power supply. The rotor that its outer diameter is 200 [mm] is composed of double spherical shells in order to contain liquid in its inner spherical shell. Totally 91 permanent magnets are arranged in almost spherical symmetry on the inner surface of the outer spherical shell. On the other hand, 80 electro-magnets are arranged on the stator of a semi-spherical shell. The applicability of the mixing machine to material production under the condition of small influence of gravitational force is evaluated by mixing experiments to dissolve salt of 50 [g] in water of 200 [g]. The mixing performance is compared for five mixing methods. The results show that the mixing performance of the method to change randomly the rotation direction is only slightly lower than that of the method of rotating continuously around a horizontal axis that exhibits the highest mixing performance.