Abstract
A novel anti-symmetric type ultrasonic motor is proposed in this study. By applying anti-symmetric constraints on a unimorph piezo thin-disk vibrator, an in-plane vibration mode with multi-driving areas, same rotating direction, and approximate deformed displacement can be acquired. Furthermore, by appropriate cutting edges, the deformation of the other edges will be enhanced further, for example, the driving speed of the vibrator with “70°-110°_12 -13.5_cut” constrains is increased 26 % compared with the same vibrator but without any cutting edges. A rotor thus can be rotated efficiently by the vibrator’s multi-driving edges.The proposed anti-symmetric vibrator with “65°-115°_12-13.5_cut” constrains which was made of OBO-31mm piezo buzzer element possesses good driving ability. Its operating range 12~30 Vpp is wider than the range 12~18 Vpp of “3-4-5 type” vibrator in privies study [10]. Its power dissipation and the driving speed are 1.6 W and 1400 mm/s correspondingly when the input voltage is 30 Vpp and the preload is 30 gw; its vibrating speed on each driving edges can still reach to 250 mm/s when the preload applied up to 200 gw. The proposed vibrator not only expands the operating voltage range but also reduces the power consumption about 62 % and promotes motor’s efficiency about 50 % according the experimental comparative results with the “3-4-5 type” one.Summery, the proposed anti-symmetric type ultrasonic motor has merits of multi-driving ability, higher diving torque, and steady structure that can expand its applications to thin-disk fans and cooling pumps which need larger torque or turn many rotors at the same time in Biotech.