|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1992 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1991 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1990 : ¥1,200,000 (Direct Cost : ¥1,200,000)
As industrial robotic manipulators become intelligent, dexterous devices are demanded which have multi degrees of freedom and the capability of proceeding a complicated task flexibly. Developing these devices, we have encountered the problem, how to make a multi functional device in limited space. Although the designer has paid attention to minimize the weight of an endeffector, a multifunctional endeffector often causes the increase of the total weight. Therefore, development of a small and light actuator with high torque density has been desired, that is, a single joint with multidegree of freedom.
A spherical induction motor was built and tested by Laithwait. The structure of a spherical motor with parallel mechanism was proposed by Vachtsevanos However, The mechanical design of a spherical induction motor is complicated because of lamination technology to avoid eddy current and rolling supports for a spherical rotor.
In order to eliminate these problems, we have developed a new spherical motor by ultrasonic motor's technology which has significant potentials in many applications. An ultrasonic motor is an unconventional motor based on utterly new principle of generating torque by ultrasonic vibration. Comparing with conventional electric motor driven by mutual action of current and magnetic field, it has many prominent characteristics.
1) Low speed and high torque 2) No braking mechanism, 3) Small and light structure
4) High torque density
In our researcher, we have succeeded in developing a spherical ultrasonic motor, especially, the development of a stator. Based on experiments to determine optimal design parameters of a stator (applied voltage, thickness of lining material and contact force between a stator and a rotor), we have designed an optimal spherical ultrasonic motor and succeeded in driving the new motor effectively. We can expect that this motor will be used in space environment.