Abstract
Currently, practical wearable power assisted devices are developed by many companies and universities in Japan. These are also expected to apply to the welfare field. In this study, we had developed a new actuator that consists of more than two small DC motors, and named it as Sliding-Type Multi-Motor Power Unit (S-MMPU). The most significant structural feature of S-MMPU is that the output torque of each motor is transmitted to output shaft by using sliding contact between sphere attached on output shaft of each motor and a flat disk attached on output shaft of S-MMPU. Then S-MMPU has two functional features that are high back-drivability and torque upper limit function. The torque upper limit function is one of important features to guarantee the mechanical safety of the wearable power assisted device for human. To measure the quantitative characteristic of S-MMPU, we had developed prototype equipment of S-MMPU using 8 motors. We had examined the relationship among the output torque, the normal directional force between the spheres and the disk and motor current by using the experimental equipment. We had confirmed that the prototype of S-MMPU has the torque upper limit function from the experimental results.
