New manufacturing technologies allow the development of micro-motors with dimensions of a few millimetres. These motors usually work at high rotational speed and offer only small torque to drive their specific load. For typical applications, for example in medical equipment it is desirable to use drives with low rotational speed at high torque. Therefore gearboxes are used in many cases. Gearwheels for micro-mechanical systems have to be manufactured in very small dimensions. Mechanical tolerances of the manufacturing technology as well as of the assembling techniques become a very important factor for the performance of the micro-mechanical systems. If the internal friction of the system becomes too high, the output torque is reduced significantly. In this case the system performance can not be guaranteed. Therefore the characterization of such motors and gearboxes is necessary either during the state of development as well as for quality control in production. For such a test equipment it is desirable to have the possibility of measuring torque at different working conditions. A recently developed torque sensor suitable for rotating micro-systems will be presented. It is based on a very sensitive spring element to which the torque to be measured has to be applied. For minimizing the influence of the measurement procedure on the measuring object the very small deformation of the spring element is detected contact-less by a laser triangulation system with a simple electrical voltage output. First industrial applications of the sensor will be described.
展开▼
