Modeling a bidirectional free-wheel coupling device for uses in high reductions and high torque

Abstract

In this work a prototype of a coupling device to be applied in high velocity reductions, high torque and possibility of rotating inversion is presented. Commonly, under the first two requirements, worm gears are employed in the primary transmission. However, the implementation of these last transmissions is complex when the system has to rotate in both directions, which can be dangerous to the transmission system due to the inversion-blocking of the worm gears. In order to overcome this circumstance, authors propose a mechanical device by friction disks for coupling in both directions, employing the concept of free-wheel. In the presene case the principal contribution, counter like other free-wheel concepts, is that the coupling process can be done in both rotation directions. This offers more versatility to the presence of changes in the rotation sense, and also reduces the mechanical difficulties of a single worm-wheel transmission that has to rotate in both senses. A simple mathematical model for the analysis of the transmission is described. Sensors are connected to capture angular position, angular velocity and angular acceleration. Finally different studies are presented in order to characterize the parameter of the analytic model. This device can be employed in wheels of vehicles adapted for people with walking inabilities, as well as in equipments that have motion inversion, in milling and sifting machines among others.