Controllable vibration of mobility links of production mechanism

Introduction. The work subject is investigating friction characteristics of the moving surfaces of the production mechanism (PM) links including executive mechanisms (EM), and work tools (WT) of technological machines (TM) in the low-speed zone of an asynchronous motor (AM) powered from an autonomous voltage inverter (AVI) in the “AVI - AM” system. The work objective is to find a technical solution to the reduction of the friction effect in the PM links on the frequency-controlled drive (FCD) mechanical characteristics in the low- and creep-speed zone, and also, to the validation of the rated vibration feasibility of the mobile links in the PM guides under the starting-braking AM modes. Materials and Methods. To solve the research problems, the concept of bimodal AVI control that provides the formation of quasi-sinusoidal voltage for AM power supply in the “AVI - AM” system with the harmonic coefficients Kuu > 8% is used. The program control of the amplitudes of the fundamental 5th and 7th harmonics of the stator current is applied. These harmonics form the fluctuating torques on the AM shaft and cause the normalized vibration of the PM links. Research Results. The justification and experimental proof of the AVI control feasibility providing a project change in the AM shaft vibration amplitude and a decrease in the effective friction coefficient of the PM moving links aiming at the elimination of the seizure of the links under the PM operation conditions are obtained. Such an effect is possible under the AM rotor spinning in the low current frequency (0.5-20 Hz) zone which is typical for the slow-speed motion of PM under the starting-braking FCD modes. Discussion and Conclusions. The application domain of the developed technical solution covers many PMs with FCD for which the short-time operation modes (with CY of 40% and more) are considered basic. Thus, the use of the effect of vibration linearization of the friction coefficient in the PM links allows the following: to reduce the AM breakaway voltage and significantly extend the FCD speed control range, to increase the ride quality and improve the PM out put link kinematics on which the WT is fixed.