Guntis Strautmanis

The Influence of a Torus Shaped Auto-Equalizer on the Vibrations of Rotary Systems

Rotary systems are frequently used in different kinds of machines and devices, and therefore the problem of vibrations observed in rotary systems play a crucial role. The article analyses a ball-shaped auto-equalizer with a vertical axis the body of which is placed relatively eccentric to the rotation axis. The auto-equalizer with a torus-shaped body contains one ball-shaped adjustment mass moving freely within the body of the auto-equalizer both in circularly and crosswise directions. This reduces resistance force in the ball motion mode to the minimum, and, at the same time, decreases the possibility of starting the auto-equalizer.Making the analysis of experimental research on the ball-shaped auto-equalizer has led to the conclusion that, along with the working mode when the ball stops relatively at the rotating body from the opposite to imbalance side, there is another mode when the ball is moving relatively continuously to the body of the auto-equalizer. It has been stated that the ball in the working mode is affected by forces trying to move it to the body of the auto-equalizer opposite to the imbalance. The closer is the ball to the optimum place the smaller is tangential force influencing the ball. A mathematical model for the auto-equalizer consisting of two differential equations has been developed.

The Detection of Battery Screwdriver’s Optimal Working Modes when Assembling Fixed Threaded Joint Considering Allowable Tightening Torque in Case of Equal Screw Length

In presented paper, the screwdriver’s electric power consumption studies depending on the corresponding fixed threaded joint’s assembly time are carried out. So far there are no recommendations from the tool manufactures for screwdriver’s optimal operating modes (the conclusion is made on the base of the attached instructions which provide instrument manufacturers), when evaluating this aspect upon taking into account the electrical power consumption and assembly time for different types of fixed threaded joints (wood, metal, plastic, etc.) and also taking into account obtainable tightening moments. In the examined literature sources which deal with the opportunities concerning the optimization of the automated assembly processes of fixed threaded joints, not enough attention is paid to the reduction of the instrument’s energy consumption which is one of the main tasks in the industrial process because it directly impacts production costs.

The analysis of ball's motion in the torus-shaped autoequalizer

The reduction of vibrations in rotary systems is necessary condition for the development of constructions with high quality requirements. Among the devices that are able to reduce rotors vibrations are automatic balancers with balls, liquid, etc. Autoequalizers with torus-shaped body contain one ball-shaped adjustment mass that can freely roll both in the ring direction and in the cross section. This enables reducing to the minimum the force of resistance at the balls moving, but simultaneously decreases the chance of launching the autoequalizer in the autobalancing regime. It has been stated that the ball in the working state is influenced by forces that are aimed at moving it in the body of the autoequalizer towards the side opposite to the imbalance. The design of an autoequalizer that ensures working state in which at rotation the ball stops relative to the autoequalizers body opposite to the imbalance has been experimentally worked out. The autoequalizer is made up of the mathematical model with t...