The effects of ball interactions on the dynamic behavior of a ball balancer rotating at speeds above the translational resonant frequency of the system.

Many applications are inherently rotational in nature. These applications range from industrial products to consumer products. As seen in a traditional frequency response plot, the motion of a rotating imbalance does not approach zero as the forcing frequency is increased. Unlike a traditional forced mass spring oscillator, the motion of the rotating imbalance approaches some non-zero value. To account for this residual motion, some systems utilize a balancing device to reduce this motion. These balancing devices can be passive or active, depending on the design considerations. This paper will focus on the traditional, passive ball-type balancer due to its simplicity and extensive use in application. This paper derives the equations of motion for a vertically oriented ball-type balancing system. Due to the high non-linearity of these equations, a fourth order Runge-Kutta numerical integration method is used. The ball balancer equations of motion contain the proper physics needed for full operation such that the ball balancer can translate horizontally, vertically and rotate angularly in the presence of gravity. Acceleration terms are included such that a wide range of operating conditions can be tested. Additionally, n number of balls are present, which are affected by rolling friction and viscous fluid drag. Unlike many numerical models published in the past, the ball-to-ball interactions are not neglected within this model. These interactions include collisions, and train formations and separations. An application of the method presented by (Henon 1982) is utilized where the equations of motion are altered such that an exact integration step can be solved. This is based on the need for a displacement step (collision) or a force step (separation). Although the model presented can accommodate n number of balls, only a maximum ball count of two is considered. It is shown how the behavior of the balls affect the motion response of the ball balancer at rotational velocities above the translational resonance of the system. It is seen that a critical transition is reached; the operating point at which the ball balancer becomes effective at offsetting an eccentric mass. It is also seen that ball balancer displacement decreases until a point of saturation, after which ball balancer displacement increases. Also for the two ball case, it is shown that the spatial characteristics of the balls do affect steady state motion. The angle that separates two contacting balls alters the center of gravity of the train of balls such that the balancing capacity of the system is reduced. Although this effect is shown to be small for a two ball case, the balancing capacity is further reduced as the angle between two contacting balls becomes larger

SIRM 2017

This volume contains selected papers presented at the 12th International Conference on vibrations in rotating machines, SIRM, which took place February 15-17, 2017 at the campus of the Graz University of Technology. By all meaningful measures, SIRM was a great success, attracting about 120 participants (ranging from senior colleagues to graduate students) from 14 countries. Latest trends in theoretical research, development, design and machine maintenance have been discussed between machine manufacturers, machine operators and scientific representatives in the field of rotor dynamics. SIRM 2017 included thematic sessions on the following topics: Rotordynamics, Stability, Friction, Monitoring, Electrical Machines, Torsional Vibrations, Blade Vibrations, Balancing, Parametric Excitation, and Bearings. The papers struck an admirable balance between theory, analysis, computation and experiment, thus contributing a richly diverse set of perspectives and methods to the audience of the conference

Synergistic approaches to ultra-precision high performance cutting

Diamond milling allows for the flexible production of optical and high precision parts, but suffers from poor setup and production speeds. This paper presents recent advances that aim towards achieving high performance (HPC) and high speed cutting (HSC) in ultra-precision machining. After a short introduction, the benefits of high speed cutting for both metals and brittle-hard materials are shown. Thereafter, novel mechatronic devices are presented that enable an automated balancing of the applied air bearing spindles and the application of multiple diamond tools on one tool holder and by thus, contribute to HPC. These developments are supplemented by a novel linear guiding system based on electromagnatic levitation that, along with a dedicated model-based control system, enables fast and precise movements of the machine tool. After presenting the recent developments in detail, their synergistic performance is assessed and an outlook to future developments is given. © 2020 The Author

12th International Conference on Vibrations in Rotating Machinery

Since 1976, the Vibrations in Rotating Machinery conferences have successfully brought industry and academia together to advance state-of-the-art research in dynamics of rotating machinery. 12th International Conference on Vibrations in Rotating Machinery contains contributions presented at the 12th edition of the conference, from industrial and academic experts from different countries. The book discusses the challenges in rotor-dynamics, rub, whirl, instability and more. The topics addressed include: - Active, smart vibration control - Rotor balancing, dynamics, and smart rotors - Bearings and seals - Noise vibration and harshness - Active and passive damping - Applications: wind turbines, steam turbines, gas turbines, compressors - Joints and couplings - Challenging performance boundaries of rotating machines - High power density machines - Electrical machines for aerospace - Management of extreme events - Active machines - Electric supercharging - Blades and bladed assemblies (forced response, flutter, mistuning) - Fault detection and condition monitoring - Rub, whirl and instability - Torsional vibration Providing the latest research and useful guidance, 12th International Conference on Vibrations in Rotating Machinery aims at those from industry or academia that are involved in transport, power, process, medical engineering, manufacturing or construction

12th International Conference on Vibrations in Rotating Machinery

Since 1976, the Vibrations in Rotating Machinery conferences have successfully brought industry and academia together to advance state-of-the-art research in dynamics of rotating machinery. 12th International Conference on Vibrations in Rotating Machinery contains contributions presented at the 12th edition of the conference, from industrial and academic experts from different countries. The book discusses the challenges in rotor-dynamics, rub, whirl, instability and more. The topics addressed include: - Active, smart vibration control - Rotor balancing, dynamics, and smart rotors - Bearings and seals - Noise vibration and harshness - Active and passive damping - Applications: wind turbines, steam turbines, gas turbines, compressors - Joints and couplings - Challenging performance boundaries of rotating machines - High power density machines - Electrical machines for aerospace - Management of extreme events - Active machines - Electric supercharging - Blades and bladed assemblies (forced response, flutter, mistuning) - Fault detection and condition monitoring - Rub, whirl and instability - Torsional vibration Providing the latest research and useful guidance, 12th International Conference on Vibrations in Rotating Machinery aims at those from industry or academia that are involved in transport, power, process, medical engineering, manufacturing or construction

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018