Indiana University-Purdue University Indianapolis (IUPUI) / This dissertation focuses mainly on the airgap-less electric machine. An extensive literature review has been presented along with a systematic study that included analytical modeling, simulation with both steady-state and transient analysis, prototype building, and experimental validation. In this type of device, the rotor is allowed to touch the stator at a contact point, which maximizes the internal flux and therefore the electromagnetic torque. A higher torque density motor is proposed in this dissertation due to a reduced reluctance caused by zero airgap situation. A comparison with other high torque density electric machines demonstrates the advantages of the proposed machine. Switched reluctance motor for hybrid vehicle, integrated magnetic gear, induction machines, are some examples of the machines with lower torque density than the airgap-less electric machine. This machine will maximize the generated torque allowing these type of machines to be competitive in applications where hydraulic motors are prevalent, i.e., low-speed and high-torque requirements. Hydraulic motor systems face two major problems with their braking system and with low efficiency due to a large number of energy conversion stages (i.e., motor-pump, hydraulic connections and the hydraulic motor itself). The proposed electric motor, unlike hydraulic motors, converts electrical energy directly to mechanical energy with no extra braking system necessary and with higher efficiency. The evolution of the airgap-less electric machine from three poles to 9 bi-poles is discussed in this dissertation. The modeling of this machine with a minimum number of poles is discussed before a generalization is presented. The simulation and analysis of the airgap-less electric motor has been done using Euler integration method as well as Runge Kutta 4th order integration method due to its higher precision. A proof-of-concept electric machine with nine magnetic bipoles is built to validate the theoretical assumptions.

The main purpose of this diploma thesis is to design turbocharger rotor using rolling element bearings. The diploma thesis is compiled from two specialized search parts dealing with turbocharger rotor and rolling element bearing computation, respectively. The application of the particular rotor using the multi body system Adams – View is described in the following chapter. In the last chapter, one can find the comparison between rotor using bearing with steal and hybrid ceramic rolling element. Also, there is compariosn between rolling element bearing and journal bearing. In the maximum rotor speed, the decrease of more than 50 % in power loss, due to usage of rolling element bearing, resulted from this comparison.

This diploma thesis deals with design of rotor of synchronous reluctance machines. There is a theoretical description of rotor geometry of synchronous reluctance machine that respects natural flow of magnetic flux inside complete rotor. The parametric model of rotor is made with usage of ANSYS Maxwell and Matlab software. Furthermore, the parameters of the machines are confirmed using the same program. Finally, changes of motor parameters are observed in connection with different rotor geometries.

The current development in the field of electric machinery is focusing on high-speed electric machines. This opens also other fields related to high-speed machines. One of them are magnetic bearing systems. Tradition approach of using ball bearing brings a few problems in design dealing with friction at high speeds. Together with magnetic bearings, development is their control. Faster chips opened a new way of thinking of control and helped to evolve robust control loops. The biggest advantage of magnetic bearing is non-friction run and almost no maintenance. Compare to traditional ball bearing, a magnetic bearing system needs more space and in some applications could happen that the shaft will be twice as long. This problem can be solved designing complex system with motor and integrated magnetic bearing what leads to downsizing. In this master thesis, the design of magnetic bearing for 12kw, 45000rpm is discussed. It focuses on practical design and correlations between parameter selection. The analytical approach is used to sketch the design and optimization is done afterwards. Problem with an analytical design is that it doesn't cover all parasitic phenomenae and thus numerical modelling snd optimization are demanded. Also, the critical speed analyze is included in this thesis. The results of the work will be used for manufacturing prototype as an extension to the existing high-speed machine.

This paper is focused on customization of induction machine type STM71-4L. The need of optimal mechanical design is presented, to achieve sufficient synchronizing reluctant torque, which will result in rotor synchronization with stator magnetic field. Final mechanical design is suggested after research, which considers influence of the essential rotor dimensions on resulting electromechanical torque. This is provided with usage of finite element method calculation. As a result of the thesis the combination of two basic machines – induction machine and synchronous motor is presented. The measurement on induction motor, and it´s modified versions is presented in following chapters. In the last chapter the results of optimization and measurement are discussed and compared.

This master's thesis considers by single-phase asynchronous motor. The first part discuss about construction, principle of operation and basic parameters of this motor type. It also discussed the emergence of torque and torque characteristics of the different types of engines. The second part explains the basic ways of obtaining grip moment including outline the principles of functions particulars constructions types, which is produce in practice. In the third part is minutely analyse single-phase asynchronous motor with auxiliary phase and permanently conect capacitor, including method of assign size of a capacitor. Fourth part section provides the principles of the procedure for calculating basic parameters of the single asynchronous motor with auxiliary phase. At the last part is accomplished a calculation of single-phase asynchronous motor with permanently conect capacitor at auxiliary phase including comparation with already manufacturing motor.

This master´s thesis treats of all asynchronous motor. The project is about type and distribution motors, about differences between three-phase and single-phase machines and efficiency. In one of the chapters describes a particular type of engine with all the parametersfrom the manufacturer. This engine is completely analyzed and it is measured in detail. Then the project deals with the division, the calculation of losses and subsequent possibilities to increase the efficiency of induction motor. In the last chapter is calculation of single-phase motors, based on the engine produced.

Balancing of rotors is used to remove unwanted vibrations caused by uneven distribution of mass around the axis of rotation of the rotor. Operation of an unbalanced rotor may causes shortening of bearing life, fatigue of materials and deformation of shafts. This work deals with construction of a balancing machine (balancer). Because of its good properties, a soft bearing type balancer was chosen for construction. This type of balancer achieves higher sensitivity at the cost of calibration required for each type of rotor. To capture the magnitude of vibration electrodynamics sensors were chosen. To enter data and display results a microprocessor is used.

Diploma thesis deals with calculation and design study of air-cooled Wankel engine and simple mechanical stress of its main parts.

This thesis deals with dynamic behavior of swirl turbine vibrating in a liquid. Primarily is studied decrease of natural frequencies of rotor due the interaction with fluid environment, namely for different levels of submerged rotor in fluid. After that follows the detection of natural frequencies of swirl turbine in operating speed. The problem is solved by computational modeling in ANSYS system. For this solution is used acoustic elements method. The results are compared with experiment.