This thesis is focused on the security and improving of electrical rotating machines service life, especially asynchronous motors. Work includes a description of the most common disorders, short description of the asynchronous motor cage casting, analysis of provided decommissioned motors with photo documentation. The last part of this thesis is focused to vibrodiagnostic of asynchronous motor with simulated imbalance and motor emplacement by laser.

This thesis is concerned with vibration analysis of the roots blower chassis. In the beginning it describes methods of solution in low frequency region. Next part is about finite element model of the chassis and computing natural frequencies, eigen modes and vibration spreading and analysis possible construction changes which should lead to lower vibrations.

This work deals with the matter of powertrain vibration reduction, focusing on the transmission. These units, depending on the purpose of utilization, consist of a high number of dimensionally complex components. These need to possess features, selected already in the design phase, which would guarantee smooth and quiet operation. A properly designed tooth profile and the related specified accuracy of manufacturing are one of the most important features. The basic function and the purpose of transmissions application indicate a relatively wide range of operating speeds and transmitted loads. Moreover, combination of both loading with improperly designed string’s parameter can cause a number of various problems. The vibration initiation with related noise from gear mesh belong to the most significant sources of issues. There are multiple mechanisms of oscillation initiation. Even when using the latest trends in the development of teeth, when their shape is upgraded and developed to meet specifically given load range, the above mentioned irregularity of transferred torque cannot be completely eliminated. Therefore, it is necessary, already in the design phase, to eliminate the transmission paths by which are vibrations transmitting to other components. People perceive this action in the form of vibration, noise, or temperature change in the surroundings. With the increasing comfort levels and number of produced vehicles the reduction of vibration and noise of machinery parts becomes stricter, including gears. The experimental approach is primarily used to assess the accuracy of designed gearboxes, but it is a very expensive and a time consuming method. Therefore, it is necessary to develop a process that utilizes both numerical simulation and experimental approach but also combines the advantages of both, particularly time and cost savings and comparability of results. For this purpose, the experimental gearbox is designed and manufactured including the single-stage gear enabling variable configurations in terms of the ratio change. The gearbox is subjected to numerical simulation of different complexity levels, as well as technical experiment. Furthermore, the universal virtual prototype in Multi-Body System ADAMS is created, which reflects the impact of several key parameters for proper functionality, such as axial distance, backlash, gear mesh stiffness, shaft mounting stiffness (bearings) and modal properties of the shafts and gearbox housing. Last but not least, the impact of imbalance or irregularity of input shaft speed is incorporated. The last part focuses on a brief description of the application of the presented methodology – modelling of vibrations on the tractor gearbox.

Title: The Use of Vibration in Sports and Health Care Objectives: The aim of this study is to confirm or refute established hypotheses. Hypotheses: 1. The use of vibration loading improves muscle strength. 2. The use of vibration loading improves bone mineral density. 3. The use of vibration loading can influence balance. Methods: This diploma thesis is elaborated as search form. It is based on exploration of available literary sources, clinical trials accessible through electronic databases of medical and sports, and library catalogs. The resources from sport, physiology, biomechanics, and various medical disciplines (osteology, physiotherapy, kinesiology) were used also. Results: Due to retrieval process of whole body vibration training it was found out that this method can improve muscle strength, bone mineral density, balance and mobility. The effect depends on chosen parameters of whole-body vibrations. Under certain conditions whole-body vibration training could represent an alternative or a supplement to conventional training in order to increase muscle strength and bone mineral density or improve balance and mobility of elderly. The selection of right vibration parameters could support ordinary physical therapy of some neurological disorders. Keywords: vibration, whole-body vibration...

Title: The Use of Vibration in Sports and Health Care Objectives: The aim of this study is to determine whole-body vibration training as potential training method in sport and health area. The usage of vibration training should increase strength, bone mineral density, and balance. Methods: This diploma thesis is solely theoretical. It is based on review of available literary sources, clinical trials accessible through electronic databases of medical and sports, and library catalogs. The resources from sport, physiology, biomechanics, and various medical disciplines (osteology, physiotherapy, kinesiology) were used also. Results: The research concluded that the usage of whole-body vibration of an appropriate frequency or acceleration respectively could represent an alternative or a supplement to conventional training in order to increase muscle strength and bone mineral density or improve balance and mobility of elderly. The selection of right vibration parameters could support ordinary physical therapy of some neurological disorders. Keywords: vibration, whole-body vibration training, muscle strength, balance, bone mineral density, neurological disorders, physical therapy

My diploma work is focusing on the health problems of selected factors in the working enviroment of grinding the metal castings. There are high-risk factors, which are harmful to worker´s health, especially physical stress, noise, dust and vibrations, which are passed on hands. The employer is under the obligation to take precautions to carry on worker´s health, in consideration of exceed the health limits. The aim of this diploma work was setting the efficiency of precautions to health protection in work enviroment. The situation had been monitoring in a company in the South Bohemia over ten years. There were used results of factor´s precautions (noise, dust, vibrations) in work enviroment, where workers grind the metal castings by hand grinders. The monitoring ensemble was created by employess in a company, which makes the metal castings by hand grinders in its work enviroment. To data collecting were used the following methods: non-aligned observation, conversation with the chief of the company, studying of positive law and technical literature incl. test codes of the health institute (department Ceske Budejovice). The data of the test codes were processed by the secundary analysis and summarized to tables and graphs. Within qualitative analysis I determinated four research questions, which were answered gradually in my work: 1)Which precautions are carry out by employers to particular factors of employee´s health protection? 2)What is the factor´ s efficiency? 3)What impact do the precautions have on results of factor´s measuring? 4)Which precautions can I recommend on the grounds of the evalutation of the work enviroment? Both means of collective and individual protection belong to the precautions of worker´s health protection today. The technical, technologiacal and organisational precautions are included to collective protections. The individual precautions are focusing especially on employees and offer the substitute solutions. All precautions are specific to individual factors. I found out, that all precautions, which are used by the employers in work enviroment of metal casting, are effective. Especially we can talk about the precautions to protection of employee´s health against excessive dust (instalation of air ventilation with strong effect), which caused the exceed of dust concetration in work enviroment of grinding. Finally I can say, that this branch of metal casting has been connecting with certain high-risk factors all the time. Although all the protective precautions has been realized, the health limits given for noise, vibrations passed on hands and dust are still exceed. For this reason it´s very important to regularly inform the workers of high-risk factors, which they could meet in their work enviroment of cast grinding.

The thesis describes a realization of the automatic self tuning system for sevenstring guitars. There are comparisons of commercial and uncommercial solutions for six-string guitars. There is also evaluation of useful parts for seven-string guitars. Thesis contains a description of a requirements for individual parts and a control software with respect on real guitar properties and used computing algorithm. In the second part of thesis, there is a description of final system design and its realisation including the control software. This is also related with testing of the entire system.

The goal of this diploma thesis is to clarify possibilities of usage of acoustic emission as a hydraulic machinery diagnostics tool. Especially for exposing presence of ruptures or cracks in the parts of machine, assuming changes in acoustic exposure of the part during operation. This clarification is based on series of simple measured experiments, which consist of monitoring the bolt placed in fluid stream inside of a pipe. This bolt was preloaded against inner wall of pipe by appropriate tightening torque. This preload is supposed to simulate effects of the size of rupture. High preload simulates small rupture or none in object and respectively small preload is supposed to simulate big rupture. A group of pressure sensors and accelerometers measures experiments and their evaluations are processed by script created in software MATLAB. Outputs of this script are charts with effective values of respective sensors from the entire record split into individual frequency spectrums. These charts compare spectrums of each configuration to judge effects of parameters changes.

The thesis deals with the design of the experimental testing rig. Test rig is designed to measure NVH transmission parameters. First, basic knowledge of vibro-acoustic measurement is discussed. This is followed by an evaluation of the most commonly used power devices to derive real loads on measured gearboxes. In more detail, a back-to-back test rig is disassembled among other things. In the thesis are described two main components, which are composed of a connecting element and a test bench. Both components were optimized during the design due to their modal properties. Numerical modal analysis was performed in ANSYS Workbench software. The thesis also includes strength calculations performed using both numerical and analytical approaches. The indispensable result of the design work is the complete drawing documentation. Finally, measurements of vibrations and noise on the physically made connecting element assembly have been performed and subsequently evaluated.

This master’s thesis is deal with the area of determining the static transmission error in spur gears. Nowadays, around vibration and noise formation, the issue of transmission error is being discussed quite often. In the first part of this master’s thesis, there is a description of the theoretical requirements concerning the above stated issue. These theoretical requirements are further applied in parametric planning of the spur gears as well as in measuring the transmission error itself. In this master’s thesis, both the detailed description of planning the parametric model of spur gears and the strain-stress analysis may be found. These requirements are needed for calculating the transmission error. In conclusion of this master’s thesis, specific results of the static transmission error in spur gears achieved at diversifying load torque, center distance modifications as well as tip relief modifications of spur gears are being presented. The issue was solved by computation approach with the help of CAD software called Creo Parametric and FEM software called Ansys Workbench and Ansys Mechanical APDL.