<p>Despite the increasing demand for the hydraulic pump noise reduction, there is yet to be an established straightforward solution to reduce noise emissions. This is primarily due to a lack of understanding of the complete mechanism underlying noise generation and propagation, which involves complex interactions between three domains. Study of the physical phenomena of the hydraulic pump noise is typically separated into three categories, namely fluid-borne noise (FBN), structure-borne noise (SBN), and air-borne noise (ABN). In this light, this study examines the noise generation and propagation of hydraulic pumps in all three domains numerically and experimentally, taking external gear pumps (EGPs) as a reference. </p> <p>In conventional pump noise studies, the outlet pressure ripple in the fluid domain, which typically refers to has been the key focus to minimize, and FBN typically refers to the outlet pressure ripple. Fortunately, attempts to minimize ripples have resulted in some promising solutions that are now on the market (e.g., dual-flank gear pumps). However, since the noise generated by gear pumps involves several other significant and coherent noise sources, this approach has some limitations. In view of this, the current study describes FBN in a wider context to include all potential noise sources in the fluid domain, and their mutual effects on noise are investigated.</p> <p>Another aspect of the vibration and noise of the pump that is not often investigated is its “field” behaviors. Many significant works in vibroacoustic analysis or noise solutions rely on the simple measurements of acceleration or sound pressure at a single or few local points. Since vibration and noise are functions of not only time but also "space", this practice has also served as one of the obstacles to a comprehensive understanding of noise generation. Therefore, this study contributes to topic of the vibroacoustic field behaviors.</p> <p>Furthermore, when prototyping or designing new pumps, inefficient trial-and-error methods are often used, and it demonstrates the necessity of the acoustic model of the pumps for virtual prototyping. The major limiting factor towards the development of this type of models is high computational costs. Another technical challenge is that most of vibroacoustic analysis commercial software usually requires the user’s manual works for the simulation setup. In this regard, another aim of this study is to develop a computationally inexpensive and automated acoustic model that does not need manual inputs of users, so that the model can be used as a virtual prototyping tool with various design parameters.</p> <p>To sum up, the primary goal of this research is to numerically and experimentally investigate the vibroacoustic field behaviors and formulate the acoustic model to be used as a virtual prototyping tool with the experimental validation. To achieve these objectives, this research employs the well-established computational and experimental methods of vibro-acoustic analysis.</p> <p>The analysis of FBN makes use of the HYGESim tool, which has been developed to study EGMs at Maha Fluid Power Research Center. This tool solves the main flow based on the lumped parameter approach in conjunction with different solution schemes for lubricating interfaces and body dynamics. From the HYGESim results, all potential noise sources within the working fluid, such as inlet and outlet pressure ripple and dynamic pressure at the tooth space volumes, hydrodynamic journal bearings, and the lateral lubricating interface, are properly mapped to the structure using appropriate simplifications. </p> <p>When it comes to SBN, the modal superposition approach is exploited for the fast prediction of vibration fields. Therefore, considerable efforts are expended both numerically and experimentally to obtain accurate modal information. Particular attention is paid to the modeling of the mechanical connections between components and modeling of constraints in numerical modal analysis using the finite element method (FEM). Moreover, the vibration mode shapes are categorized according to the dominant motions that the pump body exhibits. Then, two different approaches, namely the full numerical model and the hybrid model, are introduced for the estimation of the vibration field during the operation; for the modal expansion, the former uses numerical modal information, while the latter uses experimentally determined modal information. Finally, the numerical model results are compared to the operational deflection shape (ODS) measured during pump operation, and a good agreement is observed.</p> <p>For the ABN prediction, the boundary element method (BEM) is used by taking the predicted vibration information as an input. The BEM solver development is elaborated to numerically replicate the acoustic environments where the noise measurement is conducted. With the developed BEM solver, two units that have the different gear and groove designs that fit into the same casing are tested, and as the key outcome, their sound power level, sound power spectrum, sound pressure distributions are presented. For model validation, the noise measurements are performed according to the ISO standard in the semi-anechoic chamber at Maha using a custom-designed robot arm. These validations demonstrate the ability of the developed model to predict the overall sound power levels with an averaged error of 1.87 dB and capture the general trends of measured sound power spectrum and sound pressure level distribution under various operating conditions. Furthermore, the developed model provides the reasonably fast computation time.</p> <p>Finally, using the developed acoustic model, a parametric study is performed with the backflow groove as a design variable. It is discussed how the volumetric efficiency and noise performance vary with the design changes, which demonstrates the model potential as a virtual prototyping tool.</p>

This Diploma thesis occupies with design of hydraulic puller. In work are mentioned possible types of construction. Choice construction of puller is disposed with parameters: maximum pushing force 50 kN, speed of piston rod 0,05 m/s. This work also contains FEM analysis by computer programme I-DEAS. The work also occupies with design of fluid drive.

In recent years, additive manufacturing (AM) has become one of the most revolutionary and promising technologies in manufacturing. The process of making a product layer by layer is also often referred to as 3D printing. Once employed purely for prototyping, AM is now increasingly used for small series production, for example in aerospace applications. The paper starts with a motivation for AM in hydraulic applications and the development of an AM internal gear pump. For a better understanding of the manufacturing process, a brief introduction to AM highlighting the advantages and challenges is given. The AM internal gear pump is part of an electrohydraulic power pack, which is used to power an electrohydraulic actuator (EHA). The power pack contains all necessary peripherals to realise the hydraulic system of the EHA. The AM process allows for new design possibilities, but the process differs strongly compared to subtractive manufacturing processes and therefore is outlined here. The paper concludes by presenting measurement results of the AM internal gear pump.

В данной магистерской диссертации представлены результаты разработки методов повышения точности преобразователей вращательного движения в поступательное для систем отсчета перемещения рабочих органов станков с ЧПУ, что и является целью выпускной квалификационной работы. Актуальность темы обусловлена тем, что точность машин и механизмов является основной характеристикой их качества. Традиционные механические передачи (зубчатые, реечные и др.) имеют широкое применение во всех отраслях машиностроения. Требования к точности изготавливаемых деталей существенно ужесточаются, поэтому необходимо непрерывно совершенствовать методы повышения точности передач. Научная новизна обусловлена разработкой новых методов повышения точности систем отсчета перемещений путем уменьшения или ликвидирования кинематических погрешностей и погрешностей от износа преобразователей вращательного движения в поступательное. Рассмотрены элементы, применяемые при построении современных систем отсчета перемещений и возникающие в них погрешности. Проведен анализ существующих методов уменьшения кинематических погрешностей и погрешностей от износа преобразователей вращательного движения в поступательное. На его основе разработаны: метод отсчета перемещений рабочего органа станка с компенсацией погрешностей ходового винта; метод снижения износа передачи винт-гайка скольжения; метод снижения износа передачи винт-гайка качения; метод отсчета перемещений рабочего органа станка с коррекцией кинематических погрешностей рейки; метод снижения износа зубчато-реечной передачи; насос, предназначенный для использования при реализации перечисленных методов. В ходе работы над магистерской диссертацией было подано шесть заявок на изобретения. В результате было получено пять патентов: патент на изобретение №2750575 «Насос шестеренный реверсивный», патент на изобретение №2756797 «Передача винт-гайка качения», патент на изобретение №2764105 «Зубчато-реечный привод подачи металлорежущего станка с ЧПУ», патент на изобретение №2768807 «Устройство отсчета перемещений рабочего органа машины с ходовым винтом» и патент на изобретение №2767381 «Передача винт гайка скольжения». На рассмотрении в ФИПС находится заявка на изобретение №2021114570 «Зубчато-реечный привод подачи рабочего органа тяжелого крупногабаритного металлорежущего станка». / This master's thesis presents the results of the development of methods for precision improvement of reference systems for the movement of movable operating element of CNC machines, which is the purpose of the final qualifying work. The relevance of the topic is due to the fact that the precision of machines and mechanisms is the main characteristic of their quality. Traditional mechanical gears (gear, rack and pinion, etc.) are widely used in all branches of mechanical engineering. The requirements for the precision of manufactured parts are significantly tightened, so it is necessary to continuously improve methods for improving the precision of transmissions. The scientific novelty is due to the development of new methods for improving the precision of displacement reference systems by reducing or eliminating kinematic errors and errors from wear of rotary motion converters to translational. The elements used in the construction of modern displacement reference systems and the errors arising in them are considered. The analysis of existing methods for reducing kinematic errors and errors from wear of rotary motion converters to translational motion is carried out. Based on it, the following methods have been developed: the method of counting the movements of the movement of movable operating element of the machine with compensation of errors of the lead screw; the method of reducing the wear of the transmission screw-nut sliding; the method of reducing the wear of the rolling screw-nut transmission; the method of counting the movements of the movement of movable operating element of the machine with correction of kinematic errors of the rail; the method of reducing the wear of rack and pinion transmission; the pump, designed for use in the implementation of the above-mentioned methods. During the work on the master's thesis, six applications for inventions were submitted. As a result, five patents were obtained: patent for invention No. 2750575 "Reversible gear pump", patent for invention No. 2756797 "Rolling screw-nut transmission", patent for invention No. 2764105 "Rack-and-pinion feeding drive of CNC metal cutting machine", patent for invention No. 2768807 "Device for counting the movements of the operating member of a machine with a drive screw" and patent for invention No. 2767381 "Sliding screw-nut gearing". The application for invention No. 2021114570 "Rack-and-pinion feeding drive of the operating member of a heavy large-sized metal-cutting machine" is under consideration in the federal institute of industrial property.

Диссертация на тему «Разработка новых конструкций реверсивных шестеренных насосов для систем смазки возвратно-вращательных механизмов экскаваторов» содержит 95 страниц текста, рисунков – 49, формул – 22, использованных источников – 18, иллюстрационный альбом, включающий 15 листов формата А1 графической части. Ключевые слова: системы смазки, реверсивные механизмы, реверсивный насос, шестеренный насос, консистентная смазка, циркуляционная смазка, карьерные экскаваторы, привод поворота, привод подъемной лебедки. Предмет исследования: проблемы систем смазки современных карьерных экскаваторов. Цель работы: разработка схемы и конструкции насоса, обеспечивающего бесперебойную подачу смазывающего вещества при постоянном реверсировании его ведущего вала. Итогом работы является разработка двух концептуальных вариантов шестеренного реверсивного насоса для узлов, совершающих возвратно-вращательные движений. Насосы могут работать от основного привода, без использования дополнительного двигателя. Так же в работе представлен пример использования данных насосов в узлах карьерного экскаватора ЭКГ-20, таких как редуктор подъемной лебедки и редуктор привода поворота с расчетом параметров насоса для последнего. В процессе работы над диссертацией была оформлена заявка на патент на полезную модель «Реверсивный шестеренный насос». Заявка зарегистрирована в Роспатенте с приоритетом от 23.04.2019. Регистрационный номер заявки 2019112339. / The dissertation on the theme "Development of new designs of reversible gear pumps for lubrication systems of return-rotational mechanisms of excavators" contains 95 pages of text, figures – 49, formulas – 22, used sources – 18, an illustrative album, including 15 sheets of A1 format of the graphic part. Key words: lubrication system, reversing mechanisms, a reversible pump, gear pump, grease lubrication, circulating lubrication, mining shovels, swing drive, the drive of the lifting winch. Subject of research: problems of lubrication systems of modern mining excavators. The purpose of the work: development of the scheme and design of the pump, ensuring uninterrupted supply of lubricant with constant reversal of its drive shaft. The result of the work is the development of two conceptual variants of the gear reversible pump for units performing reciprocating movements. Pumps can operate from the main drive, without the use of an additional engine. Also the paper presents an example of the use of these pumps at the nodes of a mining shovel EKG-20, such as reducer lift winch, and the gear drive rotation calculation of pump parameters for the latter. In the process of working on the thesis was issued a patent application for a utility model "Reversible gear pump". Application to patent with priority of 23.04.2019. Registration number of the application 2019112339. The practical usefulness of the work lies in the fact that this pump is ready for use in many areas of engineering, as shown by the example of mining equipment.