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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Rotary compact power pack for series hybrid electric vehicle

Amirian, Hossein, Pezouvanis, Antonios, Mason, Byron A., Ebrahimi, Kambiz M. January 2013 (has links)
No / This paper presents a new-designed compact power pack for a series hybrid vehicle. A new type of rotary induction machine with an outer rotor construction is designed to be coupled with the novel rotary internal combustion engine (ICE) with cylindrical crankcase in order to form the compact power unit. The starting and generation performance of the designed machine as well as the overall vehicle performance is analysed. Results show that the proposed power pack has the best performance in terms of fuel economy, emissions and battery charging compared to the existing power units in ADVISOR. Over a city cycle, fuel economy is increased by up to 47% with emissions reduced by up to 36% and over the highway cycle, fuel economy is increased by up to 69% with emissions reduced by up to 42%.
2

Energy Efficient, Electric-Hydraulic Power Pack / Energieffektivt el-hydrauliskt powerpack

Nyman, Johan, Rankka, Amy January 2015 (has links)
Along with increased oil prices and rising environmental issues, a demand for alternatives to combustion engine driven hydraulic applications has risen. In the field of mobile hydraulics, the hydraulic applications have traditionally been driven by the combustion engine of the vehicle on which they are mounted. By instead using a battery driven power pack the hydraulic application is able to operate without the engine running, saving fuel costs and reducing sound levels. In this thesis, the concept of using an electric-hydraulic power pack with a variable-speed electric motor and a fixed-displacement hydraulic pump to provide power to a truck-mounted loader crane is investigated. This concept is compared to an electric-hydraulic system imitating the conventional combustion engine system by using a fixed-speed electric motor connected to a variable-displacement pump. The use of a variable speed motor where the speed can be controlled electrically by a control unit creates possibilities of using different control strategies to improve the efficiency and responsiveness of the application. The efficiencies of the two electric-hydraulic systems are compared by constructing a physical test rig and performing measurements in a test lab. The tests have shown an increased efficiency of about 20 \% when using the variable speed configuration. Three different control strategies are also investigated and tested on a simulated model. The simulations show that very good responsiveness and robustness can be achieved by using a hydraulic flow feed forward controller with a complementary pressure feedback controller. Furthermore, by controlling the hydraulic flow to the heaviest of the crane loads entirely with the flow from the hydraulic pump, the hydraulic pressure can be reduced and energy efficiency increased.
3

A UNIQUE CAPABILITY: THE 82D AIRBORNE DIVISION AND ITS MEMORY OF THE DOMINICAN INTERVENTION

Guerrero, Anthony Joshua January 2023 (has links)
In 1965, the United States invaded the Dominican Republic to prevent the creation of a “second Cuba.” The invasion and subsequent occupation of the Caribbean nation maintained peace in Santo Domingo beneath the banner of a multi-national peacekeeping force representing the Organization of American States (O.A.S.) as a provisional Dominican government prepared for a democratic presidential election. Although operation Power Pack, the U.S. military name for the intervention, is one of the largest uses of armed force in U.S. – Latin American history and both military and foreign policy leaders deemed the operation a success, few members of the U.S. military seem to remember Power Pack today.The one exception to this is the U.S. Army’s 82d Airborne Division. Unlike other U.S. military branches, or other parts of the U.S. Army, which fail to remember the intervention, the 82d Airborne remembers the intervention and has gone to great lengths to celebrate and memorialize its role in Power Pack. The division’s production of a commemorative book, the construction of political and intellectual discourse buoyed by the operation’s success, and the construction and maintenance of memorials and monuments to Power Pack make it clear that the organization has made a deliberate effort to maintain a collective memory of the conflict. A fuller understanding of why the 82d has maintained these memories is key to understanding why other U.S. military organizations chose to disregard their memory of Power Pack and allows scholars to begin to assess the cost of the military’s forgetfulness. / History
4

Hydraulické posunovače / Hydraulic pullers

Votava, Michal January 2016 (has links)
This diploma thesis deals with the design of the hydraulic puller. Furthermore, the diploma thesis presents the analysis of possible design solutions. It includes processing the selected design of the hydraulic puller with parameters: maximum pushing force 50 kN, speed of work movement 0,05 m.s-1. The analysis by using finite element method (FEM) is made. The next part of thesis includes the design of hydraulic circuit of puller. In the last part of thesis there is the design for replacement of hydraulic puller by mechanical systems.
5

Hydraulické posunovače / Hydraulic pullers

Kvasnica, Tomáš January 2009 (has links)
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.
6

Hydraulické posunovače / Hydraulic pullers

Pavelka, Roman January 2011 (has links)
This diploma thesis deals with the mechanical proposal of hydraulic puller. Furthermore, it includes the detail design solutions. The project also includes the calculation of the hydraulic puller parameters: maximum pushing force is 60 kN, speed of movement is 0.1 m s-1. This work also contains of stress analysis FEM with I-DEAS software. Following part deals with the design of hydraulic circuit for driving puller. At the end of work there are options for replacements of hydraulic puller by mechanical systems.
7

Design and experimental investigation of an additive manufactured compact drive

Matthiesen, Gunnar, Merget, Daniel, Pietrzyk, Tobias, Ziegler, Stephan, Schleifenbaum, Johannes Henrich, Schmitz, Katharina 25 June 2020 (has links)
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.

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