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1
Srněnský, Jan. „Návrh systému automatické výměny vřetenových hlav“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318528.
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The purpose of this thesis is to design system for automatic exchange of spindle heads shared by several machines. Spindle heads are transported between these machines and placed to the position for exchange. The system also allows storing of heads. Requirements for system are load capacity of 2 000 kg and placing a spindle head to the exchange position with precision of ± 0,02 mm. The thesis consists of three parts. The first part involves search of head exchange principles and shows possible ways to transport heads and other elements that could be used in the system. In the next part are several possible solutions introduced and the selection of the best one is made. The last part contains the design of the chosen solution, visualisation, description and calculations. The result is design of two solutions which are described in this work.
2
Vazovan, Ľubomír. „Vřeteník a naklápěcí hlava frézovacího multifunkčního obráběcího centra s vodorovnou osou vřetena“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402637.
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The thesis contains of draft, calculations, CAD model and drawing documentation of the moltifunctional machining center with horizontal axis of spindle. This thesis is one of the four parts with which connection ensue the machine-tool. In the first part of my work, there is a constructional draft of the headstock which will enable milling, turning and drilling. In the introduction of this part is headstock research which is solving the most important parts of the headstock of machine . Consequently, technical calculations are acoomplished. Based on these calculations, a specific constructional draft of the headstock is crafted. In the next part of my work, I do research in the area of removable paring milling heads. After this part, there are technical calculations and the specific constructional draft. In the entire work, there is emphasis put on simplicity and functionality.
3
Sovadina, František. „Návrh vřeteníku soustruhu“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443734.
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The thesis deals with the design and construction of headstocks of a turning centre. The aim is to design a spindle with an output of 20 kW and a maximum speed of 5000 1/min. The research part of the thesis is focused on the description of the basic parameters of the headstock and turning centres needed for the construction of the headstock and contains an analysis of the available spindles on the market. The next part of the thesis deals with the selection and calculation of cutting conditions and the necessary parameters. Analytical calculations are then verified using FEM analysis. At the end of the thesis, a 3D model was developed and headstock drawing documentation.
4
Vyplašil, Jan. „Návrh horizontální výměnné hlavy - VA1 –C“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229757.
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Diploma thesis deals with the concept of interchangeable straight spindle head type VA1-C, used for automatic clamping in 80 kW spindle head from production of TOS Kuřim. Thesis contains survey of interchangeable heads, analysis of the spindle housing, strenght analysis of the spindle with the safety calculations in critical sec-tions and analysis of the clamping mechanism together with the calculation of the camping force, which holds the tools in the spindle. Analysis of the camping mechanisms contains calculation of the contact stress between balls and housings. All results are shown in the graphs. In the last part of the thesis are described the construction elements using the model of the interchangeable head. Enclosed is the assembly drawing of the spindle head, bill of material, detail drawing of the spindle and also 3D model of the interchangeable spindle head.
5
Nedbal, David. „Návrh manuální pravoúhlé frézovací hlavy určené pro technologické operace na středně těžkých obrobcích“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382413.
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This thesis deals with mechanical design of right-angle manual milling head for headstock of horizontal boring machine of Fermat production. The thesis includes research of milling head types, Fermat production heads, but also heads of competition companies with similar parameters like designed head. Design part of thesis is about describing used components of chosen solution. The thesis includes also technical report describing calculation of load spectrum from machining, design of gears, calculation of reactions in spindle bearings, spindle deformation and control of spindle bearings. The end of the thesis describes financial evaluation including also comparation with competitive milling heads with similar parameters.
6
Svoboda, Ondřej. „Konstrukce pravoúhle prodloužené frézovací hlavy pro horizontální vyvrtávačku“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231164.
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This thesis deals with design of right-angled elongated milling head for horizontal boring machine of FERMAT production. The thesis includes a detailed research of milling heads, a description of the head´s basic components and certain commercially available head´s comparison. Design part is describe components description and the design. Calculations are focused on determinating of forces generated during machining, setting of loading spectrum and the power load calculating individual gears during machining. In the next part is calculation of the reactions in the spindle bearings included, the equivalent load and durability of spindle bearings, spindle deformation and spindle bearings optimum distance. The thesis also includes spindle strength calculation, horizontal and vertical shafts analysis, gears design with helical teeth and gear strength. The thesis describes the design of extended milling head and particular design nodes which is supplemented by the 3D model. In this thesis is also included a drawing of assembly and components.
7
Tocháček, Jakub. „Návrh zrychlovací hlavy pro vřeteník horizontální vyvrtávačky“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241857.
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This thesis deals with conceptual design of spindle speeder head for headstock of horizontal boring machine of FERMAT Company. The thesis includes research part, which is initially given to horizontal boring machines and their accessories and continues with an overview and comparison of spindle speeders that are currently on the market. The work includes technical report, which is aimed on design of the belt drive including the idler pulley. Design of belt drive is based on the output of the calculation program developed by manufacturer of synchronous belts. Calculation part, mainly focused on the spindle and its bearings, is preceded by a part in which are calculated cutting forces for two technological operations. Calculation of the spindle part contains strength calculation of the spindle and equivalent basic rating life of spindle bearings, including calculating of radial stiffness at the spindle nose and calculation of optimal distance between the spindle bearings. At the end of the technical report is a financial summary, description of used components and the chosen design solution. The drawings which are based on model assembly processed in 3D CAD system, contains a drawing of the entire device and drawings of selected components.
8
Raszka, Pavel. „Vývoj vřeteníku pro horizontální vyvrtávací centrum“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401042.
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The master´s thesis deals with the design of the headstock for the horizontal boring center and design of the milling head. In the first part of the thesis, a search is made in the field of boring machines, main parts of boring machine headstock and milling heads. Based on this theoretical analysis, the input parameters for the calculation of the tension, power and torque characteristics of the headstock are selected. Subsequently, the design of the headstock and milling head is done using a 3D model.
9
Ryšavý, Radek. „Návrh obrábění součásti včetně její montáže“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402502.
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This diploma thesis is focused on piece production of the component and its subsequent assembly. It is an interchangeable spindle head marked VA1 from the product portfolio of TOS KUŘIM - OS, a.s. The aims of the diploma thesis include the characteristics of the assigned component, the subsequent analysis of the current manufacturing and assembly process. In the price calculations chapter, the direct and indirect input costs for the part production are quantified. Proposals to improve production were presented to the company and offered for possible implementation.
10
Matěja, Josef. „Konstrukce multifunkčního obráběcího centra“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230916.
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The Diploma thesis deals with the design solution of multi-functional machining centre, especially with one of its parts – the design of the slide ram and vertical feed incl. the choice of convenient tool heads for the slide ram. The introducing part deals with the numerically controlled machines and centres generally, especially with the portal-type ones. It contains description of individual machine parts including examples of accessories from product plans of domestic and foreign producers. The second part of the Diploma thesis contains calculations and design solution of the slide ram and feed including the choice of the most suitable accessories applicable for this purpose. In the final phase the model of the slide ram has been introduced in the imersion virtual reality and integrated in the complete machine design. The Diploma thesis has been elaborated using the relevant technical literature.
11
Horák, Vítězslav. „Konstrukce frézovací hlavy pro CNC soustruh s nastavitelným sklonem“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417456.
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This thesis deals with design of CNC lathe milling head with B axis. Thesis includes research in CNC turning machines, their tool systems and overview of manufacturers of milling B axis. It also includes calculation of machining forces, design of spindle and design of B axis including necessary calculations. Part of this thesis is also 3D model and assembly drawing, 2 manufacturing drawings and list of items.
12
Leden, Pavel. „Výroba tělesa pro klíčový zámek“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229935.
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The diploma thesis is focused on the production of body for cylinder locks. This is production of very small and accurate parts. In the first part there is described the function of the lock, the sort of cylinder locks, their components and the basic types of safety elements. The second part is focused on the production of given type of body. The thesis deals with either existing production technology or proposals of possible innovation. This firstly consists in new organization of manufacturing operations. At the close we can find comparison of existing technology and new proposal.
13
Wells, Allan R. „Spectral analysis of multi-spindle machining heads /“. Online version of thesis, 1994. http://hdl.handle.net/1850/12019.
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14
Aurand, Alexander M. „Dynamic Moments on the Cervical Spine Imposed by Head-Mounted Equipment“. The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1430747355.
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15
Lopik, David van. „A computational model of the human head and cervical spine for dynamic impact simulation“. Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/7643.
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Injury to the human neck is a frequent consequence of automobile accidents and has been a significant public health problem for many years. The term `whiplash' has been used to describe these injuries in which the sudden differential movement between the head and torso leads to abnormal motions within the neck causing damage to its soft tissue components. Although many different theories have been proposed, no definitive answer on the cause of `whiplash' injury has yet been established and the exact mechanisms of injury remain unclear. Biomechanical research is ongoing in the field of impact analysis with many different experimental and computational methods being used to try and determine the mechanisms of injury. Experimental research and mathematically based computer modelling are continually used to study the behaviour of the head and neck, particularly its response to trauma during automobile impacts. The rationale behind the research described in this thesis is that a computational model of the human head and neck, capable of simulating the dynamic response to automobile impacts, could help explain neck injury mechanisms. The objective of the research has been to develop a model that_,, can accurately predict the resulting head-neck motion in response to acceleration impacts of various directions and severities. This thesis presents the development and validation of a three-dimensional computational model of the human head and cervical spine. The novelty of the work is in the detailed representation of the various components of the neck. The model comprises nine rigid bodies with detailed geometry representing the head, seven vertebrae of the neck and the first thoracic vertebra. The rigid bodies are interconnected by spring and damper constraints representing the soft-tissues of the neck. 19 muscle groups are included in the model with the ability to curve around the cervical vertebrae during neck bending. Muscle mechanics are handled by an external application providing both passive and active muscle behaviour. The major findings of the research are: From the analysis of frontal and lateral impacts it is shown that the inclusion of active muscle behaviour is essential in predicting the head-neck response to impact. With passive properties the response of the head-neck model is analogous to the response of cadaveric specimens where the influence of active musculature is absent. Analysis of the local loads in the soft-tissue components of the model during the frontal impact with active musculature revealed a clear peak in force in the majority of ligaments and in the intervertebral discs very early in the impact before any forward rotation of the head had occurred. For the case of rear-end impact simulations it has been shown for the first time that the inclusion of active musculature has little effect on the rotation of the head and neck but significantly alters the internal loading of the soft-tissue components of the neck.
16
Leisti, E. L. (Eeva-Liisa). „Radiologic findings of the head and spine in neurofibromatosis 1 (NF1) in Northern Finland“. Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514271394.
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Abstract
Imaging of the head and spine with CT and/or MRI was performed on 125 Northern Finnish NF1 patients to evaluate the CNS lesions in patients of different ages and their role in diagnosis and follow-up.
Manifestations of NF1 in the head were more common in children than in adults. 77% of the children and 33% of the adults had T2 hyperintense brain lesions. Optic gliomas were present in 29% of the patients, in 44% of the children and 10 % of the adults. 8% of the patients had other intracranial tumours . Spinal lesions were seen in 75% of the patients.
Hyperintense T2 lesions were most common in the age group of 5 to 9 years. During follow-up of the children, the lesions diminished in 25%, remained unchanged in 36%, showed mixed behaviour in 20% and disappeared in 10%. In 15% they increased in size and number. In one patient a malignant tumour developed at the site of a T2 lesion.
Optic gliomas were located intraorbitally and/or prechiasmally in 94%, chiasmally and/or at the hypothalamus in 58% and in other optic areas in 14% of the patients. 52 % of the intraorbital gliomas were bilateral. The gliomas remained unchanged in 68% of the children and 50% of the adults. Other lesions included plexiform neurofibromas, sphenoid bone dysplasias and hydrops of the optic sheath. Optic glioma was more common in children with T 2 hyperintense brain lesions than without them.
The other brain tumours included six astrocytomas, including an affected mother and her son. In one patient the astrocytoma regressed spontaneously. Hydrocephalus was seen in 5% of the patients.
T2 hyperintense brain lesions were more common and numerous in macrocephaly; all macrocephalic children, but only 59% of the normocephalic children were affected. All children without T2 lesions were normocephalic. The brain measurements did not reveal any specific area to be responsible for macrocephaly.
Spinal postural changes and dural ectasias were more common in adults. The spinal cord was affected in two patients. Spinal neurofibromas were seen in 19% of the children and 55% of the adults. Even young children may have severe manifestations. In one family a rare familial type of spinal neurofibromatosis (FSNF) was observed in four adults with bilateral spinal neurofibromas at all levels of the spine.
Although both CT and MRI were valuable in CNS imaging, MRI proved to be the method of choice in detecting T2 hyperintense brain lesions, in evaluating the intracranial extent of optic gliomas and hydrops of the optic sheath and lesions of the spinal cord and nerves. MR imaging proved necessary for evaluating the extent of NF1 manifestations and helpful in the diagnosis, screening and follow-up of NF1 patients.
17
Saavedra, Sandra Lee 1952. „Contribution of spinal segments to control of posture during typical and atypical development“. Thesis, University of Oregon, 2010. http://hdl.handle.net/1794/10530.
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xviii, 125p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.Trunk control is critical for all functional movement, yet little is known about the development of trunk stability. Previous research considered the trunk to be one rigid segment ignoring the complexity of multiple spinal segments. In healthy adults spinal control is so well orchestrated that this assumption is reasonable; however during development and more specifically in pathological conditions in which spinal control is immature or compromised, this assumption may prevent accurate analysis and/or treatment of the condition. This dissertation investigates the mechanisms used by typical infants in gaining postural control of spinal segments for independent sitting. Infant data were compared to data from children with cerebral palsy (CP). The contribution of spinal segments was assessed by stabilizing the trunk in vertical alignment with four levels of support (axillae, mid-ribs, waist or hips). Documentation of postural sway of the head reflected the motor control available in the free segments of the spine. Kinematic data were collected bimonthly from 3 to 9 months of age in typically developing infants and 3-4 times over a 4 month time span in children with CP. The infants' response to external support changed in a non-linear, stage-like fashion as they transitioned from immature to mature spinal control. Head stability emerged first at higher levels of trunk support and gradually progressed in a cephalocaudal pattern to lower levels of support. Emergence of functional sitting was associated with mastery of postural control in the lower lumbar and pelvic regions of the spine. The severity of CP was related to the level of spinal control achieved. Children with severe CP had control in the cervical or upper thoracic spine while those with moderate CP had control into the mid to lower thoracic spine. In addition, behavioral patterns seen in children with CP were consistent with developmental stages seen in typical infants during acquisition of vertical alignment. These findings challenge the existing clinical practice of evaluating and treating the trunk as a single segment, offer intermediate measures of progression of spinal control and propose that a more specific approach may create the foundation for improved motor outcomes in pathological populations.
Committee in charge: Marjorie Woollacott, Chairperson, Human Physiology; Paul van Donkelaar, Member, Human Physiology; Andrew Karduna, Member, Human Physiology; Shawn Lockery, Outside Member, Biology
18
Perez, Richard. „The Canadian C-Spine Rule and CT-Head Rule Implementation Studies: A Psychological Process Evaluation“. Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19814.
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The Canadian C-Spine (CS) and CT-Head (CT) Rules are tools aimed at improving the accuracy and efficiency of radiography use in emergency departments. This study evaluated whether the Theory of Planned Behaviour (TPB) could explain the inconsistent results from implementation studies of these two rules at 12 Canadian hospitals, where the same intervention resulted in a significant reduction in CS radiography but not CT radiography. It was demonstrated that the TPB model’s proposed relationships between constructs and behaviour could explain the ordering of CS but not CT radiography. However, after examining longitudinal changes of the TPB constructs, it was clear that these changes could not explain the changes in CS radiography ordering. Overall, TPB is unlikely to suggest important ways by which to improve radiography use, for CT because its constructs are not related to radiography ordering, and for CS because of high baseline levels of intention to clinically clear.
19
Bartsch, Adam Jesse. „Biomechanical Engineering Analyses of Head and Spine Impact Injury Risk via Experimentation and Computational Simulation“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1291318455.
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20
Hollingworth, William. „Magnetic resonance imaging of the head, spine and knee : diagnosis, treatment and patients' quality of life“. Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624732.
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21
Pavlova, Elena. „Vestibular control of body orientation in lamprey /“. Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-861-0/.
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22
Muthuswamy, Sivaramakrishnan. „The Arabidopsis nucleoporin NUA is involved in mRNA export and functionally interacts with spindle assembly checkpoint proteins“. The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1262122134.
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23
Pew, Jefferson W. „A Torque Based Power Input Model for Friction Stir Welding“. BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/1100.
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For decades models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for Friction Stir Welding (FSW). To date, there is no definitive relationship to quantify the heat input for FSW. An important step to establish a heat input model is to identify how FSW process parameters affect weld power. This study details the relationship between FSW process parameters and torque for three different aluminum alloys: 7075, 5083 and 2024. A quantitative weld power and heat input model is created from the torque input. The heat input model shows that decreasing the spindle speed or increasing the feed rate significantly decreases the heat input at low feed rates. At high feed rates, feed rate and spindle speed have little effect on the heat input. Process parameter versus heat input trends are verified by measurements of the weld heat affected zones. In addition, this study outlines and validates the use of a variable spindle speed test for determining torque over a broad range of parameters. The variable spindle speed test provided significant improvements over previous methods of determining torque as this new method enabled the torque to be modeled over a broad range of parameters using a minimum number of welds. The methods described in this study can be easily used to develop torque models for different alloys and materials.
24
Lovett, Mathew. „Quantitative Assessment of HSP70, IL-1ß and TNF-a in Spinal Fluid and Spinal Cord Sections of Dogs with Histopathologically Confirmed Degenerative Myelopathy and Control Dogs“. The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366561072.
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25
Williams, Matthew R. „Evaluation of 2D and 3D Command Sources for Individuals with High Tetraplegia“. Cleveland, Ohio : Case Western Reserve University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1238682202.
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Thesis (Ph.D.)--Case Western Reserve University, 2009Abstract Title from OhioLINK abstract screen (viewed on 13 April 2009) Department of Biomedical Engineering Available online via the OhioLINK ETD Center
26
Grip, Helena. „Biomechanical assessment of head and neck movements in neck pain using 3D movement analysis“. Doctoral thesis, Umeå : Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1600.
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27
Kang, Yun Seok. „Evaluation of Biofidelity of Anthropomorphic Test Devices and Investigation of Cervical Spine Injury in Rear Impacts: Head-Neck Kinematics and Kinetics of Post Mortem Human Subjects“. The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313554843.
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28
Berner, Dagmar. „Der Einfluss der Kopf-Hals-Haltung auf die röntgenologische Darstellung der Hals- und Brustwirbelsäule des Pferdes“. Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-114412.
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Pathologische Veränderungen der Wirbelsäule können zur Verkleinerung der Foramina intervertebralia der Halswirbelsäule sowie zur Verkürzung der Abstände zwischen den Dornfortsätzen der Brustwirbelsäule führen. Eine Veränderung der Kopf-Hals-Haltung kann ebenfalls die Dimension der Foramina intervertebralia sowie die Abstände zwischen den Dornfortsätzen beeinflussen. Die Bestimmung des Einflusses der Kopf-Hals-Haltung auf die genannten Parameter bei der radiologischen Darstellung der Wirbelsäule war deshalb das Ziel der vorliegenden Arbeit. In drei unterschiedlichen Kopf-Hals-Haltungen wurde die Halswirbelsäule von 25 klinisch unauffälligen Pferden im laterolateralen Strahlengang dargestellt. Laterolaterale Röntgenaufnahmen der Brustwirbelsäule von 23 Pferden ohne klinische Anzeichen einer Erkrankung der Wirbelsäule wurden ebenfalls in drei verschiedenen Kopf-Hals-Haltungen angefertigt. Die Auswertung dieser Aufnahmen erfolgte mit Hilfe von neu entwickelten Messmethoden, die eine hohe Reproduzierbarkeit aufwiesen. Auf den Aufnahmen der Halswirbelsäule wurde die Länge der Wirbelkörper und die Dimension der Foramina intervertebralia bestimmt. Zusätzlich wurden die Winkel zwischen angrenzenden Halswirbeln ermittelt. Der Abstand zwischen benachbarten Dornfortsätzen sowie die Breite der Dornfortsätze wurden für die Auswertung der Aufnahmen der Brustwirbelsäule gemessen. Für eine exaktere Auswertung der Aufnahmen der Brustwirbelsäule wurde ein spezieller Bildfilter entwickelt, der durch eine bessere Detailerkennbarkeit zu einer genaueren Messung der Streckung führte. Sowohl für die Breite der Dornfortsätze als auch für die Länge der Wirbelkörper der Halswirbel konnten keine signifikanten Unterschiede zwischen den Röntgenaufnahmen in den verschiedenen Kopf-Hals-Haltungen gefunden werden. Beide Strecken dienten zur Überprüfung des Versuchsaufbaus, um andere Ursachen für eine unterschiedliche Größe der Messstrecken auszuschließen. Die Foramina intervertebralia waren bei tiefer Kopf-Hals-Haltung signifikant größer als bei den anderen beiden Kopf-Hals-Haltungen (p < 0,05). Zwischen hoher und physiologischer Kopf-Hals-Haltung stellten sich nur die Foramina intervertebralia zwischen sechstem und siebten Halswirbel unterschiedlich groß dar (p < 0,05). Die Abstände zwischen angrenzenden Brustwirbeln waren vom achten bis zum vierzehnten Dornfortsatz in tiefer Kopf-Hals-Haltung größer als in den beiden anderen Kopf-Hals-Haltungen (p < 0,05). Diese Abstände nahmen insgesamt von kranial nach kaudal ab (p < 0,05) ab. Der zwölfte Dornfortsatz diente dabei zur Identifizierung der anderen, da er sich signifikant von den schmaleren kranialen und den breiteren kaudalen Dornfortsätzen unterschied (p < 0,01). Die Kopf-Hals-Haltung während der radiologischen Untersuchung beeinflusst sowohl die Dimension der Foramina intervertebralia als auch den Abstand zwischen den Dornfortsätzen. Deshalb sollte diese bei der Auswertung radiologischer Aufnahmen immer berücksichtigt werden. Die Foramina intervertebralia stellten sich bei tiefer Kopf-Hals-Haltung am größten dar und können somit in dieser am besten beurteilt werden, jedoch kommt es zu einer Veränderung der Anordnung der Wirbel, so dass diese nur noch eingeschränkt beurteilt werden können. Eine tiefe Kopf-Hals-Haltung führt zur Vergrößerung der Abstände zwischen den Dornfortsätzen und kann somit die Beurteilung von Röntgenaufnahmen der Brustwirbelsäule, gerade im Rahmen einer Kaufuntersuchung, beeinflussen. Die Kopf-Hals-Haltung bei der Anfertigung von Röntgenaufnahmen der Wirbelsäule sollte standardisiert werden, um durch verbesserte Vergleichbarkeit Manipulationen und Fehlinterpretationen einzuschränkenPathological changes of the spine can lead to reduction of the intervertebral foramina dimensions in the cervical spine and to shortening of the distances between the spinous processes in the thoracic spine. However, alteration of the head and neck position influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Determining the influence of the head and neck position on these parameters during radiological examination of the equine spine was the aim of this study. In three different head and neck positions lateral-lateral views of the cervical spine in 25 clinically sound horses were radiographically obtained. Lateral-lateral radiographs of the thoracic spine from 23 horses lacking clinical signs of spine diseases were taken in three different head and neck positions. Evaluation of the radiographs was carried out with newly developed measurement techniques providing high reproducibility. On the radiographs of the cervical spine the length of the vertebral bodies and the dimension of the intervertebral foramina were measured. Additionally, the angles between adjacent cervical vertebrae were determined. The distances between adjacent spinous processes and the width of the spinous processes were measured for evaluating the radiographs of the thoracic spines. For a more accurate evaluation of the thoracic spine radiographs a purpose-built image filter was developed, which provided more accurate measurement of the distances through better detail recognition. No significant differences were found for the width of the spinous processes of the thoracic vertebrae and the length of vertebral bodies of the cervical vertebrae between the radiographs taken in the three different head and neck positions. Both these distances were used to verify the experimental set-up to rule out other causes for differences in the measured distances. The intervertebral foramina were significantly wider in the low head and neck position than in the other two head and neck positions (p < 0.05). Between the high and the free head and neck position only the intervertebral foramina of the sixth and seventh cervical vertebrae showed different dimensions (p< 0.05). The distances between the adjacent thoracic vertebrae from the eighth to the fourteenth spinous processes were wider in the low head and neck position compared to the other two head and neck positions (p < 0.05). Altogether, these distances decreased from cranial to caudal (p < 0.05). The twelfth spinous process served for numerical identification of the other spinous processes due to its significant difference in width to the narrower cranial and broader caudal spinous processes (p < 0.05). The head and neck position during radiographic examination influences the dimensions of the intervertebral foramina as well as the distances between the spinous processes. Therefore, it should always be considered when evaluating radiographs. In the low head and neck position the intervertebral foramina turned out to be the widest and could be best assessed. However, this resulted in changes to the alignment of the vertebrae and therefore a limited assessment. A low head and neck position leads to an increase in the distances between the spinous processes and could influence the evaluation of radiographs especially if these are taken as part of a pre-purchase examination. During the radiographic examination of the spine the head and neck position should be standardised in order to reduce manipulation and misinterpretation through better comparability of such radiographs
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Stammen, Jason Anthony. „Biomechanical Characterization of the Human Upper Thoracic Spine – Pectoral Girdle (UTS-PG) System: Anthropometry, Dynamic Properties, and Kinematic Response Criteria for Adult and Child ATDs“. The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1344880193.
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30
McBride, Stanford Wayne. „A Numerical Model of the Friction Stir Plunge“. BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1772.
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A Lagrangian finite-element model of the plunge phase of the friction stir welding process was developed to better understand the plunge. The effects of both modeling and experimental parameters were explored. Experimental friction stir plunges were made in AA 7075-T6 at a plunge rate of 0.724 mm/s with spindle speeds ranging from 400 to 800 rpm. Comparable plunges were modeled in Forge2005. Various simulation parameters were explored to assess the effect on temperature prediction. These included the heat transfer coefficient between the tool and workpiece (from 0 to 2000 W/m-K), mesh size (node counts from 1,200 to 8,000), and material model (five different constitutive relationships). Simulated and measured workpiece temperatures were compared to evaluate model quality. As spindle speed increases, there is a statistically significant increase in measured temperature. However, over the range of spindle speeds studied, this difference is only about 10% of the measured temperature increase. Both the model and the simulation show a similar influence of spindle speed on temperature. The tool-workpiece heat transfer coefficient has a minor influence (<25% temperature change) on simulated peak temperature. Mesh size has a moderate influence (<40% temperature change) on simulated peak temperature, but a mesh size of 3000 nodes is sufficient. The material model has a high influence (>60% temperature change) on simulated peak temperature. Overall, the simulated temperature rise error was reduced from 300% to 50%. It is believed that this can be best improved in the future by developing improved material models.
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Al, Sofyani Sharaf. „Analytical Modeling and Experimental Analysis of Metalworking Fluids in theMilling Process“. University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1494853268000644.
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32
Pascart, Tristan. „Étude des modifications osseuses de composition et de structure au cours de l’ostéonécrose de tête fémorale et corrélations étiopathogéniques IRM“. Thesis, Lille 2, 2017. http://www.theses.fr/2017LIL2S049/document.
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La physiopathologie et l'évolution structurale de l'ostéonécrose de tête fémorale (ONTF) sont des processus encore largement méconnus. Les objectifs de cette thèse ont été de rechercher des modifications de composition et de structure de l'os trabéculaire et de l'os sous-chondral dans l'ONTF. Un travail préliminaire s'est intéressé aux modifications de composition osseuse en spectrométrie Raman induites par l'embaumement afin de déterminer les témoins les plus appropriés pour comparer les os pathologiques. Des tissus osseux fémoraux issus de 5 sujets anatomiques embaumés ont ainsi été comparés à ceux de 5 sujets anatomiques frais. Le premier travail sur l'ONTF a consisté à rechercher des modifications des paramètres physico-chimiques minéraux et organiques en spectrométrie Raman de l'os trabéculaire de tête fémorale chez 11 patients ayant une ONTF versus 11 sujets frais. Le second travail concernant l'ONTF a porté sur l'étude de l'os sous-chondral. Cette recherche a prévu l'inclusion de 15 patients ayant une ONTF à 15 patients ayant une coxarthrose nécessitant un remplacement prothétique. Une évaluation IRM avec séquences usuelles, séquences de perfusion et séquences DIXON était réalisée préalablement à la chirurgie. Après la chirurgie, l'ensemble de la tête fémorale était ensuite analysé en nano-scanner (nano-CT), puis des biopsies en zones d'intérêt ont été réalisées et analysées par histologie, nano-CT avec amplificateur de contraste et spectrométrie Raman.RésultatsLa composition des tissus osseux fémoraux des sujets anatomiques frais et embaumés différaient de manière significative sur les paramètres minéraux et organiques. La composition de l'os trabéculaire sur les zones d’intérêt ne différait pas entre les patients ayant une ONTF et le groupe de sujets anatomiques frais après ajustement sur l'âge. Le volume de nécrose définie en IRM par la zone en hyposignal T1 est corrélé au volume de nécrose incluant la zone sclérotique en nano-CT. Concernant l'os sous-chondral, les résultats préliminaires mettent en évidence des différences de composition minérale et organique en spectrométrie Raman au niveau de la plaque souschondrale entre les zones d’intérêt du groupe ONTF et avec le groupe coxarthrose. Les résultats préliminaires qualitatifs des biopsies en nano-CT et en histologie suggèrent que l'atteinte de la plaque sous-chondrale est prédominante sur celle de l'os trabéculaire souschondral. L’évaluation IRM (séquence DIXON) et en nano-CT de la richesse adipeuse suggère une relative pauvreté adipeuse de la tête fémorale mais une richesse excessive du col fémoral.Ce travail apporte des éléments supplémentaires suggérant que la désorganisation de l'os trabéculaire au cours de l'ONTF est une conséquence d'une atteinte massive de l'os sous-chondralIntroductionThe pathophysiology and structural evolution of the osteonecrosis of the femoral head (ONFH) are poorly understood. The objectives of this thesis were to search for modifications of composition and structure of both the trabecular and the subchondral bone occurring during ONFH.MethodsA preliminary study looked into the potential modifications of bone composition induced by embalmment procedures using Raman spectroscopy in order to determine which controls are the most appropriate for comparisons with pathological bones. Femoral bones from 5 embalmed anatomical subjects were compared to femoral bones from 5 subjects that did not undergo any preservation procedure. The first work on ONFH addressed the potential modifications of trabecular bone mineral and organic physico-chemical parameters using Raman spectroscopy. The study included bone samples from femoral heads of 11 patients affected with ONFH and compared them to samples from 11 fresh anatomical subjects. The second study on ONFH addressed modifications of the subchondral bone. The study included 15 patients suffering from ONFH and 15 patients affected with hip osteoarthritis (OA) requiring joint prosthetic replacement. MRI examination that included standard medical sequences as well as experimental perfusion and DIXON sequences was performed prior to surgery. Once removed, the femoral heads were scanned using a nano-CT and samples of regions of interest were performed and analysed using histology, nano-CT with contrastenhancer marking and Raman spectroscopy.ResultsBone femoral mineral and organic composition was significantly altered in embalmed samples. Trabecular bone composition did not differ in any of the regions of interest inside the group of patients with ONFH nor in comparison with the control group of embalmed subjects after adjustment on age. The volume of the necrotic zone defined by the hypo-T1 MRI signal correlates to the volume including the sclerotic zone measured by nano-CT. Regarding the subchondral bone, preliminary results found differences of mineral and organic composition of the subchondral plate between zones of the ONFH group and with the OA group. Qualitative preliminary results from the study of biopsies analysed with the nano-CT and histology suggest that there are alterations of the subchondral plate and of the subchondral trabecular bone to a lesser extent. MRI examination with the DIXON sequence and nano-CT scans suggest that there is a decrease of the adipose content in the femoral head but an increase in the femoral neck in the ONFH group compared to the OA group.ConclusionThis work adds further evidence advocating that trabecular disorganization during ONFH is a consequence of massive alterations of the subchondral bone
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Treffel, Loïc. „Dysfonctions vertébrales et posturales après simulations de la microgravité“. Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ111/document.
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Ce travail de thèse a pour but l’étude des douleurs de dos qui surviennent chez l’astronaute présentant davantage de hernies discales par rapport à une population contrôle. Nos recherches visent à comprendre la physiopathologie de ce phénomène et à étudier les conséquences cliniques de ce déconditionnement vertébral qui participe également aux troubles posturaux. Cet axe de recherche est recommandé par les différentes agences spatiales internationales. Pour cela nous avons eu l’opportunité d’analyser les données dans deux modèles d’études des effets de la microgravité : l’immersion sèche (n=11) et l’alitement tête déclive (n=9) et un état analogue, le confinement (n=4). Seuls les principaux résultats de l’immersion sèche, méthode d’étude nouvelle de notre paradigme, sont rapportés dans ce résumé. Celle-ci a permis grâce à l’imagerie et la spectroscopie par résonnance magnétique nucléaire de la colonne vertébrale, d’analyser en 3 dimensions le disque intervertébral et d’objectiver l’augmentation du contenu en eau (+17%) du volume de ce disque (+9,5%). Les variations du tonus des muscles paravertébraux et des membres inférieurs ont été mesurées avec la très récente et non-invasive technologie MyotonPRO. Une diminution du tonus musculaire (-7,3%) a été retrouvée, associée à une atrophie musculaire (-10,6%) ainsi qu’une perte de force démontrée sur les membres inférieurs. Ces résultats, attestant un déconditionnement musculaire, sont cohérents avec le déconditionnement postural immédiatement après immersion sèche. Nous avons également étudié les paramètres d’occlusion dentaire, qui font partie des entrées posturales et peuvent affecter la bonne stabilité du corps. Finalement deux éléments interviennent dans l’explication des dysfonctions vertébrales : l’augmentation de la taille de la colonne liée à celle du volume des disques intervertébraux. On note également une atrophie des muscles paravertébraux, qui joue un rôle majeur dans la posture. Nous avons par ailleurs montré le rôle de l’occlusion dentaire dans le déconditionnement vertébral et postural. En conclusion : le tonus musculaire, la bonne mobilité vertébrale et l’équilibre de l’occlusion dentaire sont des éléments à préserver pendant et après un séjour en impesanteur, afin d’éviter les effets délétères du déconditionnementThis work focuses on the study of back pain experienced by astronauts, who present with a greater incidence of herniated discs compared to a control population. Our research aims at understanding the physiopathology of this phenomenon and to study the clinical consequences of vertebral deconditioning which also contributes to postural disorders. This line of research has been recommended by the various international space agencies. For this reason, we had the opportunity to analyze data in two models simulating the effects of microgravity: dry immersion (n = 11) and head-down bed rest (n = 9), and a similar state, confinement (n = 4). Only the main results of dry immersion, a new method of studying our paradigm, are reported in this summary. Using magnetic resonance imaging and spectroscopy of the vertebral column, it was possible to analyze the intervertebral disc in 3 dimensions and to objectify the increase in water content (+ 17%) and the increase in intervertebral disc volume (+ 9.5%). Variations in paravertebral and lower limb muscle tone were measured with the very recent, and non-invasive, MyotonPRO technology. A decrease in muscle tone (-7.3%) was found to be associated with muscular atrophy (-10.6%) as well as a loss of strength in the lower limbs. These results, attesting to muscle deconditioning, are consistent with postural impairment immediately after dry immersion. We also studied variations in dental occlusion, which is involved with the maintenance of posture and could affect balance. In summary, two elements are involved in the explanation of vertebral dysfunction: the increase in spine height, related to increased intervertebral discs volume and paravertebral muscles atrophy, which plays a major role in posture. However, we also showed a role of dental occlusion in vertebral and postural deconditioning. In conclusion: muscle tone, good vertebral mobility, and dental occlusion are elements to be preserve during and after an exposure to weightlessness to avoid the deleterious effects of deconditioning
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Min-WeiTsai und 蔡明煒. „Thermal balance optimal design with neural network for a CNC lathe spindle head“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/65hqnx.
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碩士國立成功大學
機械工程學系
106
This study use a water-cooled film module with multiple physical coupling analysis and a neural network model that can estimate the nonlinear thermal distortion at the cutting point of the spindle head to estimate and control temperature distribution of a CNC lathe spindle head. In order to more effectively regulate the thermal errors of the machine tool, this study intends to obtain the simulation data of the key temperature points and thermal deformation of cutting points of the machine structure through numerical simulation analysis verified by the experiment of the real machine tool. Then, the data are input into the neural network for learning and training to establish a model that can quickly and effectively predict the temperature rise - heat deformation of the machine tool structure. In addition, this study uses the particle swarm optimization algorithm combined with the neural network to find the most appropriate water cooling film configuration. Key words：Machine tool, Thermal deformation, Artificial neural network, Particle swarm optimization algorithm, Adaptive thermal balance technique
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Hsu, Chang-Yu, und 許長裕. „A Study on Tolerance Analysis and Adjustment for The Spindle Head of A CNC Lathe“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/43007511207058128290.
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碩士國立中興大學
機械工程學系所
105
Spindle is the key component of a machine tool thus requires high precision. In addition to the precision of the spindle, firm and accurate assembly also play important roles in its final precision. This study is aimed toinvestigating tolerance analysis and adjustment in the assembly of the spindle head system for a CNC lathe. A cost-tolerance model dedicated for this spindle is constructed. Sensitivity and contribution analysis of each tolerancing specification and corresponding fabrication cost, in addition to tolerance analysis, are employed for adjusting tolerancing of the spindle in order to ensure it satisfies precision requirement with lower fabrication cost. For estimating fabrication cost, cost-tolerancing models for different fabrication processes are developed based on cost estimation data from engineering practice. Machining cost can be estimated using the developed cost model through calculating machining time and cost coefficientcorresponding to the machining process. Machining time is calculated from material removal as well as process parameters while fabrication cost is estimated according to processequipment, tool accessories, fixture, labor as well as administration and other costs. Based on this model, a computer spread sheet is also developed for the designer to estimate the fabrication cost in tolerancing design. The main contribution of this study is to build cost-tolerancing model using machining time and the cost coefficient for estimating fabrication cost. This model, together with sensitivity analysis and contribution analysis, provide an approach for tolerancing design of a spindle that satisfies precision requirement with lower fabrication cost.
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Hung, Ming-Chieh, und 洪名杰. „A Study of the Thermal Deformation and Multi-physics Optimization of a Machine Tool Spindle Head“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/24288896063580521495.
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碩士國立中興大學
機械工程學系所
103
In this study the thermal deformation of a 3-axis machining center was analyzed experimentally and numerically. In the experiments, temperature variations of multiple (~40) points on the spindle head structure and the displacement of the cutting point with respect to time were measured. In the numerical analysis, a finite element method software (ANSYS) was utilized to simulate the transient thermal-fluidic-thermal elastic behavior of the spindle head structure. The numerical results are in reasonable agreement with the experimental results. Characteristics of the thermal behavior of the spindle head were discussed based on comparing the experimental and numerical results. It was found that the displacement of the cutting point was significantly titling. The key component that greatly affects this nonlinear thermal deformation (tilting) was revealed to be the ribs on the spindle head. This nonlinear thermal deformation cannot be reduced by using conventional thermal error compensation techniques. Therefore, to address this issue, a novel adaptive thermal balance (ATB) technology was proposed and tested in this study. Small rubber heaters and thermoelectric cooling (TEC) units were used to adjust the temperature distributions on the spindle head. Design parameters of the heaters and TECs were determined from optimization analyses based on the constructed simulation model aforementioned. Experimental results confirmed that by applying the ATB technique, a 77% reduction on the nonlinear thermal deformation can be achieved. In conclusion, the current study provides a comprehensive analysis of the thermal characteristics of the modeled machine tool. Furthermore, the developed thermal balance technology is proven to be able to adaptively and smartly adjust the temperature distribution, which in turn significantly improves the machining accuracy.
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Chiang, Chun-Ting, und 江郡婷. „A Study of Applying Taguchi Method to Improve Grinding Roundness Process for the Bore of Spindle Head“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/tu8e49.
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碩士國立勤益科技大學
工業工程與管理系
105
The primary concern of this study was to develop an effective procedure for optimization of grinding parameters during the process of grinder components. An actual case of internal grinding process for spindle head of grinder was adopted to collect data. The result revealed that the circularity of inner hole was crucial to spindle head quality. The design of experiment to ascertain optimal grinding parameter was conducted by means of Taguchi methods. Following verification was further executed through application of RSM. Based on DMAIC approach of six sigma theory, the result of experiment concluded:(a) A significant increase in Cpk was observed through the verification of approximated optimal grinding parameter and (b) the combination of Taguchi methods and RSM to ascertain optical parameters was prove to be effective due to the conformity between hypothetical value obtained from genetic algorithms and real experiment result. The study findings may serve as a guide for further research on reliability enhancement of grinding machines or related products. Further ensure continuous quality improvement of enterprises.
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Lin, Chih-Hua, und 林志華. „Effect of the Spindle Head Configuration on the Dynamic Characteristics and Machining Stability of a Milling Machine“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/40499155428350809536.
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碩士國立勤益科技大學
機械工程系
103
This study was aimed to investigate dynamic characteristics and machining stability of a vertical milling machine with spindle tooling unit constructed into as different feeding configurations along Z direction. To assess the effect of the different spindle feeding head configuration on the machining stability, we created the finite element models of the two milling machines. To be a realistic model, a spindle tooling model with the modeling of the bearings and tool holder was created and integrated with the vertical machine frame model. The results of the finite element simulations reveal that the feeding configuration associated with spindled head can affect the dynamic behavior of the spindle tooling system to different extent. The spindle with long housing shows superiority in the machining stability over the spindle with short housing. The dynamic compliance and the machining stability induced at the structure mode are greatly affected by the design of spindle feeding configuration, which was found to have a great difference by 48%. While the difference corresponding to these characteristics associated with spindle mode is about 28%. Overall, current results clearly illustrate that effect of the spindle housing design of the feeding mechanism on machining stability can be quantified through the whole machine model integrated with the spindle tool unit and machine frame.
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Chen, Mei-Hui, und 陳美惠. „An experimental and numerical study of thermal balance optimal design for a CNC horizontal turning center spindle head“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/42173098885887473602.
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碩士國立中興大學
機械工程學系所
105
The design of the advanced turning center machine tools is becoming more and more complicated due to the increasing demand on function, cutting speed and cutting quality. The requirement for high rigidity, light weight and thermal stability of the machine tool is increasing, while for a both fast tapping and heavy duty cutting a stable and long term high processing accuracy are needed to be achieved. In the past, most machine tool designers elaborated static and modal analyses in the machine structural design, and relied on the empirical guideline for the cooling system design and compensation techniques for mitigating thermal errors of the machine tools. In recent years, however, emerging numbers of advanced machine tool manufacturers have been applying multi-physics analysis to assist the design and development of the machine utilized for and thermal stability optimizations such as the Thermo-Friendly design concept. Therefore, the development of the analysis and optimal design ability that combines the structural rigidity, dynamic characteristics and thermal deformation stability is essential to the competitiveness of modern machine tool designers. In this thesis, experimental and numerical studies of the heat transfer and thermal deformations for a real computer numerical control (CNC) horizontal turning center were conducted. In the simulation section, a multi-physics model based on the fluid dynamics, heat transfer and thermo-elasticity of the spindle head region including the structure and air flow inside the enclosure was established using a finite element method software (ANSYS Fluent). Experimental measurements of the spindle head temperature and the cutting point deformation are used to verify and correct the simulation model of the basic case. The results of the analyses thus provide the insights for the thermal characteristics of the machine. The simulation model in conjunction with an optimization analysis was thus used for improving the thermal error, for the machine with the information of critical locations and parameters for temperature monitoring and control that corresponds to the Thermal Balance concept. Based on the analyzed results, the design of the cooling fan circulation of the spindle head region was proposed and experimentally tested. It is shown that the appropriate design for the location of the fan can effectively improve the thermal deformation of the spindle head and therefore improve the precision of machining.
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Lin, Sheng-Jie, und 林聖傑. „The Variation of Structural Stiffness of Tool Machine due to the Modification of the Structure of Machine Column and Spindle Head“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44207988938013361174.
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碩士國立彰化師範大學
機電工程學系
97
The objective of this study is to apply finite element analysis to analyze the dynamics of the column and spindle head of Machine tool. The Pro/E is employed to construct the structure the Machine tool, including 3D assembly model. The problem is solved by the use of finite element method. The Pro/Mechanica is applied to obtain crucial designing parameters of dynamics. The variation of natural frequencies, mode shapes, stress distribution and structural rigidity of column and spindle head due to the change of their structures are studied. The result indicates that, as predicted, the location of the axis of center of gravity plays a crucial role; the displacement and torque diminishes with the decrease of the distance between the gravity axis and the symmetrical axis of the machine tool.
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Liu, Chia-An, und 劉家安. „A thermal-fluid-structural multi-physics transient analysis, optimization and experimental study of a 3-axis vertical machining center spindle head“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/71835030708363272702.
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碩士國立中興大學
機械工程學系所
104
This study investigated the thermal displacement characteristics of a domestic three-axis vertical machining center. First, the machining center was operated at different rotational speeds to explore the temperature variation and the thermal deformation of the structure. Based on the experimental measurements, a multi-physics simulation model was constructed, modified and validated. This model was then used to predict the thermal deformation, as well as to evaluate the critical positions of temperature monitoring and control. Moreover, a cooling fan was used to enhance the convective heat transfer of the spindle head. This study further proposed an adaptive thermal balance technology to manage the temperature distribution of the spindle head structure, mitigating its thermal displacement, and thus improving the machining accuracy. Previous studies to the same three-axis vertical machining center that were carried out in our group clearly pointed out that the temperature distribution of the ribs on the spindle head have significant influence to the thermal displacement, especially thermal bending. The optimal locations on the ribs for heaters to adjust the temperature distribution were determined by using optimization software. Experiments were conducted to verify the effects of the heaters at a variety of spindle speed. In addition, a correlation analysis to the temperature and thermal displacement of the cutting point was carried out. With the proposed adaptive thermal balance technology it has been shown that the thermal error of the machine tool can be effectively reduced without changing the structural design of the machine.
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HOUNG, MAO-CHIN, und 洪茂欽. „Predicting Spindle Displacement Caused by Heat using Intelligent Algorithms“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/x6b8tx.
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碩士國立勤益科技大學
電機工程系
107
Many factors, including room temperature, can cause the spindle, motor, screws and other components to heat up as machine tools are used during the machining process. This increase in temperature can cause thermal deformation in the different parts. In this study we used a Mike Machine Industry spherical machine tool, a domestically produced SYNTEC21-TA controller and a POSA belt-driven spindle to test the temperature increase and axial displacement changes at 1000, 1500,2000, 2500, 3000 rpm. Temperature sensors embedded in the front and rear bearings are used to measure nearby temperature and the axial thermal displacement. A KEYENCE laser displacement meter and an NI capture card are used to extract data, which is collected and organized into an Excel format. The regression neural network is used for prediction and compared with the actual value, and the coefficient of determination is 0.95. In addition, this study used a COMSOL simulation analysis software and utilized try-and-error learning to adjust boundary conditions. Simulation of the effects of spindle bearing operations heating on the thermal behavior and axial displacement of the spindle structure was conducted and analyzed. The result is compared with the actual measurement, the temperature rise value error is 1 ° C, and the displacement value error is within 1 .
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Lin, Chia-Chun, und 林家駿. „Conjugate Heat Transfer and Thermal deformation Analysis of High Speed Spindle“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/53285549285621026713.
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碩士國立中正大學
機械工程學系暨研究所
102
The study develops a research method applied for the thermal inhibition on high speed spindle to achieve the goal of diminishing the thermal deformation and improving the precision during the manufacturing process. Firstly, we establish the heat transfer model of high speed spindle, such as the heat source formula and fluid theory model. Next, we apply finite element method to conduct a conjugate heat transfer analysis based on Spalart-Allmaras turbulence model. The content of analysis includes the two types of water channel, axial and helical water channel. Moreover, the numerical result of temperature of helical water channel was compared with the experimental data. Subsequently, we use the previous temperature result as the initial condition so that distribution of thermal deformation could be calculated. The result of numerical simulation near the outlet of water channel and solid indicates a good agreement with the experimental data, including the temperature at steady state. The method is reliable and could predict the temperature distribution of high speed spindle in the future. Key Words: High speed spindle, Thermal inhibition, Finite element method, Conjugate heat transfer, Thermal deformation.
44
WU, MIN-TA, und 吳旻達. „Internal Heat Source Prediction and Thermal Compensation for Spindle in Vertical Machining Center“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/638f4j.
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碩士逢甲大學
機械與電腦輔助工程學系
107
The machine tool is the important development industry in Taiwan, and machining accuracy will request more and more high, the market tendency also advances to intelligent, high-speed and composite development. If the efficiency of tool machining is to be increased, the state of spindle is an important factor affecting machining. When the spindle is rotating at high speed, the bearing will produce heat due to friction, but heat often cause the bearing to be damaged by overheating; In addition, the thermal expansion of the spindle caused by structural changes resulting in thermal error, manufacturers distressed by these problems. The study will explore the bearing heat source, maximum temperature and thermal compensation for vertical machine tool of spindle. At First, the thermal model of spindle is established by finite element analysis software, the relational function is established by curve fitting method, and then the heat source and temperature of the spindle are predicted by different experimental measurement temperature data. The experimental results show that the prediction value of the bearing heat source and maximum temperature can be obtained by measuring the front bearing surface and the cooling oil in real time. In addition, the curve fitting used to find the compensation relational equation between the temperature and the displacement of the spindle at various speeds. Finally, the compensation relationship established by reducing the seven temperature points to four temperature points. The experimental results show that the thermal displacement compensation of the spindle can reduce from 20μm to 5μm by using this relational equation. In the future, I hope that this method will used as the development of spindle overheating early warning function and real-time compensation technology can make a substantial contribution to the machine industry.
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CHANG, MING-LUN, und 張明倫. „The Inverse Method for Estimating the Heat Source of Spindle in Machine Tools“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/qyy5mj.
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碩士逢甲大學
機械與電腦輔助工程學系
107
More than 70% proportion of machining error results from heat. Temperature distribution in spindle change dramatically in contrast with other components in machine tools. In addition, spindles play a crucial role in machining quality. Thermal behavior of spindles thus becomes the ongoing issue researched by academic and industrial. Heat source, bearing, is usually used as the condition which makes Finite Element Method solved or the quality standard for products. However, a mass of parameters for bearing makes heat source approximated difficultly. And also, it is unable to measure heat source by sensors immediately. Therefore, an inverse method is adopted to estimate heat source in different rotating speed and time period in this paper. In numerical verification, it is proved that heat source could be solved with 99.6% accuracy in 3 iteration. Furthermore, it could tolerate with 0.3℃ of normal distribution standard error by two measurement. Measurement intensity is also an important consideration of inverse method. In actual experiment, not only the magnitude of two heat source in different rotating speed and time period is calculated by two measurement as well, but the variation of dynamic preload could be observed by the result of inverse method.
46
Chien, Chia-Hung, und 簡嘉宏. „The Heat Transfer Analysis for Built-In Motor High Speed Spindles“. Thesis, 2002. http://ndltd.ncl.edu.tw/handle/3ky8p2.
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碩士國立成功大學
機械工程學系碩博士班
90
The purpose of this paper is to numerically analyze the three-dimensional heat conduction in a built-in motorized high-speed spindle with helical water cooling. The effects of different heat sources (q = 60 w, 120 w and 240 w), cooling water flow rate (0.4 L/min, 0.8 L/min and 1.2 L/min) and free convection. heat transfer coefficient in atmosphere (h = 5 W/m2-oC, 10 W/m2-oC and 20 W/m2-oC) on the temperature distribution are examined in detail. The numerical results indicate that without cooling liquid, the highest temperature of the spindle could be increased up to about 212 oC. The cooling liquid removes most of the heat produced by the motor. Even though the free convection heat transfer coefficient is increased up to 4 times, the temperature difference of the spindle is just within 1 oC only.
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Lin, Ying-Lin, und 林映伶. „The heat transfer analysis for a high-speed spindle with helical water-cooling chamber“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44191425250971501146.
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碩士國立高雄應用科技大學
機械與精密工程研究所
97
The purpose of this paper is to numerically analyze the cooling and thermal diffusion in a high-speed spindle with helical water cooling chamber. This research uses computational fluid dynamics (CFD) method to simulate the steady-state heat transfer. Simulation software Gambit is used in establishing the model of high-speed spindle with helical water cooling chamber and the grid setting. The achievement of numerical simulation analysis is used in computational fluid dynamics (CFD) software package Fluent. With appropriate boundary conditions, the cooling water has temperature at 293 K, and Kerosene has temperature at 288.6 K. The coolant is at velocity of 0.297 m/s, 0.475 m/s and 0.95 m/s. The spindle is made of SUS405 with thermal conductivity k = 16.3W/m-K. The spindle starts running at temperature of 290 K. The system considered is solved using CFD (Computational Fluid Dynamics) method. The SIMPLE scheme (Semi - Implicit Method for Pressure Linked Equation) is adopted for computation in the numerical procedure in a personal computer. The main impacts on spindle thermal diffusion discussed are heat flux, heat generation rate, forced convection heat transfer coefficient, and the related material parameters. Under the assumption of laminar flow for coolant, the thermal response of the spindle is investigated when it is fixed at three kinds of heat source (60W, 120 W, 250W) and the various flow rate of coolant.
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Lai, Yang-Chi, und 賴揚家. „Transient heat transfer of a built-in high speed motor spindle with water cooling chamber“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/06774192524693700729.
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碩士國立高雄應用科技大學
機械與精密工程研究所
97
This study analyzes the transient heat transfer of a three-dimensional built-in high speed motor spindle using the software of computational fluid dynamics (CFD). A fixed input of heat (q=120W) is provided through the inner spindle wall. the main axis of the heat conduction of analysis. The built-in motor is cooled by a water chamber for continuous running. The cooling water has velocity and temperature at (0.475 m/s; 17℃). The oil is has velocity and temperature at (0.475 m/s; 15.6℃).The spindle is made of SUS405 with thermal conductivity K = 16.3W/mk. The spindle starts running at temperature of 20℃. The system considered is solved using CFD (Computational Fluid Dynamics) method. The SIMPLE scheme (Semi - Implicit Method for Pressure Linked Equation) is adopted for computation in the numerical procedure in a personal notebook computer. The thermal phenomena of the spindle under the effect of Reynolds number and some other parameters are discussed and presented with the heat flux, Nusselt number, and volumetric heat generation rate.
49
鄭吉宏. „Thermal analysis of built-in-motor spindles and design of heat sink“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/51140302853383824381.
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碩士逢甲大學
機械與電腦輔助工程學系
104
This paper discusses a high-speed motor spindle having cold vapor flow channel of fin design and use of the property of symmetry axis spindle simplify eventually reduced to a spindle 30 degrees sector, the use of 3D models to create conjugate heat transfer models and analysis spindle heat transfer.We analyse with and without fins, channel width, difference pressure and different fin materials. Through the study, we find that the best way to remove heat is the natural convection, thermal radiation, cooling channels and convection effect of rotation. In addition, the spindle temperature will be lower when the channel width, air mass flow rate and fins thermal conductivity become bigger. Finally, we find that the fluid speed can not increase effectively and make the air hotter quickly due to the spindle channel height have limit. To sum up the design of special channels is unnecessary.
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Chen, Huang-Chi, und 陳皇吉. „The influence of heat treatment strength on Cr-Mo steel -A case study of bicycle spindle“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/06961999969993070417.
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碩士國立中興大學
機械工程學系所
96
Heat treatment process is often used to improve mechanical properties of components. Various heat treatment processes have different influences on material. This paper is to show the influences of strength on Cr-Mo Steel between austempering and quenching-tempering heat treatment processes, with the use of bicycle spindles as the experimental subject. During the experiment austempering process involves 860℃ austenizing temperature.360℃ austempering. And 60-minute austempering time condition. An average maximum load of 6363.67kg was achieved, resulting 65901.33kg-mm total torque. Other hand, quenching- tempering heat treatment process involves 880℃ quenching temperature, tempering at 530℃, for 20-minute tempering criteria. Maximum load, in average, was 4605kg, resulting 50559.67kg-mm total torque. After comparing the experiment data gathered between Austempering and quenching- tempering processes, we discover that austempering results 1758.67kg increase in maximum load. The increase was about 38.2%. Results 15341.66kg-mm increase in total torque. The increase was about 30.34% Therefore, a Cr-Mo Steel bicycle spindle with austempering heat treatment can have better strength in terms of maximum load and total torque. During the experiment minimum deformation involves 760℃ austenizing temperature.200℃ austempering. And 3.85mm thickness of spindle condition. An average minimum deformation of 1.08mm was achieved, the increase was 0.81mm than before heat treatment.