New Investigation on the Geometry of the Contact in Gear Generation

2003 ◽  
Author(s):  
Marco Gabiccini ◽  
Massimo Guiggiani ◽  
Francesca Di Puccio
Keyword(s):  
Reference Frame ◽  
Relative Position ◽  
Geometric Approach ◽  
Gear Ratio ◽  
Reference Systems ◽  
Geometric Properties ◽  
Envelope Surface ◽  
Enveloping Surface ◽  
Contact Matrix

Based on a recently developed geometric approach to the theory of gearing that does not make use of any reference systems [1], this paper presents some useful relations between the geometric properties of the enveloping surface and those of its envelope. Treating vectors as such, that is without expressing their components in any reference systems, it is possible to obtain compact expressions for the coefficients of the first and second fundamental forms of the envelope surface. These coefficients show to be central in the determination of the contact matrix between mating surfaces. Moreover, since this approach is coordinate free, it is valid regardless of the reference frame actually employed to perform calculations and allows a, hopefully, clearer understanding of the roles played by the intrinsic geometric properties of the enveloping surface, the relative position of the gear axes and the gear ratio.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

scholarly journals Observing UT1-UTC with VGOS

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Rüdiger Haas ◽  
Eskil Varenius ◽  
Saho Matsumoto ◽  
Matthias Schartner
Keyword(s):  
Standard Deviation ◽  
Reference Frame ◽  
Earth Rotation ◽  
Space Observatory ◽  
International Earth Rotation ◽  
Onsala Space Observatory ◽  
X Band ◽  
First Results

AbstractWe present first results for the determination of UT1-UTC using the VLBI Global Observing System (VGOS). During December 2019 through February 2020, a series of 1 h long observing sessions were performed using the VGOS stations at Ishioka in Japan and the Onsala twin telescopes in Sweden. These VGOS-B sessions were observed simultaneously to standard legacy S/X-band Intensive sessions. The VGOS-B data were correlated, post-correlation processed, and analysed at the Onsala Space Observatory. The derived UT1-UTC results were compared to corresponding results from standard legacy S/X-band Intensive sessions (INT1/INT2), as well as to the final values of the International Earth Rotation and Reference Frame Service (IERS), provided in IERS Bulletin B. The VGOS-B series achieves 3–4 times lower formal uncertainties for the UT1-UTC results than standard legacy S/X-band INT series. The RMS agreement w.r.t. to IERS Bulletin B is slightly better for the VGOS-B results than for the simultaneously observed legacy S/X-band INT1 results, and the VGOS-B results have a small bias only with the smallest remaining standard deviation.

Determination of geometric properties of SNOM tips by means of combined far-field and near-field evaluation

1999 ◽  
Author(s):  
Soenke Seebacher ◽  
Wolfgang Osten ◽  
Werner P. O. Jueptner ◽  
Vadim P. Veiko ◽  
Nikolay B. Voznesensky
Keyword(s):  
Near Field ◽  
Field Evaluation ◽  
Far Field ◽  
Geometric Properties

CuAAC and RuAAC with Alkyne-functionalised Dihydroazulene Photoswitches and Determination of Hammett σ-Constants for Triazoles

2014 ◽  
Vol 67 (3) ◽  
pp. 531 ◽  
Author(s):  
Henriette Lissau ◽  
Søren Lindbæk Broman ◽  
Martyn Jevric ◽  
Anders Ø. Madsen ◽  
Mogens Brøndsted Nielsen
Keyword(s):  
Molecular Electronics ◽  
Ring Closure ◽  
Reference Systems ◽  
Rigid Structure ◽  
Useful Components ◽  
Substituent Constants ◽  
Hammett Σ Constants

Dihydroazulene (DHA)–vinylheptafulvene (VHF) photoswitches have attracted attention as potentially useful components in molecular electronics. The π-conjugated dihydroazulene system is a rigid structure and can be strategically functionalised to place handles for further elaboration. Here we show that alkyne-functionalised dihydroazulenes can be subjected to copper and ruthenium catalysed azide–alkyne cycloadditions (CuAAC and RuAAC) with tolylazide, furnishing 1,4- and 1,5-disubstituted triazoles. The rates of ring-closure of the corresponding vinylheptafulvenes were compared with those of reference systems, which allowed determination of Hammett substituent constants (meta and para) for N-tolyl-substituted 1,2,3-triazoles.

scholarly journals Analytical Study of the Process of Sowing Seeds of Conifers by Pin Sowing Unit

2017 ◽  
Vol 7 (3) ◽  
pp. 201-210
Author(s):  
Игорь Казаков ◽  
Igor' Kazakov ◽  
Владимир Казаков ◽  
Vladimir Kazakov
Keyword(s):  
Research Process ◽  
Forest Tree ◽  
Gear Ratio ◽  
Technological Parameters ◽  
Seeding Rate ◽  
Coniferous Species ◽  
Analytical Research ◽  
Forest Nurseries ◽  
Sowing Machine

The cultivation of seedlings in forest tree nurseries for reforestation and afforestation is an important task of forestry. For sowing seeds of coniferous species in forest nurseries seeder with coil sowing machines are used, which do not provide the desired uniformity of seeding and damage seeds when sowing. Pin sowing machines allow you to eliminate these drawbacks, so research process is interested for forestry. As a result of the research of the process of sowing seeds of conifers by sowing machines with pin metering apparatus, formulas for determination of its angular velocity and rotational speed of the drive of furrow making roller. Formulas to determine seeding rate are proposed, taking into account constructive parameters of seeding machine and size of pins. It is noted that the increase in height and width of pins and also fill factor and number of rows of pins leads to the increase in standards; and increase in gear ratio of the actuator causes its decrease. Uneven supply of seed increases with increased size of pins, so thickness of pins is recommended to be minimum one, taking into account its sufficient strength. Conducted analytical research of the process of work of pin sowing unit enabled to obtain the necessary expressions for calculating structural and technological parameters of the forest sowing machine for sowing seeds of coniferous species in forest nurseries.

scholarly journals INFLUENCE OF CONSTRUCTIVE AND TECHNOLOGICAL PARAMETERS OF THE UNIT FOR STRIP TILL ON THE LUMPINESS

2020 ◽  
Author(s):  
G. Golub ◽  
◽  
A. Dvornyk
Keyword(s):  
Winter Wheat ◽  
Relative Position ◽  
Experimental Studies ◽  
Movement Speed ◽  
Technological Parameters ◽  
Depth Of Processing ◽  
Processing Depth ◽  
Economic Methods ◽  
Strip Tillage

The goal of the work. Investigate the influence of the relative position of the depth of processing with a chisel, the speed of movement of the unit and the distance between the cutting side discs on the lumpiness of the processed strip. Methods of research: analytical - quantitative determination of the quality of strip tillage; laboratory-field - for research, an experimental installation was completed with an MTZ-892 tractor and a section of the unit for strip tillage; statistical with generally accepted agronomic and economic methods. Results. Experimental studies of changes in the design and technological parameters of the unit for strip processing with the determination of lumpiness have been carried out. To study the main parameters, the depth of processing of the subsoiler (chisel) is taken from 13 to 27 cm, the distance between the cutting side discs is from 10 to 30 cm, the speed of the MTA is from 4 to 11 km/h. Unchanged parameters during the study: the distance from the axis of the front disc to the chisel is 50 cm, the distance from the chisel to the axis of the cutting side discs is 50 cm, the immersion depth of the cutting side discs is 10 cm. Experimental background is winter wheat stubble. Soil cultivation for winter wheat - deep (18 cm) disking, before that plowing to a depth of 25 cm. According to the research results, graphs of the dependence of lumpiness on the relative position of the chisel, cutting side discs and changes in the speed of the MTA were built. As the speed and distance between the side cutting discs increase, the lumpiness value decreases. Conclusions. Based on the results of the studies, the dependences of lumpiness on the relative position of the chisel and cutting side disks were obtained when the speed of the MTA was changed. It was determined that with an increase in the processing depth, the distance between the cutting side discs of 20 cm and the MTA movement speed of 7.5 km / h, a uniform increase in lumpiness is observed. The distance between the side cutting discs of 10 cm is not suitable for work.

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