A method for static and dynamic load analysis of standard and modified spur gears

The mesh stiffness and dynamic load characteristics for several cases of the Normal Contract Ratio and High Contact ratio gearing. The considered contact ratios were grouped in the general range of 1.7,2.0, and 2.3. The HCR gearing is defined by contact ratios equal to or greater than 2.0. The HCR gearing is represented by a group of small pressure angle, fine pitch, and long addendum gearing

Conceptual design of a fixed-pitch wind turbine generator system rated at 400 kilowatts

The design and cost aspects of a fixed pitch, 400 kW Wind Turbine Generator (WTG) concept are presented. Improvements in reliability and cost reductions were achieved with fixed pitch operation and by incorporating recent advances in WTG technology. The specifications for this WTG concept were as follows: (1) A fixed pitch, continuous wooden rotor was to be provided by the Gougeon Bros. Co. (2) An 8 leg hyperboloid tower that showed promise as a low cost structure was to be used. (3) Only commercially available components and parts that could be easily fabricated were to be considered. (4) Design features deemed desirable based on recent NASA research efforts were to be incorporated. Detailed costs and weight estimates were prepared for the second machine and a wind farm of 12 WTG's. The calculated cost of energy for the fixed pitch, twelve unit windfarm is 11.5 cents/kW hr not including the cost of land and access roads. The study shows feasibility of fixed pitch, intermediate power WTG operation

Wie bunt und lustig kann der Text der Aufgabe sein und wozu soll es gut sein?

Das allmächtige Leben weiß über alles Bescheid. Es bedarf eigentlich keinem Beweis, weil es wir alle nur zu gut Bescheid wissen, dass es eigentlich alles, was entsteht, im Leben verschmolzen ist. Somit erscheint das Leben sogar mächtiger als die Statistik, die nur über Vieles Bescheid weiß. Leider ist das allwissende Leben nicht etwas, dass gleich etwas andeutet oder erklärt. So müssen wir selbst viele Antworte im Kopf haben, im Leben entdecken oder aus den Büchern entnehmen

Dynamics of early planetary gear trains

A method to analyze the static and dynamic loads in a planetary gear train was developed. A variable-variable mesh stiffness (VVMS) model was used to simulate the external and internal spur gear mesh behavior, and an equivalent conventional gear train concept was adapted for the dynamic studies. The analysis can be applied either involute or noninvolute spur gearing. By utilizing the equivalent gear train concept, the developed method may be extended for use for all types of epicyclic gearing. The method is incorporated into a computer program so that the static and dynamic behavior of individual components can be examined. Items considered in the analysis are: (1) static and dynamic load sharing among the planets; (2) floating or fixed Sun gear; (3) actual tooth geometry, including errors and modifications; (4) positioning errors of the planet gears; (5) torque variations due to noninvolute gear action. A mathematical model comprised of power source, load, and planetary transmission is used to determine the instantaneous loads to which the components are subjected. It considers fluctuating output torque, elastic behavior in the system, and loss of contact between gear teeth. The dynamic model has nine degrees of freedom resulting in a set of simultaneous second order differential equations with time varying coefficients, which are solved numerically. The computer program was used to determine the effect of manufacturing errors, damping and component stiffness, and transmitted load on dynamic behavior. It is indicated that this methodology offers the designer/analyst a comprehensive tool with which planetary drives may be quickly and effectively evaluated

Pertanian dalam Perspektif Al-Qur’an

Agriculture is the activity of raising crops and livestock on a plot of land, without causing the land to be damaged for further production. Besides that, agriculture cannot be separated from plants grown by humans, but growth cannot be separated from the intervention of Allah SWT. Because the Qur'an is a book of guidance for humans in all matters, whose authenticity is guaranteed. Indeed, the Qur'an is not a scientific book, but a religious book. Even so, it cannot be denied that it contains many natural cues. The Qur'an contains verses that discuss science, including agriculture, which are very numerous. Therefore, in this study, the author tries to reveal interpretations related to these verses. The results of this study show that by studying the Koran we are able to explain verses about agriculture in a comprehensive manner, even explaining different things about agriculture in one verse or a combination of verses. Besides that, we can also know about different soil conditions, therefore by studying Agriculture it is necessary to understand agriculture in the context of the Qur'an as a guide for mankind in the world and in the hereafter. Thus, these blessings will bring good agricultural results. overflow

A multi-purpose method for analysis of spur gear tooth loading

A large digitized approach was developed for the static and dynamic load analysis of spur gearing. An iterative procedure was used to calculate directly the "variable-variable" gear mesh stiffness as a function of transmitted load, gear tooth profile errors, gear tooth deflections and gear hub torsional deformation, and position of contacting profile points. The developed approach can be used to analyze the loads, Hertz stresses, and PV for the normal and high contrast ratio gearing, presently the modeling is limited to the condition that for a given gear all teeth have identical spacing and profiles (with or without surface imperfections). Certain types of simulated sinusoidal profile errors and pitting can cause interruptions of the gear mesh stiffness function and, thus, increase the dynamic loads in spur gearing. In addition, a finite element stress and mesh subprogram was developed for future introduction into the main program for calculating the gear tooth bending stresses under dynamic loads