The design and analysis of single flank transmission error tester for loaded gears

To strengthen the understanding of gear transmission error and to verify mathematical models which predict them, a test stand that will measure the transmission error of gear pairs under design loads has been investigated. While most transmission error testers have been used to test gear pairs under unloaded conditions, the goal of this report was to design and perform dynamic analysis of a unique tester with the capability of measuring the transmission error of gears under load. This test stand will have the capability to continuously load a gear pair at torques up to 16,000 in-lb at shaft speeds from 0 to 5 rpm. Error measurement will be accomplished with high resolution optical encoders and the accompanying signal processing unit from an existing unloaded transmission error tester. Input power to the test gear box will be supplied by a dc torque motor while the load will be applied with a similar torque motor. A dual input, dual output control system will regulate the speed and torque of the system. This control system's accuracy and dynamic response were analyzed and it was determined that proportional plus derivative speed control is needed in order to provide the precisely constant torque necessary for error-free measurement

The design and analysis of single flank transmission error testor for loaded gears

Due to geometrical imperfections in gears and finite tooth stiffnesses, the motion transmitted from an input gear shaft to an output gear shaft will not have conjugate action. In order to strengthen the understanding of transmission error and to verify mathematical models of gear transmission error, a test stand that will measure the transmission error of a gear pair at operating loads, but at reduced speeds would be desirable. This document describes the design and development of a loaded transmission error tester. For a gear box with a gear ratio of one, few tooth meshing combinations will occur during a single test. In order to observe the effects of different tooth mesh combinations and to increase the ability to load test gear pairs with higher gear ratios, the system was designed around a gear box with a gear ratio of two

Professional Role Attitudes and Decision-making in Medication Administration

This is a case study of nurses\u27 attitudes toward professional nurse role factors affecting decision-making in medication administration. This chapter includes an introduction to the problem, a statement of the problem, objectives of the study, the significance of the problem, definitions of terms pertinent to this study, variables and their operational definitions, and a summary statement. The objectives of this study are to examine five selected role attitudes of nurses that may affect the specific decisions involved in floor stock system medication administration procedures. These selected role attitudes are frequency, complexity, importance, discretion, and search intensity. The theoretical and methodological frameworks utilized in this study, as well as the role attitude variables, are based on a previous study done by Hinshaw

Early Settlement of Portuguese America

The Portuguese Empire expanded over five continents and endured for nearly six centuries. Beginning with small forts and trading posts in Africa in the early fifteenth century to the formal handover of Macau to China in 1999, Portugal reigned over one of the longest lasting modern empires in the world.  The Portuguese foray into the Americas was with the colony of Brazil and was a happenstance because a Portuguese captain accidentally landed in South America.  What ensued was limited claims, multiple attacks from other European Empires, and the Portuguese quickly establishing the Donatary Captaincy system to colonize Brazil.  This system of colonization was successful in the small Atlantic Islands the Portuguese colonized decades before, but was a near complete failure in Brazil. This paper shows how the Donatary Captaincies failed because of four reasons: (1) the decision to use Donatary Captaincies was reactionary; (2) individual captains assumed the initial capital cost of colonization without surplus to maintain their claims; (3) there were no residency laws for captains to be in the colonies; and (4) continual defensive attacks by indigenous populations hindered colonial growth. By providing the historical background and planning decisions about early Portuguese America, the entire story of “discovery” through Donatary Captaincies to a singular Governorate General adds to the understanding of early Portuguese colonization in Brazil.  This paper contributes to the literature by providing a review of secondary sources regarding the early Portuguese colonization through the lens of built environment in English