Pressure angle

About: Pressure angle is a research topic. Over the lifetime, 1373 publications have been published within this topic receiving 10245 citations. The topic is also known as: angle of obliquity.

Efficiency of Nonstandard and High Contact Ratio Involute Spur Gears

Abstract: A power loss prediction was extended to include involute spur gears of nonstandard proportions. The method is used to analyze the effects of modified addendum, tooth thickness, and gear center distance in addition to the parameters previously considered which included gear diameter, pitch, pressure angle, face width, oil viscosity, speed, and torque. Particular emphasis was placed on high contact ratio gearing (contact ratios greater than two). Despite their higher sliding velocities, high contact ratio gears are designed to levels of efficiency comparable to those of conventional gears while retaining their advantages through proper selection of gear geometry.

Evolution of the angle of obliquity of the femoral diaphysis during growth--correlations.

Abstract: Numerous studies of the bicondylar angle of the adult femur have been carried out in human anatomy, paleoanthropology and primatology. The aim of this paper is to study the evolution of this angle in relation to age and acquisition of walking in young children. Seventy-seven radiographs of children, ranging from 5 months to 17 years postnatally, and of four dead newborn were analysed. The measurements concern the bicondylar angle (A.O.F.), the collo-diaphyseal angle (A.C.D.), the length of the femoral neck (L.N.) and of the femur (L.F.) and the interacetabular distance (D.I.A.). Some children were x-rayed at different ages, which permits a longitudinal as well cross-sectional study. The results show that there is no sexual dimorphism and that the increase in the angle is closely related to the age of the child. The bicondylar angle starts at 0° at birth and then increases progressively with growth to reach adult values of at least 6°-8° between 4 and 8 years postnatally. In adults, the mean values are between 8° and 11° and the maximum range is between 6° and 14°. The obliquity angle corresponds to an angular remodeling of the femoral diaphysis, which is independant of the growth and shape of the distal femoral epiphysis. The tibio-femoral angle measures the evolution of a physiologic phenomenon, from the load “in varus” to the load “in valgus” of the lower limb. It is linked with the bicondylar angle but is different from it.

Low noise gearing

Abstract: A gear tooth form is disclosed that maximizes the profile (transverse) contact ratio for coplanar axis gearing. As the tooth form allows teeth two or three times as fine as those of conventional involute gearing to be used without loss of torque capacity, the face (axial) contact ratio for helical or spiral bevel gearing is also maximized. The total contact ratio (profile plus face contact ratios) is therefore maximized, and the torque load is divided over the maximum number of teeth. This minimizes the transmission error, which in turn minimizes operating noise and vibration. The gearing employs a minimum pressure angle and a path of contact that includes a curved portion.

Maximum Fillet Stress Analysis Based on Load Sharing in Normal Contact Ratio Spur Gear Drives

Abstract: An optimum design of high-quality gears requires an accurate estimation of the tooth load. Since only a fraction of the total load is shared by each pair, when there is contact in more than one pair during transmission, the same has been estimated with a reasonable accuracy through the load-sharing ratio calculated using the single-point loaded model. The reliability of this method has also been justified by comparison with multipair contact models and also by checking with the values available in the literature. The influence of finite-element modeling, boundary conditions, gear ratio, teeth number, module, pressure angle at pitch circle, backup ratio, generating rack cutter tip radius, and addendum modification factor on the load-sharing ratio and in turn in the maximum fillet stress has been studied and discussed using single-point loaded model of normal contact ratio gear pairs in this study.