scholarly journals Analysis of Gear Wheel-shaft Joint Characterized by Comparable Pitch Diameter and Mounting Diameter

10.14311/472 ◽  
2003 ◽  
Vol 43 (5) ◽  
Author(s):  
J. Ryś ◽  
H. Sanecki ◽  
A. Trojnacki
Keyword(s):  
Carrying Capacity ◽  
Small Difference ◽  
Design Procedure ◽  
Gear Wheel ◽  
Combined Loading ◽  
Strength Analysis ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Load Intensity ◽  
New Generation

This paper presents the design procedure for a gear wheel-shaft direct frictional joint. The small difference between the operating pitch diameter of the gear and the mounting diameter of the frictional joint is the key feature of the connection. The contact surface of the frictional joint must be placed outside the bottom land of the gear, and the geometry of the joint is limited to the specific type of solutions.The strength analysis is based on the relation between the torque and statistical load intensity of the gear transmission. Several dimensionless parameters are introduced to simplify the calculations. Stress-strain verifying analysis with respect to combined loading, the condition of appropriate load-carrying capacity of the frictional joint and the fatigue strength of the shaft are applied to obtain the relations between the dimensions of the joint and other parameters. The final engineering solution may then be suggested. The approach is illustrated by a numerical example.The proposed procedure can be useful in design projects for small, high-powered modern reducers and new-generation geared motors, in particular when manufactured in various series of types.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

Improvement of Regulatory Calculation of the Load-Carrying Capacity of Vibrated, Centrifuged, and Vibrocentrifuged-Based Iron-Concrete Columns with Variatropic Structure

2020 ◽  
pp. 78-84
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
А. А. Чернильник
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
Strength Analysis ◽  
Load Carrying Capacity ◽  
Load Bearing Capacity ◽  
Load Carrying ◽  
Regulatory Approach ◽  
Concrete Elements

Состояние проблемы. Сжатые железобетонные элементы изготавливаются по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что соответствует действительности лишь в вибрированных колоннах. Результаты. Разработан усовершенствованный нормативный подход к расчету прочности центрифугированных и виброцентрифугированных железобетонных колонн, заключающийся в использовании в расчете интегральных или дифференциальных характеристик бетона. Выводы. Расчет прочности коротких центрально сжатых вибрированных, центрифугированных и виброцентрифугированных колонн по усовершенствованному нормативному подходу дал наилучшие результаты с использованием дифференциальных характеристик бетона, различающихся по сечению. Statement of the problem. Compressed reinforced concrete elements are manufactured according to three main technologies - vibrating, centrifuging and vibrocentrifugation. However, all the main calculated dependences for determining their load-bearing capacity were derived based on the main postulate - the constancy and equality of the characteristics of concrete over the cross section, which corresponds to reality only in vibrated columns. Results. An improved regulatory approach has been developed for calculating the strength of centrifuged and vibrocentrifuged reinforced concrete columns, which involves using the calculation of integral or differential characteristics of concrete. Conclusions. Strength analysis of short centrally compressed vibrated, centrifuged and vibrocentrifuged columns using an improved regulatory approach yielded the best results using differential characteristics of concrete varying in cross section.

Structural Kinematics of Partially-Parallel Robotic Mechanisms

1987 ◽  
Author(s):  
M. Gaber Mohamed
Keyword(s):  
Carrying Capacity ◽  
Kinematic Chain ◽  
Performance Criteria ◽  
Load Carrying Capacity ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Load Carrying ◽  
Parallel Kinematic ◽  
New Generation ◽  
Robotic Applications

Abstract This paper introduces a new generation of robotic mechanisms. Such mechanisms are intermediate between the familiar serial and the fully-parallel robotic mechanisms. They usually comprise several subassemblies that are serially connected to one another. Each subassembly is basically an over constrained fully parallel kinematic chain. Such mechanisms are called “Partially-Parallel Robotic Mechanisms.” A type synthesis of planar and spatial partially-parallel robotic mechanisms is performed. Several practical designs are then introduced and studied for future robotic applications. Several performance criteria of this type of mechanisms are discussed and compared with those of serial as well as fully-parallel robotic mechanisms. Partially-parallel mechanisms are superior than serial mechanisms in rigidity, strength precision positioning and load carrying capacity. Furthermore, they are relatively less complex and have larger range of motion than fully-parallel mechanisms.

Buckling of Short, Thin-Walled Cylinders Under Combined Loading

1991 ◽  
Vol 113 (4) ◽  
pp. 306-311 ◽  
Author(s):  
P. Goltermann
Keyword(s):  
Yield Stress ◽  
Carrying Capacity ◽  
Critical Stress ◽  
Plate Theory ◽  
Yield Condition ◽  
Offshore Structures ◽  
Combined Loading ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Actual Geometry

Short cylindrical shells are often used in offshore structures. Such cylinders are loaded by axial compression as well as hydrostatical pressure. The load-carrying capacity is for practical purposes determined for each of the two load cases separately. The determination of the load-carrying capacity for a combined loading is then based on a combination of those two load-carrying capacities. This combination differs from code to code and has a significant influence on the load-carrying capacity. This paper presents a rational way of estimating the capacity by using simple, well-known theories. The elastic, critical stress (fe) of a perfect cylinder is estimated according to the classic shell theory for the two load cases, and the respective knock-down factors (α) are calculated according to a code or according to Koiter’s classic stability theory. This leads to an estimate of the ratio between actual stress and the elastic, critical stress (fe·α) of the imperfect cylinder in the two load cases. The membrane stresses and the bending stresses due to the oval imperfection of the cylinder are calculated according to the plate theory, in which the stiffness is reduced corresponding to those ratios. The capacity is defined as the load level at which a point yields according to von Mises’ yield condition. The method is easily applicable for practical purposes and has the advantage that it estimates the capacity at the actual geometry, yield stress, imperfection level and load combination, and thus enables a better estimation. The paper shows that the interaction curves depend severely on the geometry, the level of imperfection, and the size of the yield stress.

An Assessment on the Plastic Capacity of Pipe-in-Pipe Systems Under Damage Progression Effect

2021 ◽  
Vol 88 (4) ◽  
Author(s):  
Farhad Davaripour ◽  
Bruce W.T. Quinton ◽  
Kenton Pike
Keyword(s):  
Carrying Capacity ◽  
Phase 1 ◽  
Lateral Load ◽  
External Pressure ◽  
Combined Loading ◽  
Load Carrying Capacity ◽  
Plastic Damage ◽  
Damage Progression ◽  
Structural Resistance ◽  
Load Carrying

Abstract In recent years, pipe-in-pipe (PiP) systems have been employed in an increasing number of subsea projects. According to the previous studies, the external pressure required to develop the initial local buckle on the PiP system is significantly higher than the pressure required to propagate the buckle along the system. In this respect, it is reasonable to investigate a novel topic where the propagation of buckle is induced by a lateral interference load instead of external pressure (e.g., diagonal fishing gear impact). On this subject, the recent studies showed the progression of plastic damage along a single-walled pipe, which is induced by a lateral load, could significantly lower the load-carrying capacity of the pipe. The present study investigates this finding for a PiP solution under a two-phase loading condition: in phase 1, the PiP solution is subject to 75 mm perpendicular indentation, and in phase 2, the resulting plastic damage in phase 1 is translated and induced longitudinally along with the PiP system. Furthermore, using finite element analyses, the effect of combined loading (axial and lateral load) on the load-carrying capacity of the PiP specimen is investigated. The test results show that upon the initiation of damage progression, the load-carrying capacity of the PiP specimen (against the lateral indentation) declines by 10%. Also, the numerical results show that the structural resistance of a PiP specimen against a lateral indentation drops significantly when the inner pipe is subject to axial compression.

scholarly journals Automation of gearbox design

2021 ◽  
Author(s):  
Marius Fürst ◽  
Joshua Götz ◽  
Michael Otto ◽  
Karsten Stahl
Keyword(s):  
Carrying Capacity ◽  
Early Stage ◽  
Analytical Calculation ◽  
Gear Wheel ◽  
Gear Train ◽  
Mixed Integer ◽  
Load Carrying Capacity ◽  
Time Saving ◽  
Stage Of Development ◽  
Load Carrying

AbstractIn order to respond to a shortened development time of today’s transmission systems, the automation of certain steps in the design process is essential for ensuring an efficient development process. Computer-aided tools are widely used for analyzing given design configurations because standardized methods are available to evaluate the load carrying capacity of all key components of a simple gear train, namely bearings, shafts and gears. At an early stage of development, requirements and restrictions need to be synthesized to design concepts. During this step, engineers typically rely on their experience and proven practice. Design optimization usually is achieved through an iterative and time-consuming process of analyzing and tuning towards an optimization objective. In this paper a time-saving, automated and systematic method for the design of weight optimized helical gearboxes is proposed. The underlying method has been derived from both, norms and guidelines, which exist for the design and layout of shafts, bearings and gear wheel bodies. Starting with only few input parameters, a detailed shaft geometry with different diameter sections can be derived. A discrete set of values from standard tables and rolling bearing catalogs represents the method’s framework for all realizable shaft diameters in each section. A mixed integer nonlinear optimization problem results from the interdependence between these distinct values. For this purpose, a systematic iterative approach has been developed and implemented in an established design program for gearbox systems. The algorithm uses the results drawn from an analytical calculation of the shaft load carrying capacity to directly adjust the shaft’s diameter and length values. The dimensioning of the wheel body, the service life calculation of rolling element bearings and the selection of specific machine elements are embedded in a systematic sequence. As a result, the model is capable to work out a weight-optimized gearbox that consists of gear meshes, shafts and bearings, taking all three components into consideration at a time.

Optimum Surface Profile for the Enclosed Pocket Hydrodynamic Gas Thrust Bearing

1970 ◽  
Vol 92 (2) ◽  
pp. 318-324 ◽  
Author(s):  
C. Y. Chow ◽  
H. S. Cheng ◽  
D. F. Wilcock
Keyword(s):  
Finite Difference Method ◽  
Carrying Capacity ◽  
Geometrical Parameter ◽  
Thrust Bearing ◽  
Surface Profile ◽  
Design Procedure ◽  
Load Carrying Capacity ◽  
Relative Importance ◽  
Load Carrying ◽  
The Finite Difference Method

The relative importance, with respect to load-carrying capacity, of each geometrical parameter in a self-lubricated thrust bearing, with an enclosed pocket, is examined at Λ = 0.55. The bearing geometries, including the pocket configurations, for three types of film profiles are optimized. The film profiles in the pocket considered are flat-step, tapered, and taper-step, Fig. 1. Of these three profiles of film, the taper-step film, in an enclosed-pocket bearing, offers the best load-carrying capacity. The variations of load versus each geometrical parameter are shown graphically to facilitate design procedure. These results are obtained from the solution of Reynold’s equation for a compressible fluid film as approximated by the finite-difference method [5]. The load-carrying capacity of an enclosed-pocket bearing with taper-step profile can be significantly higher than that of a bearing with the spiral-grooved pattern under the conditions investigated.

Design methodology for monolithic layer radial passive magnetic bearing

2018 ◽  
Vol 233 (6) ◽  
pp. 992-1000
Author(s):  
Lijesh K Parambil
Keyword(s):  
Carrying Capacity ◽  
Design Methodology ◽  
Design Procedure ◽  
Single Layer ◽  
Maximum Load ◽  
Magnetic Bearing ◽  
Computational Time ◽  
Load Carrying Capacity ◽  
Straightforward Method ◽  
Load Carrying

Passive magnetic bearings (PMBs) are considered to be one of the economical and effective methods for levitating two surfaces in relative motion. This obviates the use of lubrication, provides zero wear, and negligible friction, thereby making the operation maintenance free. Due to these advantages, the modeling and design of the PMBs were given substantial importance in many studies. However, a well-defined designing procedure to achieve desired load carrying capacity for the given space constraints for the intended PMB application is yet to be established. Prior studies were performed on PMBs for achieving maximum load carrying capacity, but no design methodology was proposed that could facilitate easier design of a PMB in lesser computational time. In the present work, a very effective and a straightforward method is proposed to design a PMB for its paramount output. For this, dimensions of PMBs from the literature are considered for analysis and a set of equations are proposed for the determination of mean radius, axial length, and clearance for a given inner and outer radii of single layer PMBs. Finally, an equation is provided for estimating the load carrying capacity for the determined dimensions of PMB from the proposed design procedure. The effectiveness of the proposed methodology is demonstrated by considering the dimensions of PMBs from 10 literature.

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