Effects of geometric parameters on static load capacity of a double-row four-point contact ball bearing

2013 ◽  
Vol 27 (4) ◽  
pp. 1053-1061 ◽  
Author(s):  
Guanci Chen ◽  
Ping Jia ◽  
Jianqiang He
Keyword(s):  
Ball Bearing ◽  
Static Load ◽  
Load Capacity ◽  
Point Contact ◽  
Geometric Parameters ◽  
Double Row

scholarly journals Optical Analysis of Ball Bearing Starvation

1971 ◽  
Vol 93 (3) ◽  
pp. 349-361 ◽  
Author(s):  
L. D. Wedeven ◽  
D. Evans ◽  
A. Cameron
Keyword(s):  
Film Thickness ◽  
Ball Bearing ◽  
Point Contact ◽  
Experimental Measurements ◽  
Line Contact ◽  
Optical Analysis ◽  
Grease Lubrication ◽  
Theoretical Predictions ◽  
Pressure Stress ◽  
Starvation Conditions

Elastohydrodynamic oil film measurements for rolling point contact under starvation conditions are obtained using optical interferometry. The experimental measurements present a reasonably clear picture of the starvation phenomenon and are shown to agree with theoretical predictions. Starvation inhibits the generation of pressure and, therefore, reduces film thickness. It also causes the overall pressure, stress, and elastic deformation to become more Hertzian. Additional experiments using interferometry illustrate: the cavitation pattern, lubricant entrapment, grease lubrication, ball spin, and edge effects in line contact.

Quantitative Analysis of Inner Force Distribution and Load Capacity of Grasps and Fixtures

2002 ◽  
Vol 124 (2) ◽  
pp. 444-455 ◽  
Author(s):  
Youlun Xiong ◽  
Han Ding ◽  
Michael Yu Wang
Keyword(s):  
Quantitative Analysis ◽  
System Design ◽  
Load Capacity ◽  
Point Contact ◽  
Analytical Description ◽  
Engineering Practice ◽  
Force Distribution ◽  
Grasp Planning ◽  
Analysis And Design ◽  
Fixture System

This paper focuses on a quantitative analysis for grasp planning and fixture design based on an analytical description of point contact restraint. In the framework, the analysis deals with the fundamental concepts of restraint cone, freedom cone, force-determinacy and relative form closure. A method is presented to quantify the performance of a fixture (or grasp) with two major characteristics of inner force distribution and load capacity. Two different fixturing (or grasp) models of simplex grasp and elastic grasp are presented. It is shown that the performance of these two types of grasp (or fixturing) could be measured with different performance indices. A minimax index (MMI) and a volume measure are defined for evaluating a simplex grasp, while a measure using the tolerable range of differential motion in the twist space or the allowable load polyhedron in the wrench space would be suitable for quantifying robustness and load capability of an elastic fixture system. Furthermore, for fixture system design a geometric analysis and reasoning procedure is described for the design of locators, clamps and supplementary supports. The aim of these proposed analysis and design techniques is to provide a scientific foundation for automated grasping/fixturing system design in the engineering practice.

Load Capacity of an Internal Slab-Column Connection depending on the Geometric Parameters of the Reinforcement

2014 ◽  
Vol 969 ◽  
pp. 234-240 ◽  
Author(s):  
Barbara Wieczorek
Keyword(s):  
Laboratory Tests ◽  
Load Capacity ◽  
Geometric Parameters ◽  
Simplified Model

Literature deals with a score of catastrophes of slab-column structures, where the absence of adequately constructed reinforcement resulted in an absolute destruction of the construction. This problem is not dealt with either in the Polish Standards, nor in the Eurocodes. Some suggestions concerning the prevention of such situations are to be found merely in CSA A23.3-04. Instructions concerning such a structure are also contained in ACI 318. The paper presents the results of laboratory tests performed on a simplified model of a slab-column connection. The aim of investigations was to find out at which value of the load the destruction of such a connection occurs due to a rupture of the bars above the column. In respective models the reinforcement passing above the column consisted of bars with a diameter of ø8 mm, ø12 mm or ø16 mm. The obtained results of laboratory tests and calculations permitted to determine the relations between the exerted load and the displacement of the column in time and also to determine the values of the force at which the rupture of the bars above the column had taken place.

A Novel 1-DOF Deployable Mechanism for Parabolic Cylindrical Surface Approximation

2019 ◽  
Author(s):  
Hang Xiao ◽  
Shengnan Lu ◽  
Xilun Ding
Keyword(s):  
Cylindrical Surface ◽  
Static Load ◽  
Geometric Parameters ◽  
Surface Approximation ◽  
Magnification Ratio ◽  
Load Analysis ◽  
Deployable Mechanism

Abstract This paper presents a novel deployable mechanism for approximating the parabolic cylindrical surface. The proposed mechanism, which can deploy and fold synchronously in the radial and axial directions, is constructed by double four-bar linkages and scissor linkages. In the fully deployed configuration, the mechanism can approximate a cylindrical surface. It can also be folded compactly into a bundle. The radial and axial deployable mechanisms are described and their position kinematics are solved. A synchronous mechanism is designed to ensure the synchronous movement of the radial and axial mechanisms. Geometric parameters of the mechanism for approximating a given parabolic cylindrical surface are obtained. The magnification ratio of the designed mechanism is calculated. The best choice of actuator is determined through static-load analysis.

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