Fixturing analysis methods for calculating the contact load distribution and the valid clamping regions in machining processes

2005 ◽  
Vol 29 (5) ◽  
pp. 426-435 ◽  
Author(s):  
H.T. Sánchez ◽  
M. Estrems ◽  
F. Faura
Keyword(s):  
Load Distribution ◽  
Contact Load ◽  
Machining Processes ◽  
Analysis Methods

A novel approach to predict the precision sustainability of ball screw under multidirectional load states

2020 ◽  
pp. 095440622094323
Author(s):  
Jiajia Zhao ◽  
Mingxing Lin ◽  
Xianchun Song ◽  
Yanfeng Zhao ◽  
Nan Wei
Keyword(s):  
Elastic Deformation ◽  
Load Distribution ◽  
Contact Load ◽  
Ball Screw ◽  
Deformation Model ◽  
Load Model ◽  
Novel Approach ◽  
Position Precision ◽  
The Relationship ◽  
Load State

The accurate model of the load state for all balls under multidirectional load is very helpful for the design process of ball screws. The contact deformation model of the ball screw without consideration of the stress difference of all balls is inaccurate. In this paper, a novel contact load model of the ball screw is established by considering coupled axial, radial load to study the elastic deformation displacement and position accuracy. The deviation and variation of axial elastic deformation with the dimension errors of all balls are investigated to obtain the influence of load state on the precision sustainability of the ball screw. The position precision including travel deviation and variation by considering load distribution of all balls is studied under the different load conditions. In addition, a new working bench is designed to study the position precision of the ball screw. The experimental study is carried out to obtain the relationship between the position precision and the contact load state of all balls, which is a reference to compensate for the precision loss of the ball screw.

The Influence of Overlap Coefficient on Contact Behavior of Globoidal Indexing Cam Mechanism

2014 ◽  
Vol 1039 ◽  
pp. 44-51
Author(s):  
Yang Xu Liu ◽  
Shan Ming Luo ◽  
Xue Feng Chang ◽  
Dan Xie
Keyword(s):  
Load Distribution ◽  
Contact Load ◽  
Contact Behavior ◽  
Cam Mechanism ◽  
Overlap Coefficient

An method was proposed to derive the formula of the overlap coefficient and the influence of main parameters on overlap coefficient were also discussed; The load distribution is deduced and the rule of contact load varying with overlap coefficient was revealed; The results indicate that the increasing overlap coefficient can extend the time of rollers engaging, reducing the contact load of globoidal indexing cam mechanism and altering the load distribution.

scholarly journals The Load Distribution of the Main Shaft Bearing Considering Combined Load and Misalignment in a Floating Direct-Drive Wind Turbine

2018 ◽  
Vol 64 ◽  
pp. 07009 ◽  
Author(s):  
Zheng Jingyang ◽  
Ji Jinchen ◽  
Yin Shan ◽  
Tong Van Canh
Keyword(s):  
Wind Turbine ◽  
Friction Force ◽  
Load Distribution ◽  
Great Influence ◽  
Contact Load ◽  
Main Shaft ◽  
Direct Drive ◽  
Angular Misalignment ◽  
Combined Load ◽  
Wind Speeds

The main shaft tapered double-inner ring bearing (TDIRB) of floating direct-drive wind turbine system (FDDWT) is one of the most critical components in FDDWT, and its failure accounts for a large proportion of wind turbine malfunctions and faults. Over the past decades, a significant number of methods have been proposed to calculate the contact load distribution along the roller length in TDIRB, since the contact load distribution of roller is the key factor of fatigue life of TDIRB. Most of methods, however, neglected the misalignment of inner ring with respect to outer ring and friction force. In this paper, with the help of comprehensive and accurate quasi-static mathematical method, the contact load distribution of internal loads in TDIRB are analysed by considering the effects of combined loads, angular misalignment and friction force at different wind speeds for FDDWT. The simulation results show that the amount of combined load has an apparent effect on the contact load distribution along the TDIRB raceways and flanges in both rows. Furthermore, the slight change of tilted misalignment has a great influence on the contact load distribution. In addition, the slight angular misalignment easily produces noncontact zone for the bearing raceway in both rows, which is significantly disadvantage for the external load uniform transmitting to each roller.

Composite Analysis Method of Tooth Contact Load Distribution of Helical Gear

2007 ◽  
Author(s):  
Yoshikazu Miyoshi ◽  
Keiichiro Tobisawa ◽  
Kohei Saiki
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Transmission Error ◽  
Contact Load ◽  
Analysis Method ◽  
Profile Error ◽  
Tooth Contact ◽  
Gear Teeth ◽  
Tooth Flank ◽  
Assembly Error

As demand for the performance improvement of automotive transmission gears increases, gear design is required that achieves high strength, low noise and high efficiency simultaneously. In addition, for high performance it is important not only to select good gear dimensions, but also to improve the tooth contact load distribution which depends on the tooth flank shape and assembly error of the gear pair. Traditional analysis methods calculate the tooth contact load distribution with integral equations that consist of the effect function of bending deflection and that of compressive deformation caused by the contact of gear teeth. However, the complicated integral equations make it difficult to instantly obtain proper results for some tooth flanks distorted by heat treatment and repetition calculation may not converge especially in light load conditions. This paper proposes a new composite analysis method which quickly calculates the tooth contact load distribution of designed or manufactured tooth flanks of helical gears in any load condition. The analytical process consists of three stages: (1) for each flank shape of a gear pair, the three-dimensional relative tooth flank shape is calculated from the actual tooth flank shape and assembly error, and the equivalent tooth profile error of the three-dimensional relative tooth flank shape is obtained by the static deflection which depends on input torque, (2) the static deflection distribution and share load on each line of contact are calculated with the obtained equivalent tooth profile error and the variable stiffness of the involute tooth pair, (3) an integral equation that consists of bending deflection and compressive contact deformation of the gear teeth is solved to obtain the tooth contact load distribution. In practical applications, the tooth contact load distribution is used to output the tooth contact pattern, tooth contact and root bending stresses, and transmission error. The prediction of tooth contact stress and transmission error contributes to the improvement of the pitting strength and gear noise of several transmissions.

Numerical Simulation of Piston Ring in Mixed Lubrication—A Nonaxisymmetrical Analysis

1994 ◽  
Vol 116 (3) ◽  
pp. 470-478 ◽  
Author(s):  
Yuanzhong Hu ◽  
Herbert S. Cheng ◽  
Takayuki Arai ◽  
Yoichi Kobayashi ◽  
Shunichi Aoyama
Keyword(s):  
Film Thickness ◽  
Load Distribution ◽  
Piston Ring ◽  
Mixed Lubrication ◽  
Contact Load ◽  
Asperity Contact ◽  
Static Distortion ◽  
Piston Ring Lubrication ◽  
Cylinder Bore

The assumption of axisymmetry, employed by most of studies on piston ring lubrication, probably gives a too idealistic model for the real situation. A theoretical model for a nonaxisymmetrical analysis of piston ring lubrication has been established in the present study. When a piston ring with an arbitrary free shape is fitted into the cylinder bore, the determination of ring deflection and contact load has been modeled mathematically as a Linear Complementary Problem (LCP). By combining LCP solution with lubrication analysis, the film thickness and contact load distribution over the circumference are obtained, leading to a more realistic simulation for piston ring lubrication. The friction force between piston ring and cylinder bore is predicted by the mixed lubrication model including the effects of surface roughness and asperity contact. The static distortion of cylinder bore, gas pressure variation, and lubricant starvation are also considered in the simulation. Results show that the contact pattern and film thickness between piston ring and cylinder bore are not exactly axisymmetrical. The main reason for the nonuniform contact is the asymmetry of ring elasticity, the static distortion and dynamic load created by the secondary movement of piston skirt.

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