Study on the Life Distribution and Reliability of Roller Based Linear Bearing

2007 ◽  
Author(s):  
Shigeo Shimizu ◽  
Hirokazu Shimoda ◽  
Katsuji Tosha
Keyword(s):  
Fatigue Life ◽  
Test Data ◽  
Dynamic Load ◽  
Distribution Functions ◽  
Load Rating ◽  
Life Test ◽  
Life Distribution ◽  
Dynamic Load Rating ◽  
Log Normal ◽  
Log Normal Distribution

A study on the life distribution and reliability for roller guides with cage is carried out with a total number of 90 test samples in two lots (Ns = 38 and 52), and fatigue life distribution functions, such as two and three parameters Weibull distribution, and log-normal distribution are used for analyzing the test data. The basic dynamic load rating formula standardized by ISO in 2004 is also compared with the life test data in relation to the effect of crowning on both ends of the carriage raceway. Weibull slope, compatibility of distribution functions and λbm factor are also examined.

Rolling Fatigue Life and Reliability of Ball Screws

2007 ◽  
Author(s):  
Hirokazu Shimoda ◽  
Shigeo Shimizu ◽  
Katsuji Tosha ◽  
Yushi Otani
Keyword(s):  
Fatigue Life ◽  
Weibull Distribution ◽  
Test Data ◽  
Dynamic Load ◽  
Ball Screw ◽  
Test Machine ◽  
Load Rating ◽  
Life Test ◽  
Dynamic Load Rating ◽  
Fatigue Life Test

The experimental formula based on Lundberg-Palmgren theory has been used for the calculation of basic dynamic load rating of ball screws because its contact state resembles that of angular contact ball bearings. However, the compatibility between the theoretical and the actual rating life of ball screws has not been yet confirmed by life tests and probability theory. The inherent properties of ball screws are also not considered in this formula. In this paper, the authors deal with the development of ball screw life test machine and fatigue life test for ball screws with a total number of 31 test samples. Type and occurrence location of the initial failure of each sample are investigated. The fatigue life test data are analyzed with two and three parameters Weibull distribution functions. The basic dynamic load rating of the ball screws are also estimated from the life test data. The results are summarized as follows: (1) Initial failures are generated at the surface of the balls and the nut raceway as a spalling. (2) The life distribution of the test data fairy well fits three parameters Weibull distribution function. (3) Basic dynamic load rating, which is estimated by the life test, is approximately in agreement with that of manufacturer’s catalog.

Study on the life distribution of microdrills

2002 ◽  
Vol 216 (3) ◽  
pp. 301-305 ◽  
Author(s):  
Z Yang ◽  
Y Chen ◽  
Y Yang
Keyword(s):  
Distribution Function ◽  
Normal Distribution ◽  
Reliability Function ◽  
Test Methods ◽  
Life Distribution ◽  
Machining Processes ◽  
Experimental Conditions ◽  
Distribution Parameters ◽  
Log Normal ◽  
Log Normal Distribution

In this paper, the life distribution of microdrills has been studied experimentally. The fit and test methods of the life distribution function of microdrills are described. Under the experimental conditions of the present work, it is concluded that the life of microdrills follows the log-normal distribution and the distribution parameters are different for various workpiece materials. The life distribution function and reliability function of microdrills from the present work provide a base for correct changing of drills in automatic machining processes.

A SIMPLIFIED WAY OF ESTIMATING A DYNAMIC LOAD RATING FOR THRUST ROLLER BEARINGS

Tribologia ◽  
2020 ◽  
Vol 289 (1) ◽  
pp. 49-55
Author(s):  
Michał LIBERA
Keyword(s):  
Dynamic Load ◽  
Linear Interpolation ◽  
Load Rating ◽  
Rolling Bearings ◽  
Thrust Bearings ◽  
Bearing Angle ◽  
Speed Up ◽  
The Difference ◽  
Dynamic Load Rating ◽  
Selection Of

The method of calculating the bearing capacity of rolling bearings is described in the ISO 281 standard. The calculation procedure for roller thrust bearings presented there, depending on the value of the nominal bearing angle, requires the selection of one of two formulas. Then, using the table, one reads the value of the factor depending on the geometry of the bearing components. To facilitate and speed up calculations (and perhaps also increase their accuracy), this article proposes a formula that is adapted to numerical applications, replaces linear interpolation with a proper non-linear function and allows calculations to be made for a specific value of the nominal bearing angle, but not within the range of 15°. The difference between the values calculated according to the proposed formula and the value calculated according to ISO 281 is, on average, around 3%.

Re-Evaluation of Basic Dynamic Load Rating and Life Formula for a Ball Screw

2007 ◽  
Vol 50 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Shigeo Shimizu ◽  
Hirokazu Shimoda ◽  
Chandra Shekhar Sharma
Keyword(s):  
Dynamic Load ◽  
Ball Screw ◽  
Load Rating ◽  
Dynamic Load Rating

Statistical and Probabilistic Analysis of Thermal-Fatigue Test Data Generated Using V-Shape Specimen Testing Method

2013 ◽  
Author(s):  
Zhigang Wei ◽  
Burt Lin ◽  
Kay Ellinghaus ◽  
Markus Pieszkalla ◽  
D. Gary Harlow ◽  
...  
Keyword(s):  
Test Data ◽  
Thermal Fatigue ◽  
New Product ◽  
Distribution Functions ◽  
Life Test ◽  
Thermal Fatigue Test ◽  
Probability Distribution Functions ◽  
Testing Method ◽  
Specimen Test ◽  
Rank And Select

V-shape specimen testing is a relatively new, simple and useful technique to characterize the thermal-fatigue resistance of materials subjected to combined thermal/mechanical loadings, and to rank and select materials. However, the V-shape specimen test data, similar to many other life test data, always contain an inherent scatter not only because of material non-uniformity but also of the difficulties in operating control, such as loading, boundary conditions, and environment. Therefore, statistical and probabilistic approaches have to be used to interpret the test data in order to implement the observations into new product designs. In this paper, the V-shape specimen test data are selected, analyzed and the scatter properties of the test data are fitted using several continuous probability distribution functions. The results are compared, and the root failure mechanisms of the V-specimens are also discussed. Finally, the main observations are summarized, and a recommendation is provided.

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