Experimental Studies Using Response Surface Methodology for Condition Monitoring of Ball Bearings

Abstract

The presence of defect in the bearing (outer race, inner race, or ball) results in increased vibrations. Time domain indices such as rms, crest factor, and kurtosis are some of the important parameters used to monitor the condition of the bearing. Radial load and operating speed also have an important role in bearing vibrations. The interaction between the defect size, load, and speed helps to study their effect on vibrations more effectively. Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and the outputs of a physical system. But so far, the literature related to its application in bearing damage identification is scarce. The proposed study uses RSM to study the influence of defect size, load, and speed on the bearing vibrations. Kurtosis is used as response factor. Experiments are planned using Box Behnken design procedure. Experiments are performed using 6305 ball bearings and the results have been presented. MINITAB statistical software is used for analysis. It is seen from the analysis of the experimental results that the defect size, interaction effect of defect size and load, and interaction effect of defect size and speed are significant. Response surface method using Box Behnken design and analysis of variance has proved to be a successful technique to assess the significant factors related to bearing vibrations.

Theoretical and Experimental Studies on Vibrations Produced by Defects in Double Row Ball Bearing Using Response Surface Method

“…But for speed and defect size contour plot ( Figure 6 and Figure 7) it will give much of area under the graph. These indicate exactly same effect given by experimental result [3,9].…”

“…Also it shows linear variation in the first graph. These same effects are seen in the surface plot graph of load and defect size as well as speed and defect size [3,9] which gives exactly same effect given by experimental result. …”

“…The design is obtained by the combination of 22 designs with a balanced incomplete block design having three treatments and three blocks. The advantages of these designs include the fact that they are all spherical designs and require factors to be run at only three levels and there are no runs where all factors are at either the+1 (highest value) or −1 (lowest value) levels [3].The design matrix designed for experimentation with the help of MINITAB software with Box-Behnken designs and considering three factors. The factors are Defect size (Circular in mm), Load (in N) and Speed (in rpm).…”

“…Patil M.S. et al [3] studied that the presence of defect in the bearing results in increased vibrations. Time domain indices such as rms, crest factor, and kurtosis were some of the important parameters used to monitor the condition of the bearing with RSM he has developed the model with Kurtosis.…”

“…Design of experiments (DOE) helps to understand how the influence factors interact with the system. Methods such as factorial design, Response Surface Method (RSM) [3].…”