PSI - Issue 59

Andrii Senyk et al. / Procedia Structural Integrity 59 (2024) 508–515 Andrii Senyk et al. / Structural Integrity Procedia 00 (2023) 000 – 000

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bushing, as well as new methodology for measuring and evaluating this parameter using harmonic analysis and small sample theory, which would ensure improved quality indicators of the assembly unit, which includes kingpin rolling bushing, is an important task. New technology for the manufacturing of rolling kingpin bushings and their assembly into assembly units with increased accuracy of their ICS shape and angular orientation. To create new methodology for determining the macrogeometry of the bushings ICS shape. Using harmonic analysis and the theory of small sampling, to determine the areas with maximum deviations from roundness on the averaged circlegrams of the bushings ICS. To improve the technology of these bushings calibration by means of elastic fillers developed by the author. To improve the operation of these bushings conjugation with the journal holes by implementing angular orientation and ensuring the contact area of the bushings ICS with minimal deviations from roundness with the kingpin cylindrical surfaces. 2. Results and discussions The essence of the proposed technological solution consists of two stages. At the first stage, the research work is carried out. It establishes the regularity of deviations from roundness by the rotation angle, the stability of the technological process during the operation of rolling the card into the bushing and determines the areas with the maximum deviation from roundness Δ max in the sectors bounded by the central angle  90  . At the second stage, improved technological operations for calibrating rolling kingpin bushings in elastic split fillers and assembling these bushings with journal and simultaneously ensuring the angular orientation of the area with minimal deviations from the roundness of the bushing in the contact area of the bushing ICS with the outer cylindrical surfaces of the kingpins, as well as bushing IICS boring are presented. The essence of the first stage is as follows. According to the traditional technology, the first technological operation is performed - bushing rolling and pilot batch of 15 such bushings is manufactured. Due to the presence of springing card during rolling, the bushings ICSs have significant deviations from roundness and it is not possible to use existing devices to measure them. In this case, the ends of the rolling bushings are ground and then scanned. The resulting end face prints are enlarged to the specified scale and the traces of the bushing ICSs are obtained in the form of distorted circles, i.e., circlegrams. In each of these circles, the adjacent, at least at the three points of the profile most distant from each other, points of the profile are entered, the circle is divided into і ( і = 1, 2, 3...24, 36) evenly distributed positions and the distances from the points of the real profile of the bushing ICS to the adjacent circle are determined in each of them and, as a result, the values of deviations from roundness i  are obtained. In the given example of the specific implementation of the proposed technology, the circlegrams shown in Fig. 2 are divided into 24 positions, and the data on deviations from roundness i  in each і -th position for each j -th ( j =1,2,3...10) bushing are given in Table 1. The obtained statistical data were processed. For each j -th bushing in each of the i -th positions, the deviation from roundness ji  was presented as a random variable. To determine the mathematical expectation ( ) ji M  and dispersion ( ) ji D  from (Kryvyi et al. (2013), we used the dependencies obtained by the method of small-sample theory for 10  n .