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Fault diagnosis of bearings is essential in manufacturing to increase quality. Traditionally, fault diagnosis of tapered roller element bearings is performed by signal processing methods, which handle the nonstationary behaviour of the signal. The wavelet transform is an efficient tool for analysing the vibration signal of the bearings because it can detect the sudden changes and transient impulses in the signal caused by faults in the bearing elements. In this article, manufacturing faults on the outer ring of tapered roller bearings due to the grinding process in manufacturing are investigated. Nine different real values wavelets (Symlet-2, Symlet-5, Symlet-8, db02, db06, db10, db14, Meyer, and Morlet) are compared according to the Energy-to-Shannon-Entropy ratio criteria, and which is efficient for detecting the manufacturing faults is determined. Finally, experiments are carried out on a test rig for determining the geometrical size of the manufacturing faults with all wavelets directly from the vibration signature the result of db02, Symlet-5, and Morlet wavelets are presented. When modelling the bearing structure as an under-damped second-order mass-spring-damper mechanical system, its unit impulse response function is compared to the wavelets on the basis of their Energy-to-Shannon-Entropy ratio to determine the fault size from the vibration signal. The proposed technique has been successfully implemented for measuring defect widths. The maximum deviation in result has been found to be 4.12 % for the defect width which was verified with image analysis methods using an optical microscope and contact measurement. Odkrivanje napak v izdelavi je ključnega pomena za izboljšanje kakovosti proizvodnje ležajev. Namen članka je analiza možnosti odkrivanja napak v izdelavi koničnih kotalnih ležajev iz signala vibracij ter ugotavljanje geometrijske velikosti napak na zunanjem obroču. Tradicionalne metode, kot je Fourierjeva transformacija, zaradi posebne narave signalov niso dovolj uspešne pri zaznavanju prehodnih impulzov. Konični kotalni ležaji so le redko predmet znanstvenih člankov, čeprav predstavljajo pomemben del avtomobilskih menjalnikov in sistemov prenosa moči. Večina znanstvenih člankov, ki se ukvarjajo z obrabo, se kljub pomenu te problematike ne posveča težavam pri izdelavi. V članku je zato predstavljena nova rešitev, ki bi jo bilo mogoče učinkovito uporabiti v industriji.

The rubber bumpers built into the air-spring structures of buses perform a number of critical tasks. Consequently, designing their shape requires considerable effort. This paper presents a novel solution for determining the required characteristics of axi-symmetric rubber parts, which can efficiently be used in practice. The procedure is based on the finite element method (FEM) and the support vector regression (SVR) model. A finite element code developed by the authors and based on a three-field functional is used for the rapid and appropriately accurate calculation of the characteristics of rubber bumpers. A rubber shape is evaluated via the work difference and the area between the desired and the actual load-displacement curves. The objective of shape optimization is to find the geometry where the work difference is under a specified limit. The tool of optimization is the SVR method, which provides the regression function for the work difference. The minimization process of the work-difference function leads to the optimum design parameters. The efficiency of the method is verified by numerical examples. Gumijasti blažilniki, vgrajeni v sisteme zračnega vzmetenja avtobusov, opravljajo vrsto pomembnih nalog, konstruiranje gumijastih blažilnikov pa je zato precej zahtevno. V članku je predstavljena nova, praktično uporabna rešitev za zagotavljanje zahtevane karakteristike gumijastih osnosimetričnih blažilnikov. Prava karakteristika podajanja pod obremenitvijo je osnovna zahteva pri snovanju gumijastih blažilnikov. Avtomobilska industrija mehkejšo ali tršo izvedbo gumijastih blažilnikov običajno zagotavlja s spremembo sestave gume. Cilj optimizacije je doseganje zahtevane karakteristike z geometrijsko obliko gumijastega blažilnika ob nespremenjenih lastnostih materiala. Namen raziskave je določanje vedenja gumijastih blažilnikov pri različnih delovnih pogojih. Gumijasti blažilniki se ne upravljajo aktivno, zato je zahtevano karakteristiko mogoče doseči z optimizacijo oblike.