Application of Ultrasonic Nanocrystalline Surface Modification Technology for Prolonging the Service Life of Double Row Angul

Author:  Cho, Amanov, Cho, Pyun
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 231-236)
Doc ID:  2011038
Year of Publication:  2011
Abstract:  
Abstract Double row angular contact ball bearings (DRACBB) - are capable of carrying high radial and thrust loads in both directions and need small space comparing to two single row angular contact bearings. A newly developed magnetic clutch of compressor needs higher dynamic load rating without increasing space for bearings. Therefore, Ultrasonic Nanocrystalline Surface Modification (UNSM) technology is applied to bearing raceways in order to improve rolling contact strength and to reduce friction loss. The rolling contact fatigue and friction test specimens which are treated by UNSM technology are performed in order to find proper surface hardness, topology and compressive residual stress. Comparison test of service life and friction coefficient between UNSM-treated and untreated bearings were carried out in the bearing test rig. After UNSM treatment, the friction coefficient was reduced and the service life was extended at room temperature due to the UNSM treatment. Life tests data showed that the life of the UNSM-treated bearings was much longer than that of the untreated bearings. The basic mechanism and effects of UNSM technology were also explained. Keywords Double row angular contact ball bearing (DRACBB), friction, fatigue, ultrasonic nanocrystalline surface modification (UNSM).