Development of a longitudinal-torsional ultrasonic assisted roller dressing device for precision form grinding of GCr15 bearing rings

Abstract

Abstract High-quality and highly precision dressing is essential to achieving precision form grinding of GCr15 bearing rings. A method of longitudinal-torsional ultrasonic assisted roller dressing (LTUARD) was proposed for achieving high precision and high-quality dressing. A device of LTUARD was developed for investigating the dressing effect of the longitudinal-torsional ultrasonic assisted roller on the white alumina (WA) grinding wheel. The longitudinal-torsional horn with roller loading was mainly studied during the device development of LTUARD. The geometric dimensions of the longitudinal vibration horn with large tool head were firstly determined by the set of transcendental equations, and then the longitudinal vibration was converted to longitudinal torsional vibration by adding a helical slot in the conical section. Subsequently, the results of the impedance analysis and vibration characteristics experiments of the longitudinal-torsional ultrasonic vibration system show that the vibration system meets the vibration requirements of LTUARD. The vitrified bonded white alumina (WA) grinding wheel dressing experiments were carried out using conventional roller dressing (CRD) and LTUARD respectively, and the grinding of GCr15 bearing rings with the before dressing (BD) and after dressing of WA grinding wheel. The results of dressing and grinding experiments show that the surface morphology and roundness error of WA grinding wheel are improved after LTUARD, and the surface quality of GCr15 bearing rings ground by WA grinding wheel after LTUARD dressing is better. The reliability and practicality of the developed dressing device were verified by the dressing and grinding experiment results.