MATH SIMULATION AND OPTIMIZATION OF INNER DESIGN OF TAPERED CARTRIDGE BEARING UNITS FOR 1520 RAIL SPACE

Abstract

Development of high-speed passenger transportation is closely related to the application of closed tapered cassette bearing units. Due to the fact that the above mentioned closed cassette bearing units do not have grease replacement, wear products remain inside the bearing during the whole operation period and later through increasing of their amount they start to work as an abrasive causing almost exponential intensified wear. To get high operational parameters (8 years of service life or 800 thousand kilometers of maintenance-free run) during designing of closed bearing units it is required to provide limited decrease of wear. Main features of mathematical simulation and optimization of inner geometry of tapered cassette bearings are considered in the paper. The goal of this research was development of specified mathematical models to define features of loading and stress-strain behavior as well as further optimization of inner geometry of double row tapered cassette bearings for 1520 gauge railways. Finite element method was taken as the main method of research. At the first stage mathematical model included adapter, double row outer ring, tapered rollers, two inner rings, wheel set axle, wheel and rail that were in mutual non-linear contact interaction. The bearing unit itself was explored at the second stage – closed tapered “cassette” to define distribution of loading in circumferential direction. In the result of performed work it was investigated several typical sizes of tapered cassette of double row cassette bearings – 130x230 mm, 150x250 mm and 130x250 mm. The authors developed complex multi-contact finite element model to analyze stress-strain behavior, strength and durability of tapered “cassette” for 1520 gauge railways. Main patterns of stress-strain behavior and optimum inner geometry of tapered cassette were developed.