Research For A Low Floor Railway Vehicle Bogie Scheme Wit Small Diameter Wheel

The method of using 100% low-floor railway vehicles is one of the effective solutions to solve urban traffic problems, whose related bogie technology develops rapidly in the domestic and overseas at present. The core technology of achieving the goal of 100% low-floor structure is the design of the bogie. There are two technology routes:one is using independently rotating wheel, the other is traditional small diameter wheel. In the past, the domestic research about 100% low-floor railway vehicle bogie used to stay in the aspect of the inherent characteristics of those two kinds of bogies, and rarely involved the aspect of their structural characteristics. This thesis using Bombardier’s FLXEE URBAN 3000 bogie as prototype, researches the structural characteristics of traditional small diameter wheel bogie. The work of this thesis is as follows:1. Put forward three design schemes of small diameter wheel bogies. Each scheme contains power and non-power bogies with their 2D and 3D models. The schemes design wheelset, frame, axle-box, primary and secondary suspension, drive system, brake disc, brake clamp interface and so on in detail and compare the advantages and disadvantages of three kinds of schemes in the aspect of structure performance. The results show that the third scheme is more superior than the others.2. Study the characteristics of involved bogie suspension in detail. Analyzes are mainly forced on the characteristics, advantages and disadvantages of two kinds of secondary suspension, namely, hourglass rubber spring and large deflection steel spring. The results show that:low-floor railway vehicle bogie primary suspension’s stiffness is larger than secondary suspension’s. Secondary suspension can adopt air spring, hourglass rubber spring and large deflection steel spring. When choosing it, we should consider actual manufacturing level, the bogie spatial structure and combine with the actual weight and empty features of carbody.3. Study positioning structure of tilting primary suspension rotating arm axle-box, which is the first difficulty of the key technology in bogie scheme. Deduce the theoretical formula about positioning stiffness of this axle-box structure and simplify calculation formula for engineering. Validate the correctness of the formula by SIMPACK software, and analyze the axle-box parameters which impact the axle-box positioning stiffnessas well.4. Calculate the stiffness of rotating arm node and primary suspension rubber in theoretical and simulation methods. The results show simplifying rubber material as linear constitutive relations can reflect the stiffness of rubber component approximately in FE method.5. Study the longitudinal arrangement drive system in detail, which is the second difficulty of the key technology. Research in aspects of the suspension of traction motor and driving gear box, the choice of coupling, the influence of the suspension parameters to the coupling deeply. Design the driving gear and check its bending fatigue strength and contact fatigue strength. Select gear box axial bearing and pinion shaft axial bearings.6. Propose detailed dynamic characteristic parameters of the third scheme.