Wuhan, China
Wuhan, China

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Xiang S.-L.,CSR Yangtze Co. | Yan Z.-M.,CSR Yangtze Co. | Liu T.,CSR Yangtze Co. | Zhu W.-M.,Liling Precision Cast Steel Factory
Zhuzao/Foundry | Year: 2013

After cutting the position of transfixion crack in the spherical arc of ZK3 bogie bottom centre-plate, large size shrinkage was found. In order to solve the casting defects of bottom centre-plate, the process measures were adopted such as improving pouring system, increasing chill and pad, etc. The results show that the casting defects such as shrinkage, dispersed shrinkage, slag inclusion, gas hole, etc. were prevented effectively and the castings meet the technical requirement.


Xu Z.L.,Wuhan Textile University | Wang J.,CSR Yangtze Co. | Yang S.S.,CSR Yangtze Co. | He Q.L.,CSR Yangtze Co. | Xiong H.Sh.,CSR Yangtze Co.
IOP Conference Series: Materials Science and Engineering | Year: 2015

A kind of coating suitable for green sand steel casting was developed. Thepractical application showed that the strength of the coating was high enough with no crack and no peeling under room temperature after drying the spraying coating, the performance of the coating for anti-cracking was good under high temperature, and the gas evolution of the coating was low. Using the coating, the casting surfaces finish appearedvery good.


Liu W.-W.,Southwest Jiaotong University | Liu W.-W.,CSR YANGTZE Co. | Jiang R.-J.,CSR YANGTZE Co. | Dai H.-Y.,Southwest Jiaotong University | Zeng J.,Southwest Jiaotong University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2015

The stochastic dynamic model of elastically constrained wheelset system was established subject to track excitation and its structural random parameters. The conditions of the occurence of the first passage failure of the system were obtained in the wake of the analysis of the stochastic global stability of the system with the singular boundary theory. Meanwhile, the backward Kolmogorov equation and generalized Pontryagin equation satisfied by the system reliability function and probability density function of the first-passage time were established, in combination with the initial conditions and boundary conditions to present the problem of the first passage. The results showed that the system energy decreased faster when approaching the boundary of safety work field. The energy initial value, when staying away from the boundary of the safety work field, reduced the peak value of damage probability density and delayed the corresponding time instant. The system was in greatest danger after losing stability in a time instant, rather than what we used to think that the longer the time was, the more dangerous condition the system was in. With the increase of the intensity of the track random excitation, the reliability of the system was reduced faster and the mean first passage time was earlier. ©, 2015, Science Press. All right reserved.


Sun S.-L.,China Academy of Engineering Physics | Sun S.-L.,Southwest Jiaotong University | Li F.,Southwest Jiaotong University | Huang Y.-H.,Southwest Jiaotong University | And 3 more authors.
Tiedao Xuebao/Journal of the China Railway Society | Year: 2015

Piecewise linear model for friction draft gear was built based on the friction draft gear impact test data. The piecewise linear modification model was built after theoretical modification was made with the additional viscous friction force and the additional damping force. The vehicle impact simulation and vehicle relative displacement excitation described by trigonometric function which reflected train operation conditions were used to verify and analyze the piecewise linear modification model. The results indicated as follows: The simulation of modified piecewise linear model was closer to the results of the impact test than the conventional piecewise linear model. Transition velocity from kinetic to static friction and the external displacement excitation frequency had an effect on the nonlinear peak of coupler force. Higher transition velocity or lower external frequency caused the coupler force to switch to the nonlinear peak more quickly, and to produce larger hysteresis loop, more vibration energy and smaller subsequent coupler force and relative displacement. The additional viscous friction force simulated the nonlinear peak of the characteristic curve of the draft gear well. The larger equivalent friction coefficient led to a larger additional viscous friction force and coupler force. The combined effects of the additional damping and vehicle structure stiffness resulted in smooth transition between loading curve and unloading curve of the draft gear. Under the modification of additional damping, the draft gear formed a hysteresis loop even if the draft gear suffered loading and unloading on the intermediate curve, and dissipated the vibration energy between the vehicles. ©, 2015, Science Press. All right reserved.


Huang J.,China University of Technology | Yan Z.-M.,CSR Yangtze Co. | Zhang Y.-S.,China University of Technology | Long W.,China University of Technology | And 2 more authors.
Zhuzao/Foundry | Year: 2014

By analysis on mechanisms of low strength of green sand mold and peeling and crack of coating that is sprayed on the green mold, an alcohol base corundum compound spray coating is developed to apply to the green sand mold for steel castings. This coating has excellent suspension stability under low density of 50 Baume degree. The coating is not peeled off or does not appear crack when it is sprayed thickly on the green sand mold. The coat has high heat stability and does not react with metallic oxides such as FeO to produce low melt phase when it touches molten steel. This coating has strong ability to resist penetration of molten steel. Bolster and side frame steel castings with clean surfaces can be produced by this coating.


Patent
Csr Yangtze Co. | Date: 2012-10-25

A wheel truck, including: a front wheel pair assembly and a rear wheel pair assembly, two side frame assemblies, two spring suspension devices, and a bolster assembly. The spring suspension devices include a bearing spring unit, a damping spring, and a wedge. The wedge includes a primary friction surface and a secondary friction surface. The primary friction surface is attached to a column surface of the side frame assembly. The secondary friction surface is attached to an inclined surface of the bolster assembly. The wedge has the following structure parameters: =16-30, and


Patent
Csr Yangtze Co. | Date: 2012-10-30

A lower side bearing for a wheel truck, including: a first friction board, a second friction board, an inner pedestal, a bearing sleeve sleeving the inner pedestal, a pressure block, a pressure plate, and an elastic component. The pressure block is disposed on an upper part of the inner pedestal, and the second friction board is disposed on a top of the pressure block. The pressure plate is disposed on an upper part of the bearing sleeve, and the first friction board is disposed on a top of the pressure plate. A friction coefficient _(k )of the first friction board and a friction coefficient _(z )of the second friction board meet the relation: _(k)>_(z). The elastic component is disposed between the inner pedestal and the bearing sleeve for controlling a relative position of the inner pedestal and the bearing sleeve.


Patent
Csr Yangtze Co. | Date: 2012-10-30

A wheel truck for a railroad car, including: a front wheel pair assembly and a rear wheel pair assembly; two side frame assemblies, each side frame assembly including a square box and journal-box guides; two spring suspension devices; and a bolster assembly including two ends disposed on the two spring suspension devices, respectively. The bolster assembly includes a pilot hole in the center and two mounting holes on the two ends, the pilot hole is rotationally matched with a cylindrical upper center plate of a car body for transmitting vertical and horizontal forces from the car body, and the two mounting holes are disposed above the two spring suspension devices, respectively. Each mounting hole receives a lower side bearing, and the lower side bearing is matched with a corresponding upper side bearing disposed on each side of the car body for transmitting the vertical load from the car body.


Patent
Csr Yangtze Co. | Date: 2012-10-25

A damping device, including: a wedge assembly having a wedge including a vertical surface and an inclined surface; a primary friction board disposed on the vertical surface; and a secondary friction board disposed on the inclined surface; and a damping spring assembly disposed underneath the wedge assembly. The wedge assembly has the following structure parameters: =16-30, and

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