The Research Of Structure And Rolling Technology Of The Railway Wheel

With society developing, there are more and more stock and people to be transported, which aggravated the burden of the carrying trade. As a kind of important conveyance, it needs rail train (including engine, over loading train, high speed train, city rail train and so on) to grow high speed and over loading. However, the higher speed and the heavier axle make the load on the wheel, which is the most important part of the rail train, become more complex. There are varieties of failure forms threatening the life of the rail wheel all the time, such as abrasion of the wheel, abrading of the tread, fatigue crack, etc.According to the structure of the wheel, it consists of the wheel with hoop and the integrative wheel. As the rail train developing, the integrative wheel has gradually replaced the wheel with hoop, and comprehensive used. The forces on the wheel have been analyzed the time that it is under the dead load, or that it is normal running, or that it is braking, though ANSYS a kind of finite element analysis soft. So there are three conclusions here. First, when it is under dead load, the greatest stress of the wheel occurred inside the hub. The value is in the safe range. And the wheel is not seriously damaged; Secondly, when the wheel is normal running, the greatest stress appeared on the knuckle between wheel web and the hub. The value is greater, so it has a relative great effect on the wheel. Third, when it is braking, the abrasion of the tread is remarkable. Undoubtedly it is an illumination for improving the structure of the wheel.In order to insure the inner quality, the shape, dimension and the precision, it is essential to make a reasonable deforming craft. Rolling is an important part of the thermal deforming, with responsibility for extending the diameter and the web. As well as, the precise deformation of the rim, the edge and the tread is finished by rolling. Because the shape of the wheel is complex, there are many rollers in the rolling process. Otherwise, there are varieties of controls parameters and the rolling cylinder number of the wheel is a lot. The wheel rolling is a special form of loop rolling, however it is more complex than the ordinary loop rolling.Actually, such a complex rolling process must depend on an appropriate rolling mill. According to the position of the wheel, rolling mills include horizontal rail wheel rolling mills and vertical rail wheel rolling mills. Compared to horizontal rolling mills, vertical rolling mills have more advantages, including: (1) The wheel web can be reduced uniformly, and it can avoid to producing steps; (2) It is benefit to reduce the eccentricity of the wheel; (3) Because the wheel is always in the vertical position during the rolling process, it prevents the surface of the wheel form being damaged by the oxide skin. And the tailor-made edger rollers on the vertical rolling mill are used to confirm the width of the rims, which can reduce the glide of the wheel and it is easily deformed; (4) The rollers on the vertical rolling mill are independent, each roller has its solely movement. So the rollers are universal, as well as, it costs less; (5) Large draught pressure, it has less rolling time and better rolling quality than the horizontal rolling mill as a super large wheel is rolled; (6) The edger rollers and the web rollers on the vertical rolling mill individually in the charge of deforming the rim and the web of the wheel. So it can roll the web with different thickness; (7) When a hot stock is rolled, its dimension is measured by the laser. And the precision can reach the level of millimeter.However, it is hard to control the three-dimensional position of the rollers on vertical rolling mill. And it is discommodious for the delivery of the stock on vertical rolling mill. On horizontal rolling mill the stock and the wheel can be delivered at the same time to reduce the assistant time. Different from horizontal rolling mill, on vertical rolling mill the stock can not get in until the wheel gets out. In allusion to these problems, a new rail wheel vertical rolling mill appeared in the thesis, and it brought forward the design proposal of general mechanism. Furthermore it confirmed the final running scheme and the structure scheme of complete appliance after analyzing the main problems in the scheme.There are main gearing, frame, roll bearing, side pressure gearing, rail chair, roll regulation equipment, roll change mechanism, etc. on new rail wheel vertical rolling mill. Primary components on the rolling introduced weldable steel with low stress, and all gear shafts, accessories and rollers are fixed on the bearing block. The design of rollers and conveyer equipment is the keystone in the thesis.First of all, some primary parameters of the rollers are confirmed, such as the diameter, rolling pressure, rolling speed and so on. The new vertical rolling mill is comprised with eight rollers, including one king roller, two web rollers, two edger rollers, two centring rollers and one guiding roller. The web rollers are active, which take charge of rolling the inner surface of the rim and the web. The king roller takes charge of rolling the flange and the tread of the wheel. The edger roller takes charge of rolling the lateral surface of the rim, and making the width of the rim under control. And the centring rollers and the guiding roller can balance the pressure with responsibility for guiding and locating. Additionally, the new vertical rolling mill has an orbital conveying mechanism. Compared with conventional conveying mechanism, the worked efficiency is increased. When it is feeding, the stock rolls directly into the pass formed by the guiding roller and two centring rollers. And when the rolling process is finished, the guide will shift to the right, at the same time, the left centring roller will get down and the right centring roller will shift up. Once they are in the appropriate position, the formed wheel will slide to the next process.As the deformed tools, the rollers contact with the wheel directly. How to design the shape and the dimension is relation to the situation of the formed wheel. So it is significant to design the rollers exactly. Firstly, the shape and the dimension of a rough wheel and a stock should be finished. During this time, the precise allowance for finish are confirmed which relates to the parameters of the vertical rolling mill. According to hardness condition, working circumstance and previous experience, the design of all the rollers on the new rail wheel vertical rolling mill is completed in the thesis.