Resilient Split Forging Wheels Railway Tyres For Tram And Metro Light Rail

Resilient Wheels Split Forging Wheels For Tram And Metro Light Rail

The elastic wheel is a kind of split wheel used on rail rolling stock. The elastic elements of elastic wheels are mostly rubber parts. According to the main stress conditions of the rubber elements, the structural forms of elastic wheels can be divided into three types: compression type, shear type and compression-shear composite type. The tire is elastically supported on the wheel, thereby effectively reducing curve noise, reducing track impact, reducing wheel and rail wear and improving the service life of line vehicles.
With the development of urban light rail transit, the noise generated by light rail vehicles running on urban ground or viaducts has become a prominent problem in light rail transit. To solve this problem, elastic wheels are widely used in light rail vehicles all over the world. An elastic unit is installed between the wheel center and the rim of the elastic wheel, and the rim is elastically supported on the wheel, thereby effectively reducing curve noise, reducing track impact, reducing wheel and rail wear and improving the service life of line vehicles. The use of elastic wheels as an effective measure to reduce curve noise has been widely used in low-floor trams, intercity trains, and subway vehicles. The leaders in the research and application of elastic wheels are Europe, Japan and the United States
The elastic wheel is a kind of split wheel applied to the rail rolling stock. According to the state of the wheel rubber element under load, it can be divided into shear type, compression type and shear compression type. The early elastic wheels were mainly made of compression-type rubber pads, and the radial direction of the wheel was elastic and rigid. Its components include rigid tires, rigid wheel centers, and rubber bodies. The rubber body is embedded between the rim and the wheel center.
Compressed
The initial elastic wheel steel parts and rubber components are relatively simple, the rubber components only bear compressive stress, and their axial elasticity is much larger than radial elasticity. The elastic wheel has a simple structure and low mass, and is suitable for small radius wheels. When running and braking, the vertical deformation is small, and the deformation heat is not large, and the tire can be replaced without heating. Pure compression elastic wheels are rarely used now. The Bochum elastic wheels widely used in European light rail transportation are improved compression elastic wheels. The lateral stiffness and radial stiffness of the compression elastic wheel are poorly matched. The improvement of the structure and performance of this wheel mainly focuses on the use of high-performance polymer elastic materials and the use of elastic units with optimized cross-sectional shapes. The elastic wheel shown in Figure 1(c) uses a new polyurethane material, which enters the oval cavity formed by the tire and the wheel center through the injection hole; the elastic wheel shown in Figure 1(d) uses a special The structural form of PTFE is used to overcome the shortcomings of the mismatch between the axial stiffness and radial stiffness of the elastic wheel, and the poor heat dissipation performance of the elastic unit when it is heated.
shear type
Under the action of vertical load and impact load, the rubber element of shear elastic wheel mainly bears radial and tangential shearing action, and the axial compression load produces compression deformation, and the axial elasticity is small. Shear-type rubber elastic wheels can obtain large radial elasticity and small axial elasticity. Therefore, shear-type elastic wheels were widely used in the 1970s and 1980s. However, this kind of elastic wheel has complicated structure, high cost, large mass, large running damping, and inconvenient installation and disassembly.
Compression and shear compound
The compression-shear composite elastic wheel [Fig. 3(a)] adopts a structure that can bear both shear and compression. The rubber elements are usually arranged in a V-shaped arrangement, which can not only make extensive use of the space on the side of the wheel, but also the reasonable distribution of compressive stress and shear stress can be changed with the inclination of the rubber ring, that is, the axial stiffness and radial stiffness can reach the desired optimum. match. This type of elastic wheel has a simple structure, is convenient for installation and maintenance, saves maintenance time and costs, and is widely used. It represents the development direction of elastic wheels. However, this kind of structural elastic wheel has the phenomenon of loose bolts during use, and many patents published in recent years propose improvements to it. The improvement proposed by the German patent [Fig. 3(b)] is to cancel the bolt connection and use a locking ring with a circular section between the pressure ring and the wheel center to locate the V-shaped unit and the wheel rim
Although the elastic wheel has the advantages of reducing curve noise and improving the impact force of the wheel and rail, compared with the rigid wheel, the elastic wheel has a complex structure, high cost and poor operation safety; especially with many bolts, there is a connection between the tire and the elastic pad. In addition, the elastic wheel has strict requirements on the axle load, and the larger axle load is limited by the rubber strength and other conditions, thus limiting its application And development. This is the main reason why elastic wheels are difficult to popularize generally.
In recent decades abroad, in order to achieve noise reduction effect, light rail and subway vehicles have used elastic wheels and muffled wheels with simple structure, convenient installation and maintenance as much as possible under the premise of ensuring safe and reliable operation.
At present, there is no design specification for light rail vehicles and subway vehicles in China. Many domestic vehicle manufacturers temporarily consider the following parameters: the axle load is not greater than 16t, the speed is not greater than 100km/h, and the wheel diameter is 860~915mm. Based on this, five principles for wheel selection of light rail and subway are determined:
(1) The structure is simple and reliable;
(2) It has good operational safety and reliability;
(3) It has good vibration and noise reduction function, and the elastic wheel should reduce the noise by 3~5dB(A) compared with the same kind of steel wheel;
(4) Lower manufacturing costs and maintenance costs;
(5) Good craftsmanship, easy to popularize and apply.
The application prospect of elastic wheels, sound-absorbing wheels and acoustically optimized wheels that can be used for light rail vehicles is preliminarily discussed, and it is considered that elastic wheels may not be used for lines with low noise reduction requirements; it is recommended to give priority to the development of acoustically optimized wheels in China; Elastic wheels and sound-absorbing wheels should be explored on the basis of experimental research to explore the feasibility of popularization and application in my country.