The structural design of the new air spring requires a strong bearing capacity and a small profile due to the new air spring. Considering the installation height and the stability of the existing flat rubber pile, the belt-type capsule is combined with the flat rubber pile in the product development. Structure. The air-to-air load of the air spring is 50kN and 180kN respectively. The difference is relatively large. According to the condition that the load can be assumed to be 180kN when the predetermined internal pressure is 055MPa058MPa, the effective diameter of the new air spring should be between 630mm and 650mm. According to the new air spring The vertical maximum displacement is 30mm. In combination with the aforementioned stability factors, the lateral maximum displacement of the new air spring is 60mm, which is much smaller than the maximum displacement of the air spring without the bolster bogie. It is relatively easy. Since the maximum outer diameter of the new air spring capsule is not more than 740mm, in order to ensure the stability of the effective diameter of the air spring capsule, the design experience of similar air springs in foreign countries is adopted. The capsule finally adopts a belt structure, that is, the waist ring is added in the middle of the capsule. Limit excessive expansion of the capsule. The structure of the SYS640G air spring exported to India is covered with a cover, and the upper end is provided with an anti-drop structure, which can ensure the reliability of the air spring seal when the displacement is large; the lower end of the capsule is closely attached to the support seat, and the support seat It also has an anti-shedding structure. The flexural deformation portion of the capsule is fitted by arcs and tangent lines of different radii. Taking into account the lateral stiffness and height requirements of the air spring, the rubber pile is provided with three layers of rubber, separated by two layers of metal plate rings, and the three layers of rubber have a certain degree of curvature, and the arc is substantially flattened in the vertical compression state, which reduces the work. The tensile stress of the surface when the rubber is compressed. The inner hole of the rubber has a certain taper to facilitate the mold release during production. The pile acts as an emergency spring when the air spring is running without air. According to the characteristic parameters of the air spring, it is named SYS640G air spring and is included in the SYS air spring series. Theoretical Analysis The new air spring system consists of a belt rubber bag and a flat rubber pile in series. In the early stage of development, air spring capsules and rubber piles were calculated by finite element method. As a key component of the air spring, the capsule determines the vertical and lateral characteristics of the entire air spring. In order to reduce the deformation stress of the air spring, the initial shape of the capsule is designed to be similar to the shape when it is in operation, and the arc length of the deformable portion of the capsule determines the lateral deformation ability of the air spring. The waistband structure on the capsule can effectively restrain the expansion of the outer diameter of the capsule in the inflated state and reduce the tensile stress of the surface rubber. The finite element discrete model of the capsule, as shown, has 2980 units and 4140 nodes. The stress distribution cloud diagram of the capsule at internal pressure of 05MPa is given, and the characteristic curves of the internal pressure of the air spring, the vertical stiffness of the internal pressure and the lateral stiffness of the internal pressure are given respectively. The calculation results of the relevant parameters are listed in . It can be seen that the performance of the capsule meets the technical requirements. Air spring internal pressure lateral stiffness curve Air spring calculation result Internal pressure / MPa vertical load / kN vertical stiffness / (Nmm - 1) Lateral stiffness / (Nmm - 1) 0.150506302700.51016512504900.55818014105204.2 Rubber pile flat rubber pile The structure is relatively mature, and most of the air springs use this structure. Compared with the cone rubber pile, the flat rubber pile has a large vertical stiffness and a small lateral stiffness. When the air spring generates a lateral displacement, the flat rubber pile can bear a partial lateral offset, thereby reducing the deformation of the capsule. The amount and stress on the rubber surface. The finite element discrete model of the rubber pile is shown as a total of 7704 units and 8750 nodes. The stress distribution cloud diagram of the rubber pile is given when the vertical load is 180kN and the lateral offset is 20mm. The vertical load displacement and lateral load displacement curves of the rubber pile are given respectively. Vertical load and internal pressure relationship Under static conditions, the vertical load and maximum outer diameter of the air spring at different heights (H) and different internal pressures were measured. The vertical load and geometric parameters of the air spring at the standard working height (H=255mm) are listed. 1 is the load internal pressure curve at different heights. It can be seen that the vertical load increases with the increase of internal pressure and has a linear relationship, while the effective diameter and the maximum outer shape of the air spring remain basically unchanged. When the air spring is stretched and compressed by 10 mm from the standard working height, the load carrying capacity does not change much. These are important features of belt air springs and are the main difference from other structural air springs. Vertical characteristics In order to study the vertical characteristics of the air spring, at the standard working height, the additional air chamber volume of the air spring is set to 20L, 30L and 40L, respectively, and the vibration speed is 5mm/s, respectively, under different vertical loads. The vertical amplitudes of 10 mm, 20 mm, and 30 mm were vibrated, and the resulting air spring vertical stiffness was measured. It can be seen that the vertical test stiffness of the air spring is smaller than the theoretical calculation value, but it meets the technical requirements. The vertical stiffness of the air spring increases as the vertical load of the air spring increases, decreases as the volume of the additional air chamber increases, and decreases as the amplitude increases. Therefore, under the condition that the vibration condition is constant, the vertical characteristic parameter of the air spring can be adjusted by changing the working pressure of the air spring and the volume of the additional air chamber. Polyurethane Products，PU Products，Products for Polyurethane Middle Duty Caster Co., Ltd. , http://www.nbcasters.com