principle of operation
Air cushion shoes originally used Air Sole cushioning technology, and Air Sole is the prototype of NikeAir. The invention of this cushioning technology not only improves the shock absorption performance of the shoe midsole, but also reduces the weight of the midsole. More importantly, the appearance of air cushion is not only the gospel of athletes, the cornerstone of Nike empire, but also the symbol of high-performance sports shoes, which has become the goal that sports manufacturers all over the world compete to surpass and stimulated the vigorous development of sports shoes technology.
We know that the lightweight Nike air cushion can give consideration to both shock absorption and protection, and its super adaptability makes it suitable for all kinds of sports shoes. Moreover, the air cushion has been expanding the family, and now it has become Nike's largest technology series.
Sealed compression air cushion. The air cushion is pressed into the midsole of the shoe and cannot be seen from the outsole.
Max—— Special gas is injected into a tough synthetic rubber at high pressure, and the air cushion pressure is 5psi. 10psi.20psi.25psi, forming air chambers with different pressures, which can provide more shock absorption performance. Moreover, sneakers based on Max Air technology usually use less materials based on foam rubber shock absorption in the midsole, so the weight of sneakers can be appropriately reduced. Max Air is usually visible and is generally used in the forefoot and heel of shoes.
Full sole air cushion. It is an upgraded version of Max Air, which consists of several air cushions with different pounds. According to the number of pounds of air cushion required by each part, it provides safer and more comfortable protection and shock absorption for athletes.
Tuned- evolved from Max Air, made of several groups of semi-spheres made of polyurethane materials, which provide extra shock absorption performance for sports shoes in specific areas.
Zoom is an advanced damping system based on Nike Air technology, which can provide quick response and buffering performance closer to the ground. Zoom Air-sole unit consists of two layers of high-density nylon elastic fiber three-dimensional fabric sealed by polyurethane airbag.
This combination makes the air cushion react quickly to disperse the pressure when it is strongly impacted, which is a bit like a trampoline. Zoom Air is often placed in the forefoot of basketball shoes, but it is also used in the heel in a few cases.
Shox-Nike's damping technology is a special cylindrical moving part made of high-density polyurethane foam rubber. In the application of basketball shoes, its special design and structure can provide excellent stability and high-level impact protection.
Extended data
Air cushion in navigation
An air layer higher than atmospheric pressure 1% ~ 5% (i.e. 100 ~ 500 kgf/m2, 1 kgf =9.80665 Newton) is made between the plane bottom and the running surface, so that the plane can be separated or partially separated from the running surface. This layer of pressurized air is called an air cushion.
According to the formation and maintenance methods of air cushion, air cushion can be divided into two types: peripheral injection type and air supply type. The peripheral jet air cushion (Figure 1) uses a fan to drive air into the air passage, and the air is ejected from the peripheral nozzle and turned outwards to form a jet air curtain, so that the internal pressure is higher than the external pressure and the aircraft rises. The air curtain seals the air cushion through the momentum change of the jet.
The pressure of the closed air cushion is related to the jet speed, air cushion height and jet angle of the air curtain. The pressurized air cushion is an atmospheric chamber (inflatable chamber) between the aircraft and the flight surface. Driven by the fan, air enters the air chamber and is discharged from the bottom. The air flow is blocked after flowing through the air chamber, and the air is transformed from dynamic pressure head to static pressure head, resulting in pressurization. The pressure of air cushion is related to air flow and air cushion height.
Based on the principle of air cushion lifting, air cushion handling platform, air cushion boat and air cushion train can be manufactured. Installing a flexible skirt at the nozzle outlet will greatly reduce the lifting force of the buffer pad and open up a broad prospect for practical use. For example, the application of flexible apron in hovercraft makes the hovercraft transition from experimental research stage to engineering practical stage.
The application of various aprons has greatly changed the form of nozzles. At first, the nozzle without apron was replaced by "ham" apron, and then gradually developed into ring apron and pocket finger apron. Geometric parameters in pocket finger apron, such as pocket finger depth ratio, skirt height to skirt width ratio, nozzle area ratio and nozzle position, also change as needed. Later, other forms of aprons appeared, such as cylindrical inflatable apron (Figure 6), peripheral cylindrical apron (Figure 7) and so on.
The calculation of flow, pressure, cushion height and related geometric parameters of air cushion is called the calculation of lift characteristics of air cushion. There are many theories describing the characteristics of cushion lift, and many experimental data have been published. For inflatable air cushion, inflation theory is widely used. Thin nozzle theory and exponential theory are widely used for peripheral jet air cushion. On the apron problem, the theory of jet along the wall was developed. After the appearance of pocket finger cuff, a set of formulas for calculating the cushioning characteristics of pocket finger cuff and unbalanced jet theory were established in China.
At present, the research trend of air cushion lift performance is to further reduce the relative air cushion lift height to save energy, and consider adopting low airbag pressure ratio and low resistance skirt type. In addition, the influence of the characteristics of the whole gas supply system on the aircraft performance is also studied. For hovercraft, due to the joint action of air cushion and apron, the seakeeping and wave-making characteristics of hovercraft are far more complicated than those of ordinary ships. The wave-making characteristics of hovercraft will involve the changes of the ship's wetted area, air cushion volume and discharge height, thus affecting the resistance and seakeeping.
Baidu encyclopedia-air cushion shoes
Baidu encyclopedia-air cushion