What is the price of central digital currency
2019 August 21st, the official account of WeChat central bank released two articles on digital currency.
Generally, the excellent digital currencies are mostly imported procts, such as bitcoin, Leyte coin, ether coin and so on. However, the domestic Yuanbao coin, Ruitai coin, bitcoin and the tokens of different crowdfunding projects of European crowdfunding are excellent digital currencies
digital currency (English: digital currency) is an alternative currency in the form of electronic currency. At present, no central bank of any government has indicated that it will issue digital currency, and digital currency does not have to have a benchmark currency and a central bank
it is different from the virtual currency in the virtual world, because it can be used for real goods and services transactions, not limited to online games. The early digital currency (digital gold currency) is a form of electronic currency named after the weight of gold. Today's digital currency, such as bitcoin, lightcoin and ppcoin, is an electronic currency created, issued and circulated by check sum cryptography
monetary policy, like tax, police, court and other state machines, is the foundation of modern state operation and an important part of state machine. As long as there is no fundamental change in the social organization form of the state, the monetary system based on the national credit will always exist, and bitcoin and other virtual currencies will not become the standard currency of a country. Bitcoin is actually just the use of technology, which is at most an asset, not a real currency< Of course, credit money is prone to inflation. In a sense, people's concern about bitcoin reflects people's worry about inflation under the condition of credit currency. Therefore, central banks should strengthen liquidity management, reasonably regulate money supply and keep prices basically stable.
To calculate the helical gear parameters, you need to know the basic parameters:
normal molus M_ n. Number of teeth Z, normal pressure angle α_ n. Helix angle β
generally, the crown height coefficient h * is 1, and the root height coefficient C * is 0.25. If there is displacement, it is necessary to calculate the displacement: x
the following is the basic parameter
end face molus: M_ t=m_ n/cos β
Calculation formula of pressure angle at the end face: Tan α_ t)=tan ( α_ t)/cos( β)diameter of dividing circle: D = m_ n × z/cos( β)
addenm circle diameter: no displacement: Da = D + 2 × m_ n × H * with displacement: Da = D + 2 × m_ n × H * + x)
root circle diameter: no displacement: DF = D-2 × m_ n ×( H * + C *) with displacement: DF = D-2 × m_ n ×( H * + C * - x)
diameter of base circle: DB = D × cos α_ t)
in addition, there are more important dimensions, such as normal pitch, end pitch, etc., which can be obtained by referring to relevant manuals
Extended data:
judgment of helix rotation direction: first, we make the gear axis vertical, if the right height of helix is right rotation; On the contrary, the height on the left side of the helix is left-handed
end face and normal surface parameters:
end face: the plane perpendicular to the gear axis, and the parameters on the end face are generally added with subscript t
normal plane: the plane perpendicular to the helix, and the parameters on the normal plane are generally subscript n
(1) pitch and molus: = t= π
(2) pressure angle: generally, the parameters in normal plane are standard parameters
The correct meshing condition: the helix angle must be equal in size and opposite in direction. The normal molus m is equal to the normal pressure angleB. geometric dimension calculation: in calculation, the calculation formula of spur gear can be directly applied to the end face of helical gear because a pair of helical gear transmission is equivalent to a pair of spur gear transmission on the end plane
there are many kinds of gear transmission, among which the efficiency of helical gear is very high, for example, the efficiency of spur gear transmission is lower than that of helical gear transmission
Like spur gear mechanism, helical gear can be used to improve the load capacity of transmission by recing the center distance a, which can be used for high-speed operation. Helical gear recer is a new type of recer. The helical gear recer is small in volume, light in weight and good in economy Advantages:(1) good meshing performance: the meshing process between helical cylindrical gears is an excessive process, and the force on the teeth is graally from small to large, and then from large to small; Helical gear is suitable for high speed and heavy load
(2) large coincidence degree: the increase of coincidence degree can improve the bearing capacity of gear. So the life of the gear is prolonged. The coincidence degree mainly depends on the meshing time, while the long meshing time and large contact area of helical gear rece the stress. The transmission is stable and the economy is increased
(3) compact structure: the less the minimum number of teeth, the more compact the structure