The number of axles refers to the number of axles with tires under the car.
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A shaft is a cylindrical object that is threaded in the middle of a bearing, wheel or gear, but a few of them are square. A shaft is a mechanical part supporting a rotating part and rotating with it to transmit motion, torque or bending moment. It is in the shape of metal rod, and each section can have different diameters. The rotating parts of the machine are installed on the shaft.
The structural design of the shaft is an important step to determine the reasonable shape and all structural dimensions of the shaft. It is related to the type, size and position of the parts installed on the shaft, the fixing mode of the parts, the nature, direction, size and distribution of the load, the type and size of the bearing, the deformation of the shaft and other factors.
Common shafts can be divided into crankshaft, straight shaft, flexible shaft, solid shaft, hollow shaft, rigid shaft and flexible shaft (flexible shaft) according to the structural shape of the shaft. The straight axis can be divided into:
① Rotating shaft, which can bear both bending moment and torque when working, is the most common shaft in machinery, such as the shaft in various reducers.
② The spindle is used to support the rotating parts, which only bear the bending moment and do not transmit the torque. Some spindles rotate, such as the axle of railway vehicles, while others do not, such as the axle supporting pulley.
③ The transmission shaft is mainly used to transmit torque without bearing bending moment, such as the long optical shaft in crane moving mechanism, the driving shaft of automobile, etc. The material of the shaft is mainly carbon steel or alloy steel, or nodular cast iron or alloy cast iron. The working capacity of the shaft generally depends on the strength and rigidity, and the high speed also depends on the vibration stability
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