Twist
The twist of the shaft is a computing volume when the work of the calculated shaft is calculated, and it measures the length of the twist angle per meter. The torsional deformation of the shaft should affect the performance and working accuracy of the machine. For example, the torsional angle of the internal combustion engine camshaft will affect the correct opening and closing time of the valve; For a shaft with a risk of vibration and the axis in the manipulation system, there is a large twisting rigidity.
Skills requirement
1. Machining accuracy 1) Dimensions of size accuracy shaft parts The size accuracy mainly refers to the diameter size accuracy of the shaft and a shaft length accuracy. According to the requirements of the use, the accuracy of the main aes diameter size is usually IT6-IT9, and the precise neck can also reach IT5 level. The length of the axis is usually specified as the nominal size, and the length of the steps of the ladder shaft can be given corresponding tolerance according to the requirements. 2) Geometric accuracy shaft parts are generally supported on the bearings with two axle necks. These two shaft necks are called supportive necks, and they are also assembly benchmarks of the shaft. In addition to the size accuracy, it is generally required to support the geometric accuracy (roundness, cylindrical) of the neck. For general accuracy, the geometric shape error shall be limited to the diameter tolerance range. When it is required to be high, the allowable tolerance value shall be specified on the part of the part. 3) Mutual position accuracy of the axis parts of the axial parts (the neck of the moving part of the moving part) compared to the coales between the support axle neck is a common requirement for the accuracy of each other. The axis of normal accuracy, combined with accuracy to support the radial round of the nephew, is generally 0.01-0.03mm, and the high precision shaft is 0.001-0.005mm. In addition, the accuracy of the mutual position also has the same axis of the inside and outside cylindrical surface, the verticality requirements of the axial positioning end surface and the axis line. 2. The surface roughness According to the precision of the mechanical, the speed of operation is high, and the surface roughness requirements of the shaft parts are different. Under normal circumstances, the surface roughness of the support of the nephew RA is 0.63-0.16 μm; the surface roughness RA value with the surface of the neck is 2.5-0.63 μ
