Shafting mechanical structure for eliminating thermal stress and thermal gaps among different materials

Abstract

The invention provides a shafting mechanical structure for eliminating thermal stress and thermal gasps among different materials. A structural form for switching over structural parts made of different materials by using pins is used in the structure. The shafting mechanical structure consists of a shell, an internal bearing seat and the pins, wherein the shell is made of LY12 aluminum alloy; the internal bearing seat is made of 45 steel; both the periphery of the shell and the periphery of the internal bearing seat have 6 pin holes of which the positions are matched with one another; the pins are made of cast copper; the pins and the shell have the sizes which are matched with those of the pin holes in the internal bearing seat and have certain interference magnitude to ensure that the pins and the shell are tightly connected with the internal bearing seat; and a 1mm radial clearance is formed between the shell and the internal bearing seat. The quantity, the sizes and the interference magnitude of the pins in the whole structure are optimized by finite-element analysis. By the structure, extrusion thermal stress between the shafting shell and the internal bearing seat during severe variation of ambient temperatures can be avoided, and the thermal gaps can be eliminated; and simultaneously, the fastening state between the shell and the internal bearing seat and the mechanical rigidity of the whole structure can be ensured.

Description

technical field [0001] The invention belongs to the field of mechanical design, and relates to a mechanical structure form for eliminating the thermal stress and thermal gap that occur in the internal shafting mechanical structure due to different materials when the working temperature changes. Background technique [0002] In the field of modern machinery manufacturing, aluminum is often used in some structures that do not require very strict mechanical properties because of its low density compared to steel, low price, and easy processing. However, some key components in the shafting mechanical structure (such as bearing housings, etc.) should still be made of steel to ensure their mechanical properties. The combination of steel and aluminum parts is used more and more in the field of mechanical design today. However, due to the large difference in the thermal expansion coefficients of steel and aluminum when using traditional methods for assembly, in aerospace and other a...

AI Technical Summary

Problems solved by technology

If a mechanical material with a similar thermal expansion coefficient is used, for example, the inner bearing housing is made of 45 steel, and the bearing shell is replaced with a titanium alloy with a similar thermal expansion coefficient. , the processing technology is more difficult, the weight of the mechanical structure is not easy to control and other factors, so it is difficult to be widely used

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