The interference fit problem of hole and shaft parts is often encountered in the process of mechanical equipment maintenance and assembly. However, due to the lack of conditions for the implementation of modern assembly technology, the interference assembly of hole and shaft parts by thermal expansion method is a commonly used technical means in actual construction.
How to calculate the heating temperature according to the interference amount, control the heating process and prevent the heated parts from overheating in the process of interference assembly of hole and shaft parts, we can use automobile assembly machinery gear cold assembly industrial refrigerator for cold assembly.
Heating assembly method, interference fit hole and shaft interference fit are practical problems in the installation and maintenance of mechanical equipment. For the installation of interference fit parts, press in assembly method, low temperature assembly method (or cold assembly method, cold assembly method) and heating assembly method (or hot assembly method, hot assembly method) can be selected.
Among them, the press in assembly method is a kind of assembly method that uses the huge pressure generated by pressure machinery (such as hydraulic press, mechanical press, etc.) to press the matched shaft and hole or other assembly parts together according to the assembly reference on the drawing. The press assembly method can also be used with heating assembly method or low temperature assembly method, which has large interference and strong reliability. However, due to the special pressure machinery and the corresponding mold, the application scope of the press assembly method is limited. When the operation site does not have the assembly conditions of pressing method, other assembly methods can only be selected. Low temperature and heating assembly are the assembly methods that use the principle of thermal expansion and cold contraction to reduce the shaft or shaft parts with interference fit to a certain temperature or heat the hole parts to a certain temperature, so as to temporarily eliminate the interference between holes and shafts, and then quickly assemble the shafts and holes according to the design requirements.
In the practical operation of industrial refrigerator, the heating assembly is easier to realize than the low temperature assembly, so the heating assembly method is widely used in the production practice. When selecting hot assembly, it must be carried out step by step. Otherwise, due to the improper assembly process, it is likely to cause difficulties in installation, improper installation and even damage to the assembled parts and components, resulting in installation failure.
When choosing the hot charging method, the important consideration is whether the assembled parts meet the requirements of the hot charging method, there are mainly two aspects. The first is that the workpiece should be able to eliminate the interference and a certain gap after heating, so as to ensure that the workpiece can be assembled together according to the design requirements; the second is to consider that the heating temperature of the workpiece should not be enough to cause the change of the metallographic structure of the workpiece, otherwise the mechanical properties of the assembled parts will be affected.