Views:0 Author:Site Editor Publish Time: 2020-07-04 Origin:Site
Installation process of coupling
For the coupling and the shaft with a corresponding clearance ，we can install directly after clean it or lubricate the grease;If the transition fit and interference amount are not very large, or there are special requirements for the fit (such as installed precision parts), the press-in method can be used, but need pressed equipment.The hot assembly work of couplings is often used in the installation of heavy equipment, such as large motors, compressors and rolling mills, because the couplings and shafts in this type of equipment are usually connect together with an interference fit.several assembling methods for interference fittings: press-fitting, low-temperature cold assembly, and hot-sleeve assembly.The cooling shrink assembly method generally uses liquid nitrogen as a cold source,also requires a certain thermally insulated container, so it can only be used when conditions permit.
The principle of hot charging is to heat the container (hole) to expand its diameter, then install the container (shaft) into it. After cooling, the machine will reach the required strength.In fact, the heating expansion value must larger than the interference value ,so as to ensure a smooth installation without serious accidents ;such as shaft and hole jamming due to the cooling shrinkage of the container during the installation process.At the same time, in order to ensure a large meshing force(bonding strength), the bonding surface must be processed, but not too smooth, because a certain surface roughness (generally Ra3.2) can be flattened After cooling, the bonding strength of the internal and external parts will be greater, and can transmit more large torque.
How to choose the heating method?
The method of heating the container to the required temperature should be selected according to the site conditions, the size, quantity and requirements of the heated parts.General heating methods include: solid fuel heating, hot dip heating, oxygen-acetylene flame heating, torch heating, electric heating, etc.If conditions permit, it can be heated in a special furnace (such as a flame heating furnace, a salt bath furnace, a resistance furnace, etc.). When the site conditions do not allow, a simple stove can be built and heated with solid fuels such as firewood and coke.If conditions permit, gas or liquid fuel can also be used for combustion. Dipping heating is usually only used for smaller couplings (with an inner diameter below 100mm). The method is simple and the average heating.
Oxy-acetylene flame heating method: When heating small parts or parts of larger spares, its simple but requires more skills to prevent overheating to burnout of parts.For large couplings, multiple sets of oxy-acetylene flame heating can be used together with torches, which works well.Although the electric heating method is a better way, it requires special equipment, which limits its use at the installation site.
What is the most common accidents in practical when assembley pipe flexible coupling?
1 The axis is installed crooked, and the coupling cannot be installed.
To prevent this type of accident,you have to pay attention to this two aspect : first ,calibrating the axis, the position of the coupling hole and shaft,the position of the collision block must correct. Second, impact position must be selected well, the first and second steps must be light. After entering a certain distance (about 1/3), they can be slammed with force.
2. Other accidents may include: the block pulley moves backwards due to the position being not fastened, the hoist chain slides down, insufficient fuel, fire alarm, etc., have to pay attention in advance, and carefully check during the tool preparation and operation training stages.
3.When bearings, mechanical seals and other precision components have been installed on the spindle in advance, it is prohibited to hit the coupling with force. Otherwise easy damage to the precision components.