The Thermal Characteristic Analysis Of Motorized Spindle Of NC Lathe

The improvement of processing technology can greatly improve the production efficiency and the saving cost. It is the development direction of mechanical sector. The high efficiency machine tools are completed the first condition of efficient manufacturing process. While the technology of motorized spindle plays a very important role in the field of efficient manufacturing. Compared with the traditional transmission mode, motorized spindle uses the built in motor, which cancels the middle rocking link, and really does "zero transmission". So far, we still know little about the thermal properties of electric spindle, which largely restricted the electric spindle technology to be widely used. What's more, in the high speed processing of operation, the motorized spindle may out of order due to the fever, and there even no time to issue alarming signals. The calorific value of electric spindle is mainly from motor's stator and rotor, and the friction heat of bearing. The accumulated heat will lead to temperature distortion of machine tools. However, the temperature distortion of electric spindle has become one of the most important aspects to the precision of machine tools. The mismachining tolerance due to thermal deformation of machine tools is nearly 60% to 80% of total processing error.This topic gives finite-element analysis to spindle's thermal properties, improves the temperature distribution, reduces the temperature rise and lessens the spindle thermal deformation. This thesis calculates the fever of electric spindle motor and the loss fever of bearing's friction, analyzes the capacity of convection heat on cooling water and seal. On this basis, the electric spindle thermal analysis model was built, and analyzed with large-scale finite element analysis software. At last, the main measures to improve the thermal properties of electric spindle were put forward. One of the measures is to carry circulatory water cooling on bearing outer. After improving of the electric spindle model and finite-element analyzed again, the results show that this method has an obvious effect on improving the temperature distribution of bearing. Electric spindle is the ideal structure form in spindle system of numerical control machine. The improvement of technical level and the products quality has an important theoretical significance and practical value in the field of numerical control machine of our country.