Study On The Thermal Properties Of Mill-turn CNC Direct Drive Turntable

With the development of our country’s manufacturing industry, high-speedprocessing machine gradually became a clear direction of development. The NCmachine tool technology level and performance were directly affected and influencedby the technology level of the functional components and the performance. Thedevelopment speed of the host was also restricted by those factors. Today, though thescience and technology continually progressed and increasingly fierce competitionexisted in the market, the further improvement of the machining accuracy has beenstill hindered by the machine tool thermal problems. So the thermal controltechnology was one of the key technologies, which was badly in need of solution inthe development of high precision machine tool work. NC rotary table was one part ofthe high speed and high precision machine tool’s main functional components. Soimproving its thermal characteristics and reducing the temperature rise and thermaldeformation occupied an important position in the process of design and research ofthe turntable.This task was set in the national science and technology major of2010--movingbeam without ram vertical milling and turning composite processing center (topiccode:2010ZX04001-032).The research object was the direct drive turntable of thecomposite processing center. The study objective was improving thermalcharacteristics. Specific content was as follows:1. Do three-dimensional modeling for the direct drive turntable with Solid Works.And make sure the main heat source and the boundary conditions of the turntable.2. Analyze the main heat source (bearings, motor rotor and stator) and calculatethe quantity of heat.3. Calculate the convective heat transfer coefficient (i.e. the boundary conditionsof finite element thermal analysis model) of each part according to the heat transferprinciple and related formula.4. Mesh the turntable and calculate the temperature field distribution with ANSYSWorkbench.Then analyze the changes of temperature.5. According to the results of temperature field calculation, we can analyze thechanges of temperature field and temperature rise of the turntable’s key parts.6. Find out the main factors that influence the turntable’s thermal deformation.Then put forward the scheme that can effectively improve the thermal characteristicsof turntable.